New pasting paper made of glass fiber nonwoven comprising carbon graphite

ES 2 622 752 T3

DESCRIPTION

New battery plate made of non-woven fiberglass containing carbon graphite

Background of the invention

Lead-acid batteries are characterized by being inexpensive and very reliable. As such, they are widely used as a source of electrical power for starting motor vehicles, golf carts, and other electric vehicles. In recent years, various measures have been considered to improve fuel efficiency in order to avoid air pollution and global warming. Examples of motor vehicles subject to fuel efficiency improvement measures that are being considered include vehicles with an idle shutdown system (ISS vehicles) in which the engine is stopped when the vehicle is not in motion to avoid idling. unnecessary engine operation and to reduce engine operating time.

In an ISS vehicle, the number of engine starting cycles is higher, and the lead-acid battery discharges a high electrical current during each start. Also, the amount of electricity generated by the alternator in an ISS vehicle is less, and the lead-acid battery charges intermittently. In fact, the battery charge is often insufficient. In other words, the battery is in a partially charged state known as PSOC (ie, partially charged state). Consequently, a lead-acid battery used in an ISS vehicle is required to have a capacity such that the battery is charged as much as possible in a relatively short time. In other words, the lead-acid battery must have a higher charge acceptance. Therefore, improvements in the charge acceptance of a lead-acid battery are desirable.

Lead-acid batteries typically have a shorter lifespan when used in the PSOC regime than when the battery is used in a fully charged state. A reason for a shorter life under the PSOC regime is believed to be due to repeated charging and recharging of the battery in an insufficient state of charge. This way of charging and recharging the battery negatively affects the battery electrodes or plates. For example, during discharge, lead sulfate forms on the negative plate, which undergoes progressive thickening during charging and tends not to be restored to metallic lead. Improving charge acceptance can prevent the battery from being charged and recharged when it is in an insufficient state of charge, which can inhibit lead sulfate thickening due to repeated charging and discharging. This can increase the life of the lead-acid battery.

Also, there are inherent disadvantages to lead-acid batteries. For example, during the discharge of the lead-acid battery, the lead dioxide (a really good conductor) on the positive plate is converted to lead sulfate (an insulator). Lead sulfate can form an impermeable layer that encapsulates lead dioxide particles, limiting lead dioxide utilization often to less than 50 percent capacity, and more commonly to around 30 percent. The low utilization rate is a key reason why the power and energy performance of a lead-acid battery is inherently less than optimal. This insulating layer is believed to cause increased internal resistance in the battery. Improved charge acceptance can also help reduce problems associated with lead sulfate formation. In addition, lead-acid batteries that have a separator typically exhibit a voltage drop when used in low-temperature operating cycles (multiple start-up processes). This disadvantage prevents the acceptance of such battery systems for wider use.

Brief summary of the invention

Embodiments of the invention provide an absorbent glass mat (AGM) battery. The battery includes a positive electrode, a negative electrode, and a nonwoven fiber mat spacer located between the positive electrode and the negative electrode. The nonwoven fiber separator contains a glass fiber blend containing multiple first glass fibers with diameters between 8 pm and 13 pm and multiple second glass fibers with diameters of at least 6 pm. The multiple second glass fibers include a silane material size. The nonwoven fiber separator also includes an acid resistant binder that binds the multiple first and second glass fibers together to form the nonwoven fiber separator. The nonwoven fiber separator further contains a wetting component applied to the nonwoven fiber separator to increase the wettability of the nonwoven fiber separator so that the nonwoven fiber separator has or exhibits an average water absorption height of at least 1.0 cm after exposure to water for 10 minutes, carried out according to the ISO 8787 method. The nonwoven fiber separator further contains a conductive material disposed on at least one surface of the nonwoven fiber separator so that when the nonwoven fiber separator is positioned adjacent the positive or negative electrode, the conductive material contacts with the positive or negative electrode. The nonwoven fiber separator has an electrical resistance of less than 100,000 ohms per square to allow the flow of electrons around the nonwoven fiber separator.

The glass fiber blend contains first glass fibers with a diameter of between 8 pm and 13 pm and second glass fibers that include a silane material size and a diameter of at least 6 pm. In a preferred embodiment, the first and second glass fibers have different diameters.

ES 2 622 752 T3

In another embodiment, the nonwoven fiber separator is provided with a nonwoven fiber separator for an AGM battery. The nonwoven fiber separator includes a glass fiber blend containing multiple first glass fibers with diameters between 8 pm and 13 pm and multiple second glass fibers with diameters of at least 6 pm. The multiple second glass fibers include a silane material size. The nonwoven fiber separator further contains an acid resistant binder that bonds the multiple first and second glass fibers to form the nonwoven fiber separator. A wetting component is applied to the nonwoven fiber separator to increase the wettability of the nonwoven fiber separator so that the nonwoven fiber separator has an average water absorption height of at least 1.0 cm after exposure to water for 10 minutes, carried out according to the ISO 8787 method. The nonwoven fiber separator further includes a conductive material disposed on at least one surface of the nonwoven fiber separator such that when the nonwoven fiber separator is positioned adjacent the positive or negative electrode of a lead-acid battery , the conductive material makes contact with the positive or negative electrode. The nonwoven fiber separator has an electrical resistance of less than about 100,000 ohms per square to allow the flow of electrons around the nonwoven fiber separator.

In another embodiment, a method of manufacturing a nonwoven fiber separator for use in a lead-acid battery is provided. The method includes providing a glass fiber blend that includes multiple first glass fibers with diameters between 8 pm and 13 pm and multiple second glass fibers with diameters of at least 6 pm. The multiple second glass fibers include a silane material size. The method may include applying an acid resistant binder to the glass fiber mixture to join the glass fiber mixture to form the nonwoven fiber separator. The method also includes applying a conductive material to at least one surface of the nonwoven fiber separator so that when the nonwoven fiber separator is positioned adjacent to the positive or negative electrode of a battery, the conductive material makes contact with the positive or negative electrode. The nonwoven fiber separator has an electrical resistance of less than about 100,000 ohms per square to allow the flow of electrons over the nonwoven fiber separator. The method further includes applying a wetting component to the nonwoven fiber separator to increase the wettability of the nonwoven fiber separator so that the nonwoven fiber separator has or exhibits an average water absorption height of at least 1, 0 cm after exposure to water for 10 minutes, carried out according to the ISO 8787 method.

Brief description of the drawings

The present invention is described in conjunction with the attached Figures:

- Figure 1 illustrates an exploded perspective view of the assembly of a battery cell.

- Figure 2 illustrates an assembled cross-sectional view of the battery cell assembly of Figure 1.

- Figs. 3A-3C illustrate cross-sectional views of various configurations of an electrode or plate and a mat of nonwoven fibers.

- Figure 4 illustrates a process for preparing an electrode or plate having a mat of non-woven fibers disposed on or near a surface of the electrode or plate.

- Figure 5 illustrates a method of manufacturing a lead-acid battery plate.

- Figure 6 illustrates a method of manufacturing a non-woven fiber mat according to embodiments of the invention.

In the attached figures, similar components and / or features may have the same reference numeral indicator. Furthermore, various components of the same type can be distinguished by writing after the reference indicator a letter that distinguishes between similar components and / or characteristics. If only the first numerical reference indicator is used in the specification, the description is applicable to any of the components and / or similar characteristics having the same first reference indicator, regardless of the suffix letter.

Detailed description of the invention

The description that follows provides exemplary embodiments only, and is not intended to limit the scope, applicability, or configuration of the description. Rather, the following description of the exemplary embodiments will provide those skilled in the art with a description that allows one or more exemplary embodiments to be implemented. It should be understood that various changes can be made to the function and arrangement of elements without departing from the scope of the invention, as set forth in the appended claims.

Specific details are included in the description that follows to provide a clear understanding of the embodiments. However, one of ordinary skill in the art will understand that the embodiments can be practiced without these specific details. For example, the processes and other elements of the invention can be shown as components in block diagram form in order not to obscure the embodiments with

ES 2 622 752 T3 unnecessary details. In other cases, well-known processes, structures, and techniques can be shown without providing unnecessary detail in order not to obscure the embodiments.

It is also noted that the individual embodiments can be described as a process that is represented as a flow chart, a flow chart, a data flow chart, a structure diagram or a block diagram. Although an organization chart can describe operations as a sequential process, many of the operations can be carried out in parallel or simultaneously. Also, the order of operations can be reordered. A process can end when its operations are complete, but it could have additional stages not covered or included in a figure. Otherwise, not all operations in any particularly described process can occur in all embodiments. A process can correspond to a method, a function, a procedure, a subroutine, a subprogram, and so on. If a process corresponds to a function, its termination corresponds to a return from the function to the function that called it or to the main function.

The description that follows provides exemplary embodiments only, and is not intended to limit the scope, applicability, or configuration of the description. Rather, the following description of the exemplary embodiments will provide those skilled in the art with a description that allows one or more exemplary embodiments to be implemented. It should be understood that various changes can be made to the function and arrangement of elements without departing from the scope of the invention as set forth in the appended claims.

