WO2021067774A1

WO2021067774A1 - Spiral wound battery & cell with carbonised fiber mat current collector

Info

Publication number: WO2021067774A1
Application number: PCT/US2020/054035
Authority: WO
Inventors: Matthew A. Spence; Deepan C. Bose
Original assignee: Cps Technology Holdings Llc
Priority date: 2019-10-04
Filing date: 2020-10-02
Publication date: 2021-04-08

Abstract

A lead-acid battery is disclosed. The lead-acid battery comprises a container with a cover and one or more compartments. One or more spiral wound cell elements are provided in the one or more compartments. The spiral wound cell elements comprise a positive electrode and a negative electrode. The positive electrode has a positive current collector and a positive electrochemically active material in contact therewith. The negative electrode has a negative current collector and a negative electrochemically active material in contact therewith. At least one of the positive electrode or the negative electrode comprises a carbonized fiber mat current collector impregnated with electrochemically active material. Electrolyte is provided within the container. One or more terminal posts extend from the container or the cover and are electrically coupled to the one or more cell elements. A spiral wound battery cell is also disclosed.

Description

SPIRAL WOUND BATTERY & CELL WITH CARBONISED FIBER MAT CURRENT COLLECTOR

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to United States Provisional Patent Application, Serial No. 62/910,629 filed October 4, 2019, entitled “SPIRAL WOUND BATTERY WITH OXIDIZED CARBON FIBER FELT SUBSTRATE”, the entire contents of which is hereby incorporated by reference herein in its entirety.

BACKGROUND

[0002] The present disclosure relates to the field of batteries. The present disclosure more specifically relates to the field of lead-acid batteries.

[0003] Lead-acid batteries are known. Lead-acid batteries are made up of plates of lead and separate plates of lead dioxide, which are submerged into an electrolyte solution. The lead, lead dioxide and electrolyte provide a chemical means of storing electrical energy which can perform useful work when the terminals of the battery are connected to an external circuit. The plates of lead, lead dioxide and electrolyte, together with a battery separator, are contained within a housing of a polypropylene material.

[0004] One type of lead-acid battery is an AGM or absorbent glass mat lead-acid battery which is a sealed (e.g., maintenance- free), or more specifically a valve regulated battery, in which the electrolyte is absorbed and retained in a mat that is wrapped around or interleaved with an electrode(s) or plate(s). AGM lead-acid batteries are recombinant batteries, that is, ¾ and O2 generated during charging are recombined to water in the battery. AGM lead-acid batteries are advantageous over traditional starting, lighting and ignition (SLI) batteries, in that they are better suited to provide power in a vehicle with numerous electronic features or plug-in accessories. AGM batteries are also a preferred solution for fuel saving start-stop vehicle technology.

[0005] Another type of lead-acid battery is a battery having one or more battery cell elements in a wound configuration (e.g., spiral wound or jelly roll) that may be used for flooded SLI, AGM, and other applications.

[0006] Start-stop vehicles can place various demands on a battery. Vehicles also are increasing in the electrical load of components, for which the electrical load must be supported through a stop event. Vehicle manufacturers are seeking a cost effective, reliable energy storage solution that ensures a seamless customer experience. Therefore there is a need for consistent reliable performance from a lead-acid battery. There is also a need for a robust battery which can support additional prolonged/intermittent loads and support optimal duration and frequency of stop events. To this end, a need exists for a lead-acid battery which provides sustainable and fast rechargeability (e.g., optimized charge acceptance) and consistent cycling performance. Accordingly, a need exists for a lead-acid battery with improved performance over existing devices.

SUMMARY

[0007] A lead-acid storage battery and an absorbent glass mat lead-acid storage battery are disclosed which have improved performance over existing devices.

[0008] The lead-acid battery has a container with a cover and includes one or more compartments. One or more cell elements are provided in the one or more compartments. The one or more cell elements comprise a positive electrode, the positive electrode having a positive current collector and a positive electrochemically active material in contact with the positive current collector; a negative electrode, the negative electrode having a negative current collector and a negative electrochemically active material in contact with the negative current collector. In one or more examples, the one or more battery cell elements are provided in a wound configuration (e.g., spiral wound or jelly roll). A separator may also be provided. In one or more examples, the separator is an absorbent glass mat. Electrolyte is provided within the container. One or more terminal posts extend from the container or the cover and are electrically coupled to the one or more cell elements. At least one electrode, such as for example the positive electrode, may comprise, in lieu of a punched, cast, or expanded metal grid, for example, an oxidized carbon fiber or carbonized fiber mat. The oxidized carbon fiber or carbonized fiber mat may be impregnated with a paste.