Embodiments of the invention provide nonwoven fiber mats (hereinafter reinforcing mats) that have an electrically conductive surface that encourages the flow of electrons to and / or from the battery plates, and that also includes a wetting component to enhance the wettability of the mats. The reinforcement mats can be used to reinforce the plates in lead-acid batteries, or in other batteries, or they can be used in spacers located between electrodes, for example in battery applications with Absorbent Glass Mat (AGM). Reinforcing mats are acid resistant nonwoven mats, such as glass mats, or a mixture of polyolefin fibers and glass fibers.

Electron flow is promoted by including a mat with a conductive surface (s) and / or other conductive pathway. The improved electron flow lengthens the life of the battery, especially in lead-acid batteries where continuous discharge and recharging of the battery results in degradation of the battery electrodes. For example, during the discharge of the lead-acid battery, the lead dioxide (a good conductor) on the positive electrode plate is converted to lead sulfate, which is generally insulating. Lead sulfate can form one or more impermeable layers that encapsulate lead dioxide particles, which can limit the use of lead dioxide, and therefore the battery, to less than 50 percent of its capacity, and in some cases around 30 percent. The lead sulfate insulating layer can also lead to increased battery resistance. The effect may be a decrease in the electrical current supplied by the battery and / or the battery life. In some embodiments, the mat can offer a significant improvement (decrease) in voltage drop when operating in idle start cycles at low operating temperatures (multiple start-up procedures) compared to existing systems. Conductive backing mats can replace other plate backing media, such as paper, currently used in lead-acid batteries or other types of batteries. The conductive reinforcing mat provides several advantages over current plate reinforcing means, such as non-dissolution in the electrolyte (eg sulfuric acid); improvement of resistance to vibrations, reduction of detachment of plates, strengthening or reinforcement of the plate; and / or provision of good dimensional stability, which can allow easier guidance or manipulation during battery plate manufacturing processes.

In relation to the conductive properties of the conductive backing mat, the electrically conductive surface of the mat can provide an additional path for electron flow. The path provided by the mat is typically separate from the path provided by the battery conductive plate or grid. Multiple pathways for electrons (eg mat and conductive plate) allow electrons to flow through either, or both, conductive backing mat or conductive plate / grating, depending on which path offers the least electrical resistance. In this way, as the electrode degrades due to the formation of lead sulfate, numerous pathways for electrons are maintained, thereby increasing the life of the battery. In some embodiments, the battery may include a battery separator that also contains a conductive material. The battery separator can provide additional pathways for electron flow in addition to the conductive mat and conductive plate or grid. Such a separator can be particularly useful in AGM batteries discussed here. In some embodiments, the spacer may contain a non-conductive spacer layer.

The conductive reinforcement mat also provides excellent plate or electrode reinforcement due to its excellent strength properties. The conductive backing mat may also have a relatively small or reduced mat size. Relatively thin fiber mats reduce the overall volume that the mat occupies, allowing a greater amount of electrolyte and / or active material paste to be used within the lead-acid battery. Thinner mats also improve processing efficiency by increasing the length of the mat on the processing coils, which decreases the frequency of coil changes. In some embodiments, the conductive backing mat may have a thickness of less than 10 mils (i.e., 0.0254 cm (0.010 inches) or 254 pm), and more commonly less than 9 mils.

ES 2 622 752 T3 (ie, 0.0228 cm (0.009 inches) or 229 pm). In one embodiment the conductive reinforcing mat is between about 6 mils (0.006 inches), 152 pm) and about 8 mils (0.008 inches), 203 pm) thick. or between 6 mils (0.0152 cm (0.006 inches), 152 pm) and 7 mils (0.0178 cm (0.007 inches), 178 pm) approximately.

In some embodiments, the conductive reinforcing mats can include a combination of electrically insulating fibers and a conductive material. The mat made of these electrically insulating fibers can have an electrical resistance greater than about 1 million ohms per square (sheet resistance). In one embodiment, the electrically insulating fibers can include glass fibers, polyolefin fibers, polyester fibers, and the like. For convenience in describing embodiments, the present description will refer primarily to glass fibers, although it should be understood that other electrically insulating fibers may be used.

The electrically conductive material may include a layer or mat of conductive fibers or a layer of other conductive materials, such as a metallic foil or film that is positioned on top of the electrically insulating fiber layer. In many embodiments the conductive material is a non-metallic material. In some embodiments the conductive material may include a coating of conductive material applied to or on the fiber mat. In a specific embodiment the conductive material can be added to a binder material that is applied to the multiple insulating fibers during the manufacture of the fiber mat, or that is sprayed onto the previously manufactured fiber mat. The conductive material can include conductive polymers (eg, polyanilines), carbon material (eg, carbon black, activated carbon, graphite, carbon nanofibers, carbon nanotubes, graphene, CNS (carbon nanostructure), and the like. In one embodiment Specifically, the conductive material may include conductive fibers that are at least partially disposed within and / or entangled with a fiber mat having the insulating fibers. The conductive fibers can be mixed with the insulating fibers (eg glass fibers, polymer fibers, and the like) to form a mat that is conductive. In an exemplary embodiment, graphene or CNS can be used due to their high electrical conductivity and being inert to sulfuric acid. CNS can be used more commonly because it can be easily dispersed in water.

The conductive backing mat is typically located within the battery so that the electrically conductive / conductive material / layer contacts the active paste on the battery electrodes. The electrically conductive layer of the mat may be disposed across substantially the entire surface of the conductive backing mat, such that the electrically conductive layer is substantially the same size and shape as the conductive backing mat. In this way the electrically conductive layer provides a large conductive surface that makes contact with the electrode.

The conductive reinforcing mats can have an overall tensile strength of at least 13.5 kg / 7.62 cm (30 pounds / 3 inches) and more commonly of at least 15.75 kg / 7.62 cm (35 pounds). / 3 inch) (1 pound = 0.45 kg; 1 inch = 2.54 cm). To achieve this tensile strength, the nonwoven fiber mat can have a machine direction tensile strength of at least 9.9 kg / 7.62 cm (22 lbs / 3 inches) and a resistance to the cross-machine direction pull of at least 13 pounds / 3 inches (5.85 kg / 7.62 cm). The description of kg / 7.62 cm (pounds / 3 inches) generally refers to a mat strength test method in which a rectangular piece measuring 7.62 cm by 30.48 cm (3 inches by 12 inches) inches) of the fiber mat is subjected to tensile stress until the mat cracks, either by breaking or tearing. Mats that have a tensile strength less than 9.9 Kg / 7.62 cm (22 pounds / 3 inches) in machine direction and less than 5.85 Kg / 7.62 cm (13 pounds / 3 inches) inches) in the cross-machine direction may not have sufficient strength to support winding and rewinding during processing and / or to reinforce the plates of lead-acid or other batteries.

In some embodiments, the conductive backing mats can include a mixture of two or more large diameter fibers of different sizes. The description of large diameter fibers generally includes fibers whose diameter ranges from about 6 pm to about 30 pm in one embodiment, and from about 8 pm to about 20 pm in another embodiment. Therefore, the term large within a preferable meaning of the present invention means that no glass fibers with a fiber diameter below 5 pm are present. For example, in one embodiment, a conductive reinforcing mat may include a mixture of first glass fibers having fiber diameters in the range of 8 pm to 13 pm and second glass fibers with fiber diameters of at least 6 pm approximately. The preferable diameter range is between 6 pm and 7 pm. In some embodiments, the second glass fibers include silane material sizing to improve their adhesive properties and / or acid resistance. In one embodiment, the nonwoven fiber mats include at least 25% of each of the first and second glass fibers. Glass fibers typically have fiber lengths ranging from about 1/3 inches to about 1 1/3 inches, although fiber lengths are more commonly between 0.85 centimeters. (1/3 inch) to roughly 1.9 (3/4 inch) or 2.54 centimeters (1 inch).

Conductive reinforcing mats also include a binder that bonds the glass fibers together and that bonds the conductive fibers to the glass fibers when conductive fibers are used as the conductive material. The binder is typically applied to glass fibers such that the binder makes up about 5% to 45% by weight of conductive reinforcing mats, about 15% to 35% by weight of conductive backing mats.

ES 2 622 752 T3 conductive backing mats and more commonly between about 5% and 30% by weight of conductive backing mats. The binder is generally an acidic and / or chemically resistant binder (eg, an acrylic binder) that provides the durability to withstand the acidic environment throughout the life of the battery and the strength to withstand the plate gluing operation. In a specific embodiment, the binder can also include the conductive material. For example, the conductive material (eg, graphene, graphite powder, and the like) can be dispersed within the binder.

According to one embodiment, a fiber mat (eg, glass fiber mat) can be coated with the conductive material to form the conductive reinforcing mat. This can be achieved by dip coating, curtain coating, spraying, dip and compression techniques, and the like. In another embodiment, the conductive material can be mixed with the binder and applied to the fiber mat during application of the binder. The latter process represents a single application step or process. The binder can help bond the conductive material to the mat. Having described various embodiments of the invention, further aspects will become more apparent with reference to the figures described below.

In some embodiments, the conductive material of the reinforcing mat can be non-metallic. The non-metallic conductive material coated mat can be used to reinforce electrode plates and can provide benefits described herein, such as improving electron transfer and output current, reducing internal resistance of the battery, improving acceptance of cargo and the like. It is believed that by using a non-metallic conductive material coated mat, be it a separator support mat or a plate reinforcing mat, the electrons do not have to pass through the point on the electrode where there is a greater resistance (for example, due to micro-cracks and the like). Electrons can flow freely over the conductive surface of the mat and choose the point of contact that exhibits minimal resistance. This benefit is much greater after the battery has been used for an extended period of time.

In addition to having conductive properties, the reinforcement mats also have absorption capacity that allows complete wetting of the electrodes. Such mats can also aid in the drying of the plate / electrode after the plate / electrode has been glued with a suspension of lead paste. The term "wettability", as used herein, refers to the ability of the mats to absorb or otherwise transport water and / or other solutions, such as a solution of water and acid, from one location. For example, when testing fiberglass mats for wettability or absorbency, a strip of the mat, which is often approximately 1 inch (2.54 cm) wide, 6 inches (15.24 cm) long and typically 0.1 to 3 mm thick, it can be vertically immersed in water or other solution for a specified time, for example 10 minutes. The distance or height of the water absorbed by the fiberglass mat from a surface of water or other solution indicates the ability of the mat to absorb or otherwise transport the water or solution. The test to determine the average water absorption height of the reinforcing mat can be performed according to the ISO 8787 method. In some embodiments, the absorption capacity can also improve the wettability of the electrolyte electrode.

The mats described herein increase the wettability of fiberglass mats by adding a wetting component to the fiberglass mats. The added wetting component provides a pathway for the water and / or the water / acid solution to evaporate. In one embodiment, the added wetting component assists in the transport of water and / or water / acid solution to a surface of the mat where the water and / or water / acid solution can evaporate. In some embodiments, the combination of the first glass fibers, the second glass fibers, and the wetting component can provide 4 or 5 times the wettability of a standard mat.

In one embodiment, the added wetting component may be a wettable component of an acid resistant binder that is used to bond the glass fibers of the mat together. The wettable component can be a hydrophilic functional group that increases the ability of the water and / or the water / acid solution to be absorbed into the interior of the glass mat or to flow along a surface of the glass mat. . In other embodiments, the wettable component may be a hydrophilic binder that is mixed or combined with the acid resistant binder to form a binder mixture. In some embodiments, the wettable component may contain starch, cellulose, stabilized cotton, a hydrophilic binder (eg, a polyacrylic acid-based binder), and the like. In some embodiments, the binder can protect the wettable component, such as cotton, from deterioration. In some embodiments, the glass mat may include only coarse glass fibers, or fibers with a fiber diameter of between about 6 and 30 µm. The wettable component can enhance such ability of the mat to absorb water and / or the water / acid solution and / or allow the water and / or the water / acid solution to flow primarily along one surface of the mat. reinforcement. Contact angle measurement according to ASTM D7334.

As used herein, the term "hydrophilic (or acidophilic) binder" refers to a binder with a contact angle with water (or 33% by weight sulfuric acid medium for acidophilic) of less than about 90 °, preferably less than 70 ° and more preferably less than 50 °. By testing the binder contact angle, the binder can be centrifugally coated onto a glass slide and then cured before being exposed to the above solution to measure the contact angle.

ES 2 622 752 T3

In some embodiments, the binder and wettable component can be added to the mat in up to about 20% LOI (Loss on Ignition). In other embodiments, a first binder that does not include a wettable component can be used to bond the thick glass fibers, and a second binder containing the wettable component (eg, a hydrophilic functional group) can be applied to the mat to enhance the wettability of the mat. The first and second binders can be mixed or blended together to form a single binder blend that is applied to coarse glass fibers.

In another embodiment, the added wetting component can be a fiber. The fiber may be a natural fiber, such as cellulose or stabilized cotton, or it may be a synthetic fiber such as polyester, or it may include a blend of natural and / or synthetic fibers (hereinafter component fibers). Stabilized cotton includes cotton filaments that are coated with an acid resistant binder and / or embedded in said binder. The component fibers may have a microfiber structure, or in other words, they may have fiber diameters of between about 0.01 and 10 µm, more frequently between about 0.5 and 3 µm. The absorbency / wettability of the component fibers may be better than that of glass fibers (eg coarse fibers in the range of 6 to 30 pm) due to the dimensions of the fibers (eg microfibers) and / or because the component fibers typically include hydrophilic functional groups, such as OH groups, COOH groups, and the like.

In some embodiments, the component fibers can be formed into a mat that is separate from the glass fiber mat, for example by applying the component fibers on top of a fiberglass mat. The component fiber mat can be bonded to the glass fiber mat such that the resulting combined mat has essentially two layers - a glass fiber layer and a component fiber layer. In some embodiments, a second component fiber mat may be attached to an opposite side of the glass fiber mat such that the resulting combined mat has essentially three layers - a glass mat sandwiched between two component fiber mats. In another embodiment, the component fibers can be mixed with the glass fibers so that the resulting mat includes a combination of entangled glass fibers and component fibers. An acid resistant binder can be used to bond the component fiber mat to the glass fiber mat, or it can be used to bond the entangled glass fibers and component fibers to form the reinforcing mat.

In one embodiment, the glass fiber mat may include primarily coarse fibers, or fibers with a fiber diameter of between about 6 and 30 µm. In some embodiments, other acid resistant fibers may be used in place of polyethylene fibers including glass, polypropylene fibers, polyester fibers, and the like. The component fibers (e.g. cellulose fibers) provide the backing mat with good wettability properties, assisting in the transport of water and / or a water / acid solution to the surface of the backing mat, where water can evaporate. and / or the water / acid solution.

In another embodiment, the fiberglass mat may include primarily glass microfibers, or fibers with a fiber diameter of between about 0.01 and 5 pm. The resulting reinforcing mat may include primarily or only glass microfibers that are entangled with the component fibers or that are bonded with one or more component fiber mats. Such a reinforcing mat can have exceptional wettability and absorption capabilities.

In some embodiments, the reinforcing mat may include a combination of acid-resistant coarse fibers (for example, fibers with a fiber diameter between 6 and 30 pm), acid-resistant microfibers (for example, fibers with a diameter of fiber between 0.01 and 5 pm), and the component fibers. Coarse acid-resistant fibers and microfibers are commonly glass fibers, although other acid-resistant fibers can be used. In some embodiments, the reinforcing mat may include about 15 to 85% of a combination of coarse glass fibers and microfibers, and about 15 to 85% of the component fibers. In another embodiment, the reinforcing mat may include about 40-60% of the coarse glass fibers, 20-30% of the glass microfibers, and 20-30% of the component fibers. The component fibers and microfibers can work synergistically to absorb water and / or the water / acid solution, and therefore can greatly improve the wettability and absorbency of the reinforcing mat. For example, glass microfibers are typically more wettable than coarse glass fibers. The microfibers, however, can be covered or hidden by the thick glass fibers and / or the binder and therefore not be exposed to the water and / or the water / acid solution.

In some embodiments, the binder having the wettable component (eg, a hydrophilic functional group) can be used to bond a reinforcing mat that includes the coarse glass fibers and the component fibers, or that includes the coarse glass fibers, glass microfibers and component fibers. The wettable component can further increase the wettability of the reinforcing mats, for example by providing another route for the transport of water and / or the water / acid solution and / or increasing the exposure of the water and / or the water solution. / acid to glass microfibers.

In another embodiment, the added wetting component can be a wettable solution that is added to the reinforcing mat. The wettable solution can be added to the backing mat to saturate the backing mat.

ES 2 622 752 T3 reinforcement, or to be spread over at least one surface of the reinforcement mat after drying of the wettable solution. The wettable solution can include a starch solution, cellulose solution, polyvinyl alcohol solution, polyacrylic acid solution, and the like. The wettable solution can be added to the mat after the mat is formed, for example by dip coating the backing mat in the wettable solution or by applying the wettable solution by spray coating, curtain coating and the like. After application of the wettable solution, the wettable solution can be dried to provide a path for the water and / or the water / acid solution to evaporate. The wettable solution may subsequently dissolve when exposed to an acidic environment, such as the battery electrolyte environment, so that the backing pad remains adjacent to the electrode after dissolution of the wettable solution.

According to any of the embodiments described herein, the addition of the wetting component to the backing pad can increase the wettability of the backing pad such that the backing pad exhibits an average water absorption height of at least 1, 0 cm after exposure to water for 10 minutes. The test to determine the average water absorption height of the reinforcing mat can be carried out following the ISO 8787 method. Similarly, the addition of the wetting component to the backing pad can allow the backing pad to have an average water / acid solution absorption height of at least 1.0 cm after exposure to the water / acid solution. acid for 10 minutes. This test is carried out in a similar way according to the ISO 8787 method. In other embodiments, the mean water absorption height and / or the mean water / acid solution absorption height may be at least 0.8 cm after exposure to the respective solution for 10 minutes. In other embodiments, the mean water absorption height and the mean water / acid solution absorption height may be greater than 1 cm after exposure to the respective solution for 10 min. As briefly described above, the addition of silane-sized glass microfibers to the backing mat can significantly increase the wettability / absorbency of the backing mat so as to increase the average water absorption height and / or the average absorption height of the water / acid solution.