[0009] An additional lead-acid battery is disclosed. The lead-acid battery comprises a container with a cover and one or more compartments. One or more spiral wound cell elements are provided in the one or more compartments. The spiral wound cell elements comprise a positive electrode and a negative electrode. The positive electrode has a positive current collector and a positive electrochemically active material in contact therewith. The negative electrode has a negative current collector and a negative electrochemically active material in contact therewith. At least one of the positive electrode or the negative electrode comprises a carbonized fiber mat current collector impregnated with electrochemically active material. Electrolyte is provided within the container. One or more terminal posts extend from the container or the cover and are electrically coupled to the one or more cell elements.

[0010] A spiral wound cell element for a lead-acid battery is also disclosed. The cell element comprises a positive electrode having a positive current collector and a positive electrochemically active material in contact with the positive current collector and a negative electrode having a negative current collector and a negative electrochemically active material in contact with the negative current collector. At least one of the positive electrode or the negative electrode comprises a carbonized fiber mat current collector impregnated with electrochemically active material. The positive electrode and negative electrode are wound about one another into a spiral.

[0011] These and other features and advantages of devices, systems, and methods according to this invention are described in, or are apparent from, the following detailed descriptions of various examples of embodiments.

BRIEF DESCRIPTION OF DRAWINGS

[0012] Various examples of embodiments of the systems, devices, and methods according to this invention will be described in detail, with reference to the following figures, wherein:

[0013] FIG. 1 is a perspective view of a vehicle for use with a lead-acid battery according to one or more examples of embodiments described herein.

[0014] FIG. 2 is a perspective exploded view of a lead-acid battery according to one or more examples of embodiments described herein, showing a spiral wound cell element. [0015] FIG. 3 is a perspective, partial cutaway view of a lead-acid battery according to one or more examples of embodiments described herein, showing components of a spiral wound cell partially unwound to illustrate relative positioning.

[0016] FIG. 4 is a perspective view showing an example of a spiral wound cell element according to one or more examples of embodiments described herein, showing lugs from positive and negative electrodes positioned on the same end of the spiral wound cell element.

[0017] FIG. 5 is a perspective view showing an alternative example of a spiral wound cell element according to one or more examples of embodiments described herein, showing lugs from positive and negative electrodes positioned, respectively, on opposing ends of the spiral wound cell element. [0018] FIG. 6 is a partial plan view of the cell element shown in FIG. 5, prior to winding, showing a positive electrode and a negative electrode separated by a separator, such as an absorbent glass mat separator.

[0019] FIG. 7 is a plan view representative illustration, showing an example representation of a series connection of spiral wound cell elements, and showing section views of a series of spiral wound cell elements, which may be the cell elements shown in FIG. 4.

[0020] FIG. 8 is a perspective view representative illustration, showing an example representation of a parallel connection of spiral wound cell elements, and showing section views of the parallel connected spiral wound cell elements, which may be the cell elements shown in FIG. 5.

[0021] FIG. 9 is a perspective view showing an example of the cell element shown in FIG. 5, with the spiral wound element covered, enclosed in a cylinder, and a pole or post extending from each opposing end of the cell element.

[0022] FIG. 10 is perspective view showing the parallel connection of spiral wound cell elements shown in FIG. 8, with the cell elements shown in FIG. 9 electrically connected in parallel.

[0023] FIG. 11 is a perspective assembled view of the lead acid battery shown in FIG. 2, with the cover removed and cell elements within the housing and electrically connected by intercell connectors.

[0024] FIG. 12 is a cross-section, side elevation view of a portion of a cell element according to one or more examples of embodiments for use with the lead-acid battery shown and described herein.

[0025] FIG. 13 is an elevation view of an example battery grid or substrate or current collector for use with the lead-acid battery shown and described herein.

[0026] FIG. 14 is an additional elevation view of an example battery grid or substrate or current collector for use with the lead-acid battery shown and described herein.

[0027] FIG. 15 is an elevation view of an alternative example battery grid or substrate or current collector for use with the lead-acid battery shown and described herein, showing section details of the illustrated grid.

[0028] FIG. 16 is a view of a current collector or substrate for use with the lead-acid battery described herein, showing example fibers in exaggerated dimensions for purposes of illustration. [0029] FIG. 17 is another view of the current collector or substrate of FIG. 16 for use with the lead-acid battery.