Accomplishments

Figs. 1 and 2, respectively, show an exploded perspective view of a lead-acid battery cell 200 and an assembled cross-sectional view of the lead-acid battery cell 200. The lead-acid paste cell 200 may represent a cell used in either lead acid immersion batteries or Absorptive Glass Mat (AGM) batteries. Each cell 200 can provide an electromotive force (emf) of about 2.1 volts and a lead-acid battery can include 3 such cells 200 connected in series to provide an emf of about 6.3 volts or it can include 6 such cells. 200 connected in series to provide an emf of about 12.6 volts, and the like. Cell 200 includes a positive plate or electrode 202 and a negative plate or electrode 212 separated by battery separator 220 to electrically isolate electrodes 202 and 212. Positive electrode 202 includes a grid or conductor 206 of a lead alloy material . A positive active material 204, such as lead dioxide, typically coats or is embedded in the grid 206. The grid 206 is also electrically coupled with a positive terminal 208. Grid 206 provides structural support for positive active material 204 as well as electrical conductivity to terminal 208.

Similarly, negative electrode 212 includes a lead-alloy material grid or conductor 216 that is coated or plastered with a negative active material 214, such as lead. The grid 216 is electrically coupled to a negative terminal 218. Like the grid 206, the grid 216 structurally supports the negative active material 214 in addition to providing electrical conductivity to the terminal 218. In lead-acid immersion batteries, the positive electrode 202 and the negative electrode 212 are immersed in an electrolyte (not shown) which may include a solution of sulfuric acid and water. In AGM-type lead-acid batteries, the electrolyte is absorbed and held within the battery separator 220. The battery separator 220 is positioned between the positive electrode 202 and the negative electrode 212 to physically separate the two electrodes while allowing ion transport, thus closing a circuit and allowing an electronic current to flow between the positive terminal 208 and the negative terminal 218. Separator 220 typically includes a microporous membrane (ie, the solid black component), which is often a polymeric film with negligible conductance. The polymeric film can include microscopic-sized voids that allow ion transport (ie, transport of ionic charge carriers) through spacer 220. In one embodiment, the microporous film or polymeric film may have a thickness of 50 microns or less and preferably 25 microns or less, may have a porosity of about 50% or 40% or less, and may have an average pore size of 5 microns or less and preferably 1 micron or less. The polymeric film can include various types of polymers, including polyolefins, polyvinylidene fluoride, polytetrafluoroethylene, polyamide, polyvinyl alcohol, polyester, polyvinyl chloride, nylon, polyethylene terephthalate, and the like. The spacer 220 may also include one or more fiber mats that are located adjacent to one or both sides of the microporous membrane / polymeric film to reinforce the microporous membrane and / or provide puncture resistance.

Positioned near a surface of the negative electrode 212 is a nonwoven fiber mat 230 (referred to herein as a reinforcing mat). The reinforcing mat 230 is partially or fully disposed on the surface of the negative electrode 212 to fully or partially cover the surface. As shown in the

ES 2 622 752 T3

Figures 3A-3C, a reinforcing mat 230 can be disposed on both surfaces of negative electrode 212, or can completely wrap or surround the electrode. Similarly, although the backing mat 230 is shown on the outer surface of the electrode 212, in some embodiments the backing mat 230 may be located on the inner surface of the electrode 212 (ie, adjacent to the spacer 220). The backing mat 230 reinforces the negative electrode 212 and provides an additional support component for the negative active material 214. The additional support provided by the backing mat 230 can help reduce the negative effects of detachment of the negative active material particles. as the active material layer softens due to repeated charge and discharge cycles. This can reduce the degradation commonly experienced from repeated use of lead-acid batteries.

The backing pad 230 is often impregnated or saturated with the negative active material 214 so that the backing pad 230 is partially or fully disposed within the active material layer 214. The impregnation or saturation of the active material within the reinforcing mat imply that the active material penetrates at least partially into the mat. For example, the backing mat 230 may be completely impregnated with the negative active material 214 so that the backing mat 230 is completely buried within the negative active material 214 (ie, completely buried within the lead paste). Fully burying the reinforcing mat 230 within the negative active material 214 means that the mat is fully disposed within the negative active material 214. In one embodiment, the reinforcing mat 230 may be disposed within the negative active material 214 to about a depth X of about 20 mils (i.e., 0.0508 cm (0.020 inches) or 508 pm) from an outer surface of the electrode 212. In other embodiments, glass mat 230 can rest on negative active material 214 so that the mat is impregnated with very little active material. Often the backing mat 230 is impregnated with the negative active material 214 such that the outer surface of the mat forms or is substantially adjacent to the outer surface of the electrode 212 (see backing mat 240). In other words, the active material can fully penetrate through the backing mat 230 such that the outer surface of the electrode 212 is a mixture or mesh of active material and fibers from the backing mat.

As described herein, the reinforcing mat 230 includes multiple glass fibers, an acid resistant binder that bonds the multiple glass fibers together to form the reinforcing mat. The reinforcing mat 230 can have a surface weight of between 10 and 100 g / m² approximately, more frequently between 20 and 60 g / m² approximately. The reinforcing mat 230 can be used to reinforce a lead-acid battery plate or electrode and can include a relatively homogeneous mixture of coarse glass fibers that can include multiple first glass fibers with a diameter of between about 8 and 13 pm. and multiple second fibers with a diameter of at least 6 pm. As used herein, "relatively homogeneous" means that the mixture is at least 85% homogeneous. In some embodiments, the relatively homogeneous mixture may constitute between about 70 and 95% of the mass of the mat 230. In some embodiments, the homogeneous mixture may also include between 5 and 30% conductive fibers. For example, conductive fibers with diameters between about 6 and 8 µm and with lengths between about 8 and 10 mm can be included in the relatively homogeneous mixture. The backing mat 230 also includes an acid resistant binder that bonds the multiple first and second glass fibers together to form the backing mat 230. The backing mat 230 further includes a wetting component that is applied to the backing mat. reinforcement 230 to increase the wettability / absorbency of the reinforcement mat 230. The wettability / absorbency of the backing mat 230 may be increased such that the backing mat 230 has or exhibits a mean water absorption height and / or a mean water / acid solution absorption height of at least 1, 0 cm after exposure to the respective solution for 10 minutes, according to a test carried out according to the ISO 8787 method.

The backing mat 230 may include a conductive material to make the backing mat 230 electrically conductive. For example, a conductive layer can be formed on one or more sides of the backing mat 230 by applying a conductive material to at least one surface of the backing mat 230 or through the backing mat 230. The conductive layer can face and contact electrode 212 to provide an electrical path through which electrons can flow. The conductive material contacts the electrode 212, and more specifically the active material of the electrode 212 to allow the flow of electrons over a surface or through the reinforcing mat 230. The conductive material and / or the backing mat layer 230 may have an electrical resistance of less than about 100,000 ohms per square, and more commonly less than about 50,000 ohms per square, to allow or enhance the flow of electrons over the cell. mat surface 230. In some embodiments, the conductive layer of backing mat 230 may be electrically coupled with a negative terminal 218 to provide a path for current flow to terminal 218.

As described herein, electrons can flow along backing mat 230 or grid / conductor 216, depending on which conductive surface offers an electrical path of least electrical resistance. For example, electrons near terminal 218 may flow along an electrical path of grid / conductor 216, while electrons distant from terminal 218 may flow along an electrical path of backing mat 230 due to an accumulation of lead sulfate on the grid / conductor 216 at the distant location.

ES 2 622 752 T3

In one embodiment, the conductive layer of the reinforcing mat 230 can be formed on a surface of electrically insulating fibers (eg, glass fibers) by coating the conductive material on the insulating fibers or by spraying the conductive material onto the surface of reinforcing mat 230. In a specific example, the conductive material can be added to a primary binder material that is applied to the insulating wet laid fibers to couple the fibers together. The primary binder / conductive material mixture and insulating wet laid fibers can then be cured so that the conductive material completely coats or is saturated along the reinforcing mat 230 to form the conductive layer. In another embodiment, the reinforcing mat 230 can be manufactured in a standard process in which a primary binder without the conductive material is applied to the insulating wet laid fibers to bond the fibers together. The conductive material can then be dispersed in a secondary or diluted binder that is coated or sprayed onto the surface of the reinforcing mat 230. The backing mat 230 can then be cured so that the conductive material forms a conductive layer across the entire surface, or a defined portion, of the backing mat 230. In this embodiment, most of the conductive material can be place on the surface of the reinforcing mat 230.

In another embodiment, a reinforcing mat 230 can be manufactured according to known procedures. A catalyst can then be added to a surface of the backing mat 230 and metal ions, such as copper, can be generated on the surface of the backing mat through the applied catalyst. In yet another embodiment, the conductive material can be added to the reinforcing mat 230 by chemical vapor deposition processes.

In lead-acid battery environments, the conductive material used for the backing mat 230 must be relatively resistant to corrosion due to the aggressive electrochemical environment of the battery. In some embodiments, the conductive material can include a metal, a nanocarbon, graphene, graphite, a conductive polymer (eg, polyanilines), carbon nanocarbons or nanotubes, carbon fibers, copper, titanium oxides, vanadium oxides, oxides tin and the like. In a specific embodiment, the conductive material can include carbon nano-platelets, such as graphene. Graphene can be added to the primary binder or to the secondary / diluted binder as described above and applied to the reinforcing mat 230 (eg, a fiberglass or polyolefin mat) between about 0.01% and 50%. by weight or, in some embodiments, between about 1% and 25% by weight. When cured, the graphene coating forms a conductive layer across the entire surface, or a defined portion, of the reinforcing mat 230.

In another embodiment, the conductive layer may contain a conductive fiber mat, sheet or screen that is positioned adjacent to the surface of the reinforcing mat 230 or entangled with the electrically insulating fibers (eg, glass fibers) of the reinforcing mat 230. In one embodiment, the conductive layer can be made by coating or spraying the conductive fibers onto the surface of the reinforcing mat 230. In another embodiment, a conductive fiber mat may include the multiple conductive fibers arranged in a nonwoven or woven pattern and bonded together by a binder. The conductive fiber mat may be coupled with the reinforcing mat 230 by means of a binder and the like. Electrons can flow along the conductive fiber mat, sheet or screen, as described herein, to the negative terminal 218.

As briefly described above, the reinforcing mat 230 can include multiple electrically insulating fibers, such as glass, polyolefin, polyester, and the like, that are primarily used to reinforce the electrode. Because the backing mat 230 is made of those insulating fibers, the backing mat 230 can be essentially non-conductive prior to or without the addition of the conductive material. For example, without combining or adding the conductive material or layer, the reinforcing mat 230 can have an electrical resistance greater than about 1 Megohm per square. In the manufacture of the reinforcing mat 230, water or other liquid may be removed (eg, through a vacuum) from a suspension of the fibers in the liquid medium. A binder may then be applied to the wet nonwoven glass or polyolefin fibers to form the reinforcing mat 230. As described above, in some embodiments, the conductive material or fibers may be added to the binder and / or or to the liquid medium. In one embodiment, the reinforcing mat 230 may be between about 50 and 500 microns thick and have an average pore size of between about 5 microns and about 5 millimeters.

The backing pad 230 also includes a wetting component that is applied to the backing pad to increase the wettability / absorbency of the backing pad. The wettability / absorbency of the backing mat 230 is increased such that the backing mat has or exhibits a mean water absorption height and / or a mean water / solution absorption height of at least 0.5 cm after of exposure to the respective solution for 10 minutes according to a test carried out according to the ISO 8787 method.

As described herein, the wetting component can be a wettable component of the acid-resistant binder (eg, a hydrophilic functional group), a hydrophilic binder that is mixed with the acid-resistant binder, the wetting component can be component fibers (e.g. cellulose or natural fibers) that are bonded to the glass fibers of the reinforcing mat 230, or the wetting component may be a wettable solution (for example, starch or cellulose solution) that

ES 2 622 752 T3 is applied to the backing mat 230 such that the wettable solution saturates the backing mat 230 or is disposed on at least one surface of the backing mat 230 after drying of the wettable solution. In some embodiments, the wetting component can include a combination of any of the aforementioned components, such as a combination of cellulose fibers and an acid-resistant binder with a wettable component. In a specific embodiment, the glass fibers of the reinforcing mat 230 include first fibers with fiber diameters of between about 6 pm and 30 pm, or between about 8 pm and 12 pm, and the second fibers with fiber diameters of about 10 pm. minus 6 pm approximately.

As described herein, in some embodiments the wetting component can be a wettable component of the acid resistant binder (eg, a hydrophilic functional group) or a hydrophilic binder that mixes / combines with the acid resistant binder. . In other embodiments, the wetting component may be a wettable solution (eg, a starch or cellulose solution) that is applied to the backing pad 230 such that the wetting solution saturates the backing pad 230 or is disposed on the backing pad 230. minus one surface of the backing mat 230 after the wettable solution dries. In yet another embodiment, the wetting component may be a plurality of component fibers (eg, cellulose, cotton, other natural fibers, polyester, other synthetic fibers, or a combination of natural and / or synthetic fibers) that are bonded to the mat. reinforcement 230. According to one embodiment, the component fibers may form a mat of component fibers that are bonded to at least one side of the glass reinforcing mat 230 such that the reinforcing mat 230 includes a two-layer mat configuration. In another embodiment, the component fibers may be mixed with the glass fibers such that in forming the glass mat the component fibers entangle and bond with the glass fibers. In other embodiments, the wetting component can be a combination of the wetting components described above (ie, a binder with a wettable component, a wettable solution, and / or a fiber component).

Referring now to Figures 3A-C, various electrode reinforcing mat configurations are illustrated. Figure 3A illustrates a configuration in which an electrode 300 has a single reinforcing mat 302 disposed at or near an outer surface. As described above, the backing mat 302 may include a conductive material and / or layer so as to allow the flow of electrons over a surface and / or through the backing mat 302 to a battery terminal. The backing pad 302 may also include a wetting component as described above to improve the wettability properties of the pad 302. The backing mat 302 may partially or fully cover the outer surface of the electrode 300. The configuration of Figure 3B is similar to that of Figure 3A, except that an additional backing mat 304 is disposed on or near an opposite surface of the electrode. electrode 300 such that electrode 300 is sandwiched between the two glass mats 302 and 304. Either or both of the backing mats 302 and 304 may include a conductive material and / or layer to allow the flow of electrons to a battery terminal as well as a wetting component. As such, the electrode 300 may be sandwiched between two conductive backing mats 302 and 304. Figure 3C illustrates a configuration in which a backing mat 306 wraps or surrounds the electrode 300. Although Figure 3C illustrates the reinforcing mat 306 completely enveloping the electrode 300, in many embodiments an upper side of the mat 306, or a portion thereof, is open. The glass mat 306 may include the conductive material and / or layer as described above to allow the flow of electrons, as well as a wetting component.

Referring again to Figures 1 and 2, a backing pad 240 is located near a surface of the positive electrode 202. The backing pad 240 may be arranged and / or coupled with a positive electrode 202 in a similar manner to the arrangement. and engagement of the reinforcing mat 230 with respect to the negative electrode 212. For example, the backing mat 240 may be partially or fully disposed on the surface of the positive electrode 202 to partially or fully cover the surface, it may be located on an interior surface of the electrode 202 (i.e., adjacent to the spacer 220) instead. of the configuration shown on the outer surface, and / or may be impregnated or saturated with positive active material 204 such that reinforcing mat 240 is partially or fully disposed within active material layer 204. Like reinforcing mat 230, reinforcing mat 240 It also provides additional support to help reduce the negative effects of shedding of positive active material particles due to repeated charge and discharge cycles.

In some embodiments, the backing mat 240 may include a conductive / conductive material and / or layer to allow the flow of electrons over a surface and / or through the backing mat 240 to the positive terminal 208. In such embodiments, Electrons can flow either through backing mat 240 or through grid / conductor 206, depending on which conductive surface provides an electrical path of least electrical resistance. For example, electrons near positive terminal 208 can flow along an electrical path of grid / conductor 206, while electrons away from terminal 208 can flow along an electrical path of backing mat 240. In some embodiments both the backing mat 230 and the backing mat 240 can both include a conductive material and / or conductive layer to allow electron flow over or relative to both mats. Both the backing pad 230 and backing pad 240 can both include a wetting component, as described herein.

ES 2 622 752 T3

With respect to the reinforcing functions of the reinforcing mats 230 and / or 240, in some embodiments the reinforcing aspects of these mats can be enhanced by mixing fibers having different fiber diameters. The reinforcing mats 230 and 240 (hereinafter referred to as the reinforcing mat 230) may have similar characteristics and compositions, and may include a mixture of two or more coarse fibers of different diameters. In one embodiment, the reinforcing mat 230 includes multiple first coarse fibers, having fiber diameters in the range between about 6 pm and about 13 pm, between about 6 pm and 11 pm, or between about 8 pm and about 13 pm. The first coarse fibers are mixed with multiple second coarse fibers, having fiber diameters of at least about 6 pm, preferably between 6 pm and 7 pm. In some embodiments, the multiple coarse second fibers may include a silane material size. The mixture of coarse fibers of two or more different diameters results in a mat that is strong enough to structurally support the active material, as described above, and to withstand the various manufacturing processes of the plate, while being it also minimizes the overall thickness and size of the mat. It may be desirable to reduce the thickness of the backing mat 230 while maintaining the strength of the mat, because the backing mat 230 is typically a chemically inactive component, and therefore does not contribute to the electrochemical process of the battery. Reducing the volume of the backing mat 230 helps to minimize the volume of battery components that do not contribute electrochemically.

In one embodiment the reinforcing mat 230 may include a mixture of between 10% and 95% of the first coarse fibers and between 5% and 80% of the second coarse fibers. In another embodiment, the reinforcing mat 230 may include a blend of between 70% and 95% of the first coarse fibers and between 5% and 30% of the second coarse fibers. In another embodiment, the reinforcing mat 230 may include a blend of between 40% and 90% of the first coarse fibers and between 5% and 30% of the second coarse fibers. In another embodiment, the reinforcing mat 230 may include a blend of between 10% and 20% of the first coarse fibers and between 60% and 80% of the second coarse fibers. In yet another embodiment, the mixture of the first thick fibers and the second thick fibers is approximately equal (ie, 50% of the first and second thick fibers).