[0030] FIG. 18 is a sectional view of the current collector or substrate of FIG. 17, taken from section 18 of FIG. 17.

[0031] FIG. 19 is a close up cut away image of an example carbon fiber fabric which may be used with the current collector or substrate of FIGS. 16-18.

[0032] FIG. 20 is a close up cut away image of an alternative example carbon fiber fabric which may be used with the current collector or substrate of FIGS. 16-18.

[0033] FIG. 21 is a close up cut away image of an alternative example carbon fiber fabric which may be used with the current collector or substrate of FIGS. 16-18.

[0034] It should be understood that the drawings are not necessarily to scale. In certain instances, details that are not necessary to the understanding of the invention or render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein.

DETAILED DESCRIPTION

[0035] Referring to the Figures, a battery 100 is disclosed, and in particular a rechargeable battery, such as, for example, a lead-acid battery. According to one or more examples of embodiments, the battery 100 is a lead-acid storage battery. Various embodiments of lead-acid storage batteries may be either sealed (e.g., maintenance-free) or unsealed (e.g., wet).

[0036] In one or more examples of embodiments, the lead-acid storage battery 100 may be a sealed lead-acid battery or AGM lead-acid battery and, to this end, may include an absorbent glass mat 108 (referred to interchangeably herein as “AGM”). The battery may be valve regulated. In one or more further examples of embodiments, the battery is a multi-cell sealed lead-acid battery of the recombinant type having a Monobloc container with cell compartments and a closing/sealed lid, generally porous positive and negative electrodes, porous separator material interleaved between opposite polarity plates, and electrolyte absorbed into the plates and/or separators and present in a starved amount. While specific examples are described and illustrated, the battery 100 may be any secondary battery (e.g., a flooded battery or battery without an AGM) suitable for the purposes provided. [0037] One example of a battery 100 is provided and shown in a vehicle 102 in FIG. 1. While a vehicle battery is shown and described, the disclosure and system described herein are not limited thereto. The battery 100 may be any type of lead-acid battery, including for example, industrial or back-up batteries, as well as other types of lead-acid batteries. In the illustrated embodiment(s) described herein and discussed above, the battery 100 may be an AGM lead-acid battery having positive and negative electrodes or plates 104, 106 which are separated by an absorbent glass mat 108 that absorbs and holds the battery’s acid or electrolyte and prevents it from flowing freely inside the battery 100. In this example, the working electrolyte saturation may be at some value below 100% saturation to allow recombinant reactions of hydrogen and oxygen. As indicated, while an AGM lead-acid battery may be illustrated and/or described herein, it is contemplated that the inventions described herein may be used without an absorbent glass mat, and/or instead may be used with a traditional separator.

[0038] The lead-acid battery 100 includes several cell elements 110 which are provided in one or more separate compartments 112 of a container or housing 114. A cover 116 is provided for the container or housing 114 and may be sealed to the container 114. In various embodiments, the container 114 and/or cover 116 includes battery terminals 118a, 118b. The battery cover 116 may also include one or more filler hole caps and/or vent assemblies.

[0039] More specifically, the battery 100, according to one or more examples of embodiments, is illustrated in FIGS. 2-3, 11. Generally, the battery 100 includes a housing 114, a cover 116, one or more battery elements 110, straps or intercell connectors 136 which electrically connect the battery elements 110 to one another and to battery terminals 118a, 118b. Note the illustrations herein relate to automotive applications, wherein six spiral wound cells are used for producing a standard automotive 12-volt battery. It will be apparent to those skilled in the art after reading this specification that the size and number of cells used to construct the battery may vary widely, depending upon the desired end use. For example, with the spiral wound configuration options described in further detail herein, one or more 2V lead cell(s) can be built into a “fuse- type” modular system. Likewise, while the figures generally illustrate cell containers arranged in a symmetrical fashion, it should be appreciated that the cell containers may be arranged in other patterns (e.g., offset or staggered or other). Further, while each compartment may be illustrated having a generally cylindrical configuration, variations thereon may also be acceptable, such as tapered, hourglass, polygon, etc.). The containers may also have features formed on the bottoms thereof, below the cells.