The length of the coarse fibers can also contribute to the overall strength of the reinforcing mat 230, by physically entangling with adjacent fibers or fiber bundles and / or creating additional contact points at which separate fibers are joined by a binder. In one embodiment the first and second coarse fibers have fiber lengths in the range of about 1/3 inch to about 1¹Z inch), although an upper limit of length of about 3.18 cm (1 1/4 inch) (1 inch = 2.54 cm) is more common. This range of lengths provides sufficient strength to the mat while allowing the fibers to disperse in a clear water solution for mat treatment applications. In another embodiment the first and second coarse fibers may have fiber lengths in the range of 1.27 (1/2 inch) to 1.91 cm (3/4 inch). The fiber lengths of the first coarse fibers may be different from the fiber lengths of the second coarse fibers. For example, in one embodiment, the first fibers may have an average fiber length of approximately 1/3 inch, while the second coarse fibers have an average fiber length of approximately 1.9 cm (3 / 4 inch). The fiber lengths of the first coarse fibers may be different from the fiber lengths of the second coarse fibers. For example, in one embodiment, the first fibers may have an average fiber length of approximately 1/3 inch, while the second coarse fibers have an average fiber length of approximately 1.9 cm (3 / 4 inch). In one embodiment, either or both of the first and second coarse fibers have an average fiber length of at least 1/3 inch, while in another embodiment, either of the first and second coarse fibers, or both have an average fiber length of at least 1/2 inch.

The type and amount of binder used to bond the first and second coarse fibers together can also contribute to the overall strength and thickness of the reinforcing mat 230. As described above, the binder is generally an acid resistant and / or chemically resistant binder that provides the durability to withstand the acidic environment throughout the life of the battery, the strength to withstand the additive operation. the paste on the plate, and the permeability to allow penetration of the paste. For example, the binder can be an acrylic binder, a melamine binder, a UF binder, or the like. The binder can also include and bond the conductive material to the first and / or second coarse fibers. Increased use of binder can reduce the thickness of the reinforcing mat 230 by creating more interfiber bonds and densifying the reinforcing mat 230. Increased interfiber bonds can also increase the strength of the reinforcing mat 230. In one embodiment, the binder is applied to the first and second coarse fibers such that the binder makes up between about 5% and 45% by weight of the reinforcing mat 230 or between about 15% and 35% by weight of the mat. reinforcement. In another embodiment, the binder is applied to the first and second coarse fibers in such a way that it accounts for between about 5% and about 30% by weight of the reinforcing mat 230.

As described herein, the conductive material can be mixed with the binder or a secondary binder and applied to the first and / or second coarse fibers during or following the manufacture of the reinforcing mat 230. For example, the binder can include conductive fibers (eg carbon fibers) and / or other conductive material (eg graphite). In some embodiments the binder can include between about 5-30% graphite particles. The resulting reinforcing mat 230 may have

ES 2 622 752 T3 an electrical resistance of less than 100,000 ohms per square, and more commonly less than 50,000 ohms per square, to allow the flow of electrons over a surface of, or through, the reinforcing mat.

The wetting component can be mixed with the binder in some embodiments. The resulting reinforcing mat 230 may have or have an average water absorption height of at least 0.5 cm after exposure to water for 10 minutes, performed according to the ISO 8787 method. The wetting component is soluble in an acid solution of the lead-acid battery, whereby a significant part of the nonwoven fiber mat is lost due to dissolution of the wetting component. For example, approximately 5-85% of the reinforcing mat 230 may be lost.

The above-described configurations of the reinforcing mat 230 provide mats having an overall tensile strength of at least 13.62 kg / 7.62 cm (30 pounds / 3 inches) and more commonly 15.89 kg / 7. , 62 cm (35 pounds / 3 inches). Specifically, the reinforcing mat 230 has a machine direction tensile strength of at least 9.99 kg / 7.62 cm (22 pounds / 3 inches) and a cross machine direction tensile strength of at least 5.90 kg / 7.62 cm (13 pounds / 3 inches). The mats described above have been found to have sufficient strength to support the active material and to withstand the various stresses imposed during manufacturing and processing (eg application of the paste or active material) of the plate or electrode. A reinforcing mat 230 that does not have the tensile strength attributes described above may not be strong enough to support the applied active material (for example, prevent shedding and the like) and / or may pose processing problems, such as mat breakage when applying the active material paste (eg lead or lead oxide) on the glass mat during the plate reinforcement process.

In addition, the configuration of the reinforcing mat 230 described above provides mats having a thickness of 0.0254 cm or less (10 thousandths (ie, 0.010 inches) of an inch or less) and, more commonly, 0.02286. cm or less (9 thousandths of an inch (0.009 inches) or less). In one embodiment, the reinforcing mat 230 has a thickness in the range of about 0.01524 cm to 0.02032 cm (6 to 8 thousandths of an inch (i.e., 0.006 inches to 0.008 inches), and preferably about 0.01778 cm (7 mils (0.007 inches). These mats take up minimal space within the electrode and inside the battery, allowing additional electrochemically active materials (for example, additional electrolyte and / or lead or lead oxide paste) to be included in the battery, thereby increasing service life and the efficiency of the battery. The mats described above exhibit the unique combination of minimum size or thickness and strength, while being electrically conductive. The mats can also have a pore size in the range between 50 microns and 5 mm.

In some embodiments, spacer 220 may have a similar composition to backing mat 230 and may be particularly useful in AGM batteries. For example, spacer 220 can be made of glass fibers, or various polymers, such as polyethylene, polypropylene, and the like. In some embodiments, spacer 220 can include nonwoven fibers. The spacer 220 can be a nonwoven fiber mat. In some embodiments, a reinforcing mat 250 may be located adjacent to spacer 220. Spacer 220 may have a surface weight of between 100 and 400 g / m2.², approximately. Most often, the separator 220 has a surface weight between 150 and 300 g / m², approximately. The spacer 220 can be a mat formed from a combination of coarse glass fibers. For example, separator 220 may include a mixture of about 10-20% of multiple first glass fibers with diameters of about 8-13 µm and about 60-80% of multiple second glass fibers with diameters of at least 6 pm. The multiple second glass fibers may include a silane material size. The spacer 220 may further include an acid resistant binder that binds the first multiple glass fibers and the second multiple glass fibers together to form the spacer 220. The binder can be an acrylic binder, a melamine binder, a UF binder, or Similary. In some embodiments, separator 220 can include between about 70 and 95% of the coarse glass fiber blend. In some embodiments, spacer 220 can include 5 to 30% of an acrylic binder.

In some embodiments, the backing mat 250 may also include a conductive material and / or layer to allow the flow of electrons over a surface and / or through the backing mat 250 to the positive terminal 208 and / or the negative terminal. 218. For example, the fiber mat or reinforcing mats 250 may include a conductive material and / or a conductive layer, for example contained in the mat binder, as a conductive fiber film, mat, or layer, and / or as any embodiment described herein. For example, the binder can include conductive fibers (eg, carbon fibers) and / or other conductive materials (eg, graphite). In such embodiments, electrons can flow along backing mat 230, grid / conductor 216, backing mat 240, grid / conductor 206, spacer 220, and / or backing mat 250, depending on which conductive pathway offers the least. electric resistance. For example, electrons near grid / conductor 216 may flow along grid / conductor 216 and / or backing mat 230 to terminal 218, while electrons near separator 220 flow along a pathway. from separator 220 to terminal 218. Similarly, electrons near grid / conductor 206 can flow along grid / conductor 206 and / or backing mat 240 to terminal 208, while electrons near spacer 220 flow along of an electrical path from separator 220 to terminal 208. In such embodiments, the number of available paths can be greatly increased or

ES 2 622 752 T3 possible for electrons. In embodiments where the spacer includes conductive materials, there is a non-conductive layer and / or other non-conductive nonwoven mat positioned against the conductive portion of the spacer. In embodiments that do not use another non-conductive nonwoven mat, the conductive material in the spacer may be located on or near a surface of the spacer such that at least one non-conductive layer extends through a center of the spacer.

In some embodiments, the backing mat 250 may further include a wetting component. For example, the reinforcing mat 250 may include 10 to 40% cotton fibers, such as cotton microfibers with diameters between about 0.5 and 3.0 µm. The wetting component can increase the wettability / absorbency of the backing pad 250 such that the backing pad 250 has or exhibits a medium water absorption height and / or a medium water / acid solution absorption height. of at least 1.0 cm after exposure for 10 minutes to the respective solution, according to a test carried out according to the ISO 8787 method.

Procedures and methods

Referring now to FIG. 4, a method 400 for manufacturing an electrode is illustrated. The process may involve transporting a lead alloy grid 410 on a conveyor to an active material applicator 430 (e.g., lead paste or lead oxide applicator), which applies or bonds the active material 430 to the grid 410. A coil 420 of nonwoven mat can be positioned below the grid 410 so that a reinforcing mat is applied to the lower surface of the grid 410. The reinforcing mat may include a conductive material and / or conductive layer, as well as a humectant component, as described herein. In some embodiments, the reinforcing mat may also include a coarse fiber blend as described herein. In some embodiments, the reinforcing mat can also include a mixture of coarse glass fibers and glass microfibers, in addition to the wetting component as described herein. A second coil 440 of nonwoven mat may be positioned above the grid 410 so that a second reinforcing mat is applied to an upper surface of the grid 410. The second reinforcing mat may also include a conductive material, a wetting component, and / or layer and / or blend of coarse fibers and / or microfibers (similar to or different from that of the reinforcing mat 420). The resulting electrode or plate 450 can be subsequently cut to length by means of a plate cutter (not shown). As described herein, the active material 430 can be applied to the grid 410 and / or the top and bottom of the reinforcing mats, 440 and 420, such that the active material impregnates or saturates the mats at a rate. desired grade. The electrode or plate 450 can then be dried by means of a drier (not illustrated) or another component of process 400. As described herein, the backing mats 440 and 420 can assist in drying the electrode or plate 450 by absorbing the water and / or the water / acid solution from the electrode or plate 450 to allow water and / or or the water / acid solution evaporates.

Referring now to FIG. 5, a lead acid battery plate manufacturing method 500 is shown. In block 510, a grid of lead alloy material is provided. The lead alloy material grid may be for a positive electrode (eg grid / lead 206) or for a negative electrode (eg grid / lead 216) of a battery. At block 520, a paste of active material is applied to the lead alloy material grid to form a battery plate or electrode (ie, negative or positive electrode). At block 530, a nonwoven fiber mat is applied to a surface of the active material pulp such that the nonwoven fiber mat is at least partially disposed within the active material pulp. As described herein, the nonwoven fiber mat may include multiple fibers, a binder material that bonds the multiple fibers together, a wetting component, and a conductive material disposed at least partially within the nonwoven fiber mat to get in contact with the active material paste. The wetting component can provide absorbency to allow complete wetting of the electrodes of a lead-acid battery. The conductive material can be any material described herein and / or a conductive layer that is formed on the nonwoven fiber mat. The nonwoven fiber mat can offer an electrical resistance of less than about 100,000 ohms per square to allow the flow of electrons over a surface of the nonwoven fiber mat. In some embodiments, the nonwoven fiber mat may be disposed within the active material pulp between about 0.00254 cm (0.001 inch) and 0.0508 cm (0.020 inch).

In some embodiments, the method may also include applying a second nonwoven fiber mat to an opposite surface of the active material paste such that the lead alloy material mat is disposed between the two nonwoven fiber mats. The second nonwoven fiber mat may also contain a conductive material that is disposed at least partially within the second nonwoven fiber mat to be in contact with the active material pulp. In some embodiments, the nonwoven fiber mat may have a thickness of 0.02286 cm (0.009 inches) or less and / or a tensile strength of at least 13.5 Kg / 7.62 cm (30 pounds / 3 inches).

In some embodiments, the multiple fibers can include a mixture of coarse fibers as described above. For example, the multiple fibers may include first fibers with fiber diameters of between about 8 pm and about 13 pm and second fibers with fiber diameters of at least about 6 pm. In some embodiments, the binder can include the conductive material. The binder is

ES 2 622 752 T3 can apply to the mat between 5% and 45% by weight approximately, between 20% and 30% by weight approximately, and the like. In some embodiments, the conductive material may include multiple conductive fibers that are entangled with fibers from the nonwoven fiber mat.

Referring now to FIG. 6, an embodiment of a method 600 of manufacturing a nonwoven fiber mat for reinforcing a lead-acid battery plate or electrode (hereinafter reinforcing mat) is illustrated. The method described herein can be used to produce backing mats for both lead-acid immersion batteries and separators in AGM batteries. In block 610, multiple glass fibers are provided. Glass fibers can be coarse fibers, microfibers, or a combination of coarse fibers and microfibers. At block 620, an acid resistant binder is applied to the multiple glass fibers to bond the multiple glass fibers together to form the reinforcing mat. At block 630, a wetting component is added to the glass fibers and / or the backing mat to increase the wettability / absorbency of the backing mat. As described herein, the wetting / absorbing capacity of the backing pad can be increased such that the backing pad has or exhibits a medium water absorption height and / or a medium absorption height of a solution. of water / acid of at least 0.5 cm after exposure for 10 minutes to the respective solution according to the test carried out according to the ISO 8787 method. A conductive material may be applied to the glass fibers and / or the reinforcing mat of block 640. Application of the conductive material may include providing a layer of conductive fibers and / or other conductive materials and placing this layer on top of the mat of glass. The conductive material can also include a coating that is applied to the mat. In some embodiments, the conductive material can be added to a binder that is applied to the fiber mat. In other embodiments, the conductive material may include conductive fibers that are at least partially disposed within, and / or entangled with, the fiber mat.

In some embodiments, application of the wetting component includes applying the acid-resistant binder, where the acid-resistant binder includes a conductive material and / or a wettable component (eg, a hydrophilic functional group, a strong hydrophilic binder mixture to acids, and the like) which functions to increase the wettability / absorbency of the nonwoven fiber mat. In another embodiment, the application of the wetting component includes applying a wettable solution (eg, cellulose starch solution and the like) to the backing pad such that the wetting solution saturates the backing pad or is disposed on at least a surface of the reinforcing mat after drying of the wettable solution.

In yet another embodiment, the application of the wetting component includes bonding multiple component fibers (eg, cellulose fibers and the like) to the multiple glass fibers of the reinforcing mat. In such embodiments, the reinforcing mat may include about 40-95% of the glass fibers and up to 50% of the cellulose fibers, and more commonly about 10-40% of the cellulose fibers. In a specific embodiment, the reinforcing mat can include between about 60 and 80% of the glass fibers and between 10 and 40% of the cellulose fibers. In still other embodiments, the application of the wetting component may include the application of any combination of the wetting components described herein, such as the component fibers, the wettable solution, and / or the acid-resistant binder having a wettable component. .

In some embodiments, the multiple glass fibers may include first glass fibers with fiber diameters between about 8 pm and about 30 pm. In such embodiments, the method 600 may further include providing multiple second glass fibers with fiber diameters between about 0.01 pm and about 5 pm and bonding the multiple second glass fibers to the first glass fibers using the acid resistant binder. . The addition of the second glass fibers can increase the wettability / absorption capacity of the reinforcing mat so that the reinforcing mat has a medium water absorption height and / or a medium absorption height of a water / solution. acid of at least 1.0 cm after exposure for 10 minutes to the respective solution according to the test carried out according to the ISO 8787 method. In some embodiments, the component fibers (eg, cellulose fibers and the like) can be bonded to the multiple first glass fibers and the multiple second glass fibers. In such embodiments, the reinforcing mat may include between about 40 and 80% of the first glass fibers, between 10 and 50% of the second glass fibers, and between 5 and 40% of the cellulose fibers. In another embodiment, the reinforcing mat may include about 40 to 50% of the first glass fibers, 20% to 30% of the second glass fibers, and 20% to 30% of the cellulose fibers.

Examples (The examples in Tables 1 and 2 do not form part of the present invention).

Two reinforcing mats were prepared according to the embodiments described herein. The strength of the mats was measured. The following are the mat manufacturing methods and results.

ES 2 622 752 T3

1. Reinforcing structure using graphene as a conductive coating

To produce the conductive graphene coating, a suspension mixture was prepared using graphene (xGnP-M-15 from XG Sciences) and an acrylic binder (RHOPLEX ™ HA-16 from Dow Chemical). The suspension mixture was prepared so that it contained approximately 0.5% binder and 1.5% graphene. A spray gun was then used to apply the mixture to a glass mat (Dura-Glass® PR-9 and B10 mat). The mat was then dried at 125 ° C for about 1 hour and cured at 175 ° C for about 3 minutes. The surface resistance was then measured and the results are provided in Table 1 below.

Table 1: Reinforced mat using graphene as conductive coating

<td>Show</td><td>Endurance superficial (ΚΩ)</td><td>Sample length (cm)</td><td>Sample width (cm)</td><td>Resistivity superficial (ΚΩ / square)</td><td>Weight before coating (g)</td><td>Graphene (%)</td>

<td>B-10 (1)</td><td> 1,84</td><td> 14,3</td><td> 12,2</td><td> 1,6</td><td> 0,7609</td><td> 15,8%</td>

<td>B-10 (2)</td><td> 3,41</td><td> 14,2</td><td> 12,2</td><td> 2,9</td><td> 0,7643</td><td> 14,5%</td>

<td>B-10 (3)</td><td> 2,25</td><td> 14,2</td><td> 11,9</td><td> 1,9</td><td> 0,7334</td><td> 17,3%</td>

<td>PR-9 (1)</td><td> 13,76</td><td> 14,2</td><td> 12</td><td> 11,6</td><td> 0,4577</td><td> 10,1%</td>

<td>PR-9 (2)</td><td> 18,26</td><td> 14,2</td><td> 12,3</td><td> 15,8</td><td> 0,4651</td><td> 11,7%</td>

<td>PR-9 (3)</td><td> 5,29</td><td> 14,7</td><td> 12,2</td><td> 4,4</td><td> 0,4728</td><td> 8,9%</td>

Using the graphene material, no significant coating weight loss was shown after a standard acid test (40% by weight sulfuric acid, 70 ° C for 72 hours). As such, graphene-coated glass mats experience weight loss similar to uncoated glass mats. However, a slight drop in conductivity was observed after exposure of the mat to sulfuric acid for a long time. This slight drop in conductivity can indicate the reaction between graphene and sulfuric acid.

two. Reinforcing mat using CNS (Carbon Nanostructure) as conductive coating

To produce the CNS conductive coating, a suspension mix was prepared using CNS (from Applied Nanostructured Solutions LLC) and / or an acrylic binder (RHOPLEX ™ HA-16 from Dow Chemical). The suspension mixture was prepared so that it contained approximately 1% binder (or no binder) and 0.5% CNS. A glass mat (Dura-Glass® PR-9 mat or polyester spun-bonded mat, uncoated) was placed in the mixture and the water was aspirated under vacuum. A uniform coating of the CNS was obtained. The mat was then dried at 125 ° C for about 1 hour and cured at 175 ° C for about 3 minutes. The surface resistance was then measured and the results are provided in Table 2 below.