[0040] According to one or more examples of embodiments disclosed herein, each battery element 110 includes a negative electrode 106, a positive electrode 104, and a separator 108 (or more than one of each electrode and separator such as shown in the cross-section of FIG. 12) in a wound configuration, e.g., spiral wound or jelly roll (see FIGS. 2-6, 11). For example, a spiral wound cell may be formed with one positive electrode and one negative electrode rolled together (including, in some instances a separator or AGM therebetween). Accordingly, the battery 100 disclosed herein includes one or more cell elements 110, each of which may be a wound cell element that includes a positive electrode, a negative electrode, and a separator such as an absorbent glass mat (“AGM”) separator provided between the positive and negative electrodes. Electrolyte or acid (e.g., sulfuric acid electrolyte) may be provided in the cell container.

[0041] As indicated, in some examples of embodiments a plurality of positive electrodes 104 and negative electrodes 106 may be provided in sets or cell elements 110 for producing a battery having a predetermined voltage, for example, in 2-volt intervals (e.g., six 2-volt cells may be used to form a 12-volt battery in a vehicle 102). The number of cell elements 110 or groups or sets may be varied. It will also be obvious to those skilled in the art after reading this specification that the size and number of electrodes 104 and/or 106 in any particular group (including the size and number of the individual current collectors), and the number of groups used to construct the battery 100 may vary depending upon the desired end use.

[0042] The connection of the elements may be a single element, parallel connection (capacity doubled, voltage the same) or series connection (e.g., voltages are additive, i.e., 4V, 6V, etc., with the same capacity). The battery cells or elements 110 may be electrically coupled in series (e.g., FIG. 7) or parallel (e.g., FIGS. 8, 10) by intercell connectors or straps 136. The battery 100 as described herein may be modular. More specifically, as referenced above, modularity may be provided through the use of one or more spiral wound 2-volt battery cells. In this way, the battery cells can be used and combined much like a traditional alkaline battery cell (e.g., a collection of D-cell batteries), to achieve a desired voltage.

[0043] Battery 100, according to one or more examples of embodiments, with the cover removed, is illustrated in FIG. 11. As can be seen, the battery 100 may include several cell elements 110 provided in compartments 112 defined by the container or housing 114, joined together by the intercell connectors or straps 136.

[0044] Each current collector 124, 126, 1001, and therefore each electrode 104, 106, has a lug 134. One or more cast-on straps or intercell connectors 136 are provided which electrically couple the lugs 134 of like polarity in an electrode or plate set or cell element 110 and to connect other respective sets or cell elements 110 in the battery 100.

[0045] In a lead-acid battery as depicted in FIGS. 2-3 and 11 battery terminals 118a, 118b are electrically coupled to the cells at each end of the electrically coupled cell arrangement. Accordingly, one or more positive terminal posts 118a and one or more negative terminal posts 118b (FIGS. 2-4) may be provided, electrically coupled to the cell elements 110. Such terminal posts 118a, 118b typically include portions which may extend through the cover and/or container wall, depending upon the battery design. It will be recognized that a variety of terminal arrangements are possible, including top, side, front or corner configurations known in the art.

[0046] The intercell connectors 136 and/or terminals 118a, 118b may be composed of lead or lead alloy. In one or more examples the lead may be a recycled lead.

[0047] In one example, lugs 134 of the same polarity (positive or negative) for one of said electrodes 104, 106 may be provided at the same end of a battery element 110 (FIG. 4). In this case, intercell connectors 136 or straps, and in some examples a terminal pole 137a, 137b, may be provided on one end of the battery cell cylinder to combine voltage. Alternatively, lugs 134 of different polarity may be provided at opposite ends of the element 110 (see FIGS. 5-6). In this instance, an intercell connector 136 or strap is provided on each end of the cell, and a terminal post or pole 137a, 137b may optionally be provided on the opposing ends of the element 110. In one or more examples of embodiments, a threaded insert may be provided for each pole. With the foregoing arrangements, a valve port may also be provided at one end of the cell.

[0048] As described above, within the container 114 are positive and negative electrodes or plates 104, 106. Referring to FIGS. 3, 4, 5-6, 12-16, the electrodes 104, 106 include electrically conductive positive or negative current collectors or substrates or grids 124, 126 (or current collector 1001 as discussed in further detail herein). Positive paste or electrochemically active material 128 is provided in contact with and/or on the positive grid 124 and negative paste or electrochemically active material 130 is provided on the negative grid 126. To this end, a “grid” or “current collector” may include any type of mechanical or physical support or substrate for the active material. In one or more examples of embodiments, the positive grid or current collector or substrate 124 and/or the negative grid or current collector or substrate 126 may be composed of lead or lead alloy, which in some examples of embodiments may be or include a recycled lead.

[0049] However, as indicated a “grid” as used herein may include any type of mechanical support for the active material. For instance, according to one or more preferred examples of embodiments described herein at least one of the positive grid or the negative grid or current collector may comprise a fibrous material, such as a fiber mat 1005 (see FIGS. 16-21). The fibers may be textile fiber material. For example, in various embodiments, the current collector may be understood to be a felt-like fabric material. According to one or more preferred examples of embodiments, the current collector is a conductive fibrous material forming a conductive fibrous matrix 1005. In another example of embodiments, the current collector or substrate or one such current collector (e.g., either positive or negative) may comprise an oxidized carbon or carbonized fiber mat. In other examples, the fiber mat may be composed of, for instance, oxidized synthetic, organic polymer fibers. More specifically, the conductive fibrous material or conductive fibrous matrix 1005 may be a mat made of oxidized carbon or carbonized fibers which may be textile fiber material. Accordingly, one of skill in the art will appreciate that a carbonized fiber mat 1005 may have an appearance similar to the fiber mats shown in FIGS. 19-21, and the fibers may be woven or non-woven. However, a variety of textile structures are known and it is contemplated that one or more of these structures may be suitable for the purposes provided and may be implemented in place of the illustrated examples.

[0050] In FIGS. 16-17, the carbonized fibers of the mat or matrix 1005 are shown in exaggerated dimensions to illustrate the fibers and/or voids which may be present within the fiber fabric (discussed in further detail hereinbelow). The conductive fibrous matrix provides a void volume formed by voids within the fiber matrix, between the fibers.

These voids may be filled by active material or paste, and/or electrolyte. The voids and fibers also provide enhanced surface area to the current collector for electrochemical activity. In one or more examples of embodiments, the conductive fiber mat 1005 may have undergone a curing step to convert the fiber mat into a stiff current collector or substrate, however in a spiral wound cell this may not be required. The conductive fibrous material may also be present in multiple layers or a single layer.

[0051] The current collector or substrate 1001 may have a strap or frame member 1003 coupled to the mat portion 1005. The strap 1003 is bonded to the top border of the fiber mat 1005. The lead alloy strap may be connected to the fiber mat or substrate by penetration into and/or between the fibers of the fibrous material. The strap 1003 extends along the edge of the current collector 1005, and preferably along the entire length of the edge of the current collector. This strap may be understood to be electrically in communication with the mat portion 1005. Accordingly, the current collector or substrate 1001 comprises a mat of conductive fibers 1005, e.g., carbonized fibers, affixed to a strap 1003 having a lug 134. In this regard, the lead alloy strap 1003 has a lug 134 on a top portion thereof for electrical connection within the battery 100.

[0052] The strap 1003 having a lug 134 may be formed of metal such as lead. In various embodiments, the strap or frame member 1003 may be comprised of a metal or lead alloy. Specifically, in various embodiments, the alloy may be a calcium alloy or calcium tin alloy. In various embodiments, the strap or frame member 1003 may comprise a lead- calcium alloy. In other examples of embodiments, the frame member 1003 may be a lead-calcium-tin alloy. While a lead-calcium alloy and lead-tin-calcium alloy are described, various alloys should be understood as within the scope of this disclosure. In some examples of embodiments, the lead alloy may include one or more of aluminum, tin, silver, antimony, and/or calcium. Likewise, the alloy may also include one or more impurities.

[0053] Referring to FIGS. 11-21, the substrates or grids or current collectors 124, 126, 1001 may be composed the same or similar material. It is contemplated, however, that material composition may also vary between the positive and the negative electrodes 104, 106 or current collectors. To this end, one or both of the current collectors (positive, negative, or both) may be stamped or punched fully framed grids 124, 126 having a frame 137 and a radial arrangement of grid wires 138 forming a pattern of open spaces 139 (various examples of grids 124, 126 suitable for use with the inventions described herein are shown and described in United States Patent Nos. 5,582,936; 5,989,749; 6,203,948; 6,274,274; 6,953,641, 8,709,664, and 9,130,232 which are hereby incorporated by reference herein). In various embodiments, one or both current collectors (positive, negative, or both) may comprise a conductive fiber mat (e.g., current collector 1001). In some embodiments, only the positive electrode 104 may comprise a conductive fiber mat current collector 1001. In other examples of embodiments, only the negative electrode 106 may comprise a conductive fiber mat current collector 1001. Accordingly, in various examples of embodiments, the grid or substrate of the positive electrode 104 or negative electrode 106 may be a punched grid, a continuously cast (concast) grid, an expanded metal grid, a carbon or carbonized felt or fiber substrate, ceramic, and so forth. In some examples of embodiments, the grid or current collector may also include surface roughening or may be subjected to one or more different surface treatments (e.g., solvent, surfactant and/or steam cleaning), such as may be used to improve paste adhesion among other benefits.

[0054] In one example of embodiments, the positive and negative current collectors may also be formed of different thickness. However, it is contemplated that the current collectors may be of the same thickness. For instance, the thickness of each current collector may be varied based upon desired manufacturing and performance parameters.

In one example, thickness may be determined based upon manufacturing requirements, such as for instance, minimum requirements for paste adhesion, improved cycle performance, endurance, or other suitable parameters. In the present case, the thickness of the respective grid(s) is preferably sufficient to withstand the process of winding or coiling without structural damage. In addition to the foregoing, plate thickness within the spiral wound cell or jelly roll can also be varied (via current collector thickness and/or active material thickness and/or separator thickness) to gain higher power performance or higher durability. The space between the plates (plate pitch) might also be varied to improve power or endurance.

[0055] In one or more alternative examples of embodiments, the grid height or current collector height may also or alternatively be varied. For example, the grid or current collector may be provided with a shorter height and the cylinder (wound spiral cell) provided with increased diameter. Such a configuration may be provided to reduce the internal resistance and improve high power performance. Alternatively, a taller grid or current collector (and therefore spiral wound cell) may be used to provide increased capacity to the cell.

[0056] While specific examples are provided for purposes of illustration, variations thereon may be made to provide grid / plate dimensions suitable for the particular application. Likewise, while specific examples of current collector, grid, and substrate arrangements and grid or substrate types are described for purposes of example, one of skill in the art will appreciate that any grid structure or arrangement suitable for the purposes of the battery 100 may be substituted in place of the described grids/current collectors.

[0057] As described in various embodiments herein, the positive and negative electrodes or plates 104, 106 are paste-type electrodes (FIG. 4). Thus, each plate 104, 106 comprises a current collector or grid 124, 126, 1001 pasted with electrochemically active material 128, 130. More specifically, the paste-type electrode includes a current collector or grid which acts as a substrate and an electrochemically active material or paste is provided in contact with and/or on the substrate. The current collectors or grids 124, 126, 1001, including a positive grid and a negative grid, provide an electrical contact between the positive and negative electrochemically active materials or paste 128, 130 which may serve to conduct current. More specifically, positive paste 128 is provided in contact with and/or on the positive grid 124 and negative paste 130 is provided in contact with and/or on the negative grid 126. That is, the positive plate 104 includes a positive grid 124 having or supporting a positive electrochemically active material or paste 128 thereon, and in some examples of embodiments may include a pasting paper or a woven or non- woven sheet material comprised of fibers (e.g., a “scrim”) 132; and the negative plate 106 includes a negative grid 126 having or supporting a negative electrochemically active material or paste 130 thereon, and in some examples of embodiments may include a pasting paper or scrim 132. The scrim, in one or more examples of embodiments may be composed of or include glass fibers. In other examples, the scrim may include other fiber materials, such as but not limited to polymer.

[0058] As described and shown in FIGS. 16-21, the current collector 1001 may comprise a fiber mat portion 1005 which may comprise, for example, a plurality of carbonized fibers. In this example, the current collector may be provided with a paste or impregnated with paste or electrochemically active material, and in some examples of embodiments may be cured, forming an electrode. While the current collector 1001 may be understood to be impregnated with a paste and, at a suitable time during the manufacturing process, may undergo a curing step which in some examples produce a stiff current collector, the use of a spiral wound or jelly roll design also provides stability to the fiber mat current collector and curing may therefore be unnecessary.

[0059] The electrochemically active material or paste (positive and negative) may be formed of compositions including lead or leady oxide. In one or more examples, the lead may be a recycled lead. As is known, the paste or electrochemically active material (positive or negative) is oftentimes a mixture of lead and lead oxide or lead dioxide particles and dilute sulfuric acid, and may include other additives, such as carbon, barium sulfate, and/or expander such as lignosulfonate