Table 2: Reinforced mat using CNS (Carbon Nanostructure) as conductive coating

<td>Show</td><td>Endurance superficial (Ω)</td><td>Sample length (cm) (inch)</td><td>Sample width (cm) (inch)</td><td>Resistivity superficial (Ω / square)</td><td>CNS%</td><td>Commentary</td>

<td>PR-9 (1)</td><td> 180</td><td> 35,56 (14)</td><td> 30,48 (12)</td><td> 154,3</td><td> 2.50%</td><td>with binder</td>

<td>PR-9 (2)</td><td> 65</td><td> 35,56 (14)</td><td> 35,56 (14)</td><td> 65,0</td><td> 15%</td><td>without binder</td>

<td>PR-9 (3)</td><td> 53</td><td> 35,56 (14)</td><td> 35,56 (14)</td><td> 53,0</td><td> 25%</td><td>with binder</td>

<td>PR-9 (4)</td><td> 50</td><td> 35,56 (14)</td><td> 35,56 (14)</td><td> 50,0</td><td> 15%</td><td>without binder</td>

<td>PR-9 (5)</td><td> 66</td><td> 35,56 (14)</td><td> 35,56 (14)</td><td> 66,0</td><td> 25%</td><td>without binder</td>

<td>Polyester (1)</td><td> 239</td><td> 34,29 (13,5)</td><td> 34,29 (13,5)</td><td> 239,0</td><td> 0.3%</td><td>with binder</td>

<td>Polyester (2)</td><td> 68</td><td> 34,29 (13,5)</td><td> 34,29 (13,5)</td><td> 68,0</td><td> 2%</td><td>with binder</td>

<td>Polyester (3)</td><td> 132</td><td> 34,29 (13,5)</td><td> 34,29 (13,5)</td><td> 132,0</td><td> 0.66%</td><td>with binder</td>

By using the CNS material, no significant coating weight loss was shown or experienced after an acid standard test (40% by weight sulfuric acid, 70 ° C for 72 hours). As such, CNS-coated glass mats experience weight loss similar to non-glass mats.

ES 2 622 752 T3 coated. Furthermore, no significant drop in conductivity was observed after the mat was exposed to sulfuric acid for a long time. It is believed that since the CNS has the structure of a cross-linked matrix of carbon nanotubes, although the sulfuric acid attacks some carbon, the entire structure remains connected and therefore the conductivity of the coating is not affected. Given these results, CNS may be a better choice as a conductive coating than graphene. Additionally, the CNS coating provides much better conductivity (ie less resistance) than graphene in non-woven mats. For example, as shown in Table 1, kilo ohms are used as units to express graphene resistance, while in Table 2, ohms are used as units for CNS resistance.

Various reinforcing mats were manufactured in accordance with the embodiments described herein and tested for the wettability / absorbency of the mats. The wettability / absorbency tests were performed according to the ISO 8787 method. The mats were exposed to both a water solution and a water / acid solution, where the sulfuric acid concentration was approximately 40%. The results of the tests are shown in Table 3 below.

Table 3: Sample of reinforced mat

<td>ID. shows</td><td>Sample description</td><td>Binder</td><td>Average water absorption height after 10 minutes (cm)</td><td>Dev. standard</td><td>Average acid absorption height (40%) after 10 minutes (cm)</td><td>Dev. standard</td>

<td>Control</td><td>100% thick glass fibers</td><td>RHOPLEX ™ HA-16</td><td> 0,0</td><td> 0</td><td> 0,0</td><td> 0,0</td>

<td> 1</td><td>50% glass fibers 1.9 cm K249 T, 50% cellulose</td><td>RHOPLEX ™ HA-16</td><td> 0,8</td><td> 0,15</td><td> 1,2</td><td> 0,12</td>

<td> 2</td><td>50% glass fibers 1.9 cm K249 T, 50% cellulose</td><td>Hycar® FF 26903</td><td> 0,9</td><td> 0,15</td><td> 0,9</td><td> 0,15</td>

<td> 3</td><td>50% glass fibers 1.9 cm K249 T, 25% cellulose, 25% 206-253</td><td>Hycar® FF 26903</td><td> 2,7</td><td> 0,05</td><td> 1,9</td><td> 0,25</td>

<td colspan="7">A control mat was also manufactured and tested to provide a point of comparison or benchmark for the other mats tested. The control mat includes 100% coarse glass fibers (T glass fibers) with an average fiber length of approximately 3/4 inch (1.9 cm) and an average fiber diameter</td>

from approximately 1 pm. The glass fibers were bonded together with an acid-resistant binder sold by Dow Chemical under the trade name RHOPLEX ™ HA 16. The acid-resistant binder was applied so as to have a Loss on Ignition (LOI) of approximately twenty%. The control mat showed a mean water absorption height and a mean acid absorption height of approximately 0.0 cm after exposure to the respective solutions for 10 minutes. In other words, the control mat showed essentially no wettability / absorbency.

A first mat (i.e. Sample ID 1) was manufactured that included about 50% coarse glass fibers with a mean fiber length of about 3/4 inch and a mean fiber diameter of about 13 pm, and which included 50% cellulose fibers with an average fiber length of about 2.40 mm. Cellulose fibers were made from a pulp suspension by pre-soaking a Kraft board in water (e.g. Kamloops Chinook Kraft board made by Domtar) and agitating the water-soaked Kraft board for at least 10 minutes. The cellulose fiber pulp slurry was then combined with the glass fibers. The coarse glass fibers and cellulose fibers were bonded together with RHOPLEX ™ HA-16 binder so that they had a LOI of approximately 20%. The first mat showed a mean water absorption height of about 0.8 cm, with a standard deviation of 0.15 after exposure to the aqueous solution for 10 minutes. The first mat also showed a mean water / acid absorption height of about 1.2 cm, with a standard deviation of 0.12 after exposure to the water / acid solution for 10 minutes.

A second mat (ie Sample ID 2) was made with approximately 50% coarse glass fibers and 50% cellulose fibers having similar fiber properties as the first mat. The fibers of

ES 2 622 752 T3 coarse glass and cellulose fibers were bonded together with an acid resistant binder sold by Lubrizol under the trade name Hycar® FF 26903. The binder was applied so as to have an LOI of about 20%. The second mat showed a mean water absorption height of about 0.9 cm, with a standard deviation of 0.15 after exposure to the aqueous solution for 10 minutes. The second mat also showed a mean water / acid solution absorption height of about 0.9 cm, with a standard deviation of 0.15 after exposure to the water / acid solution for 10 minutes.

A third mat (ie Sample ID 3) was manufactured that included approximately 50% coarse glass fibers and 25% cellulose fibers with fiber properties similar to the first and second mats. The third mat also included about 25% glass microfibers with a mean fiber diameter of about 0.76 µm (ie, Johns Manville 206-253 fibers). Coarse glass fibers, glass microfibers, and cellulose fibers were bonded together with Hycar® FF 26903 binder so that they had a LOI of approximately 20%. The third mat showed a mean water absorption height of approximately 2.7 cm with a standard deviation of 0.05 after exposure to the aqueous solution for 10 minutes. The third mat also showed a mean water / acid solution absorption height of approximately 1.9 cm with a standard deviation of 0.25 after exposure to the water / acid solution for 10 minutes.

As shown in the above test results, the addition of the wetting component to the backing mat, which in this case included cellulose fibers, significantly increased the wettability / absorbency of the backing mat. Furthermore, the inclusion of glass microfibers in the backing mat along with the wetting component significantly increased the wettability / absorbency of the backing pad beyond that shown by adding the wetting component alone.

Having described various embodiments, those skilled in the art will recognize that various modifications, alternative constructions, and equivalents can be used without departing from the scope of the invention. Furthermore, a number of well-known processes and elements have not been described in order to avoid unnecessarily obscuring the present invention. Therefore, the above description should not be considered as limiting the scope of the invention.

When a range of values ​​is provided, it will be understood that each intermediate value, up to the tenth of the unit of the lower limit unless the context clearly indicates otherwise, between the upper and lower limits of that range, is also specifically included. Each smallest interval between any indicated value or intermediate value in a set interval and any other indicated or intermediate value in a set interval is included. The upper and lower limits of these smaller ranges may be independently included or excluded in the range, and each range in which either, neither, or both limits are included in the smaller ranges is also included within the invention, subject to any limit. specifically excluded in the established interval. When the indicated range includes one or both limits, the ranges that exclude either or both of the included limits are also included.

As used herein and in the appended claims, the singular forms a, an, the, and "the" include plural referents, unless the context clearly indicates otherwise. Thus, for example, reference to a process includes multiple processes and reference to device includes reference to one or more devices and equivalents thereof known to those skilled in the art, and so on.

Likewise, the words comprise, comprising, including and including and "includes", when used in this specification and in the following claims, are intended to specify the presence of features, integers, components or steps, but do not preclude the presence or addition of one or more characteristics, integers, components, steps, acts, or groups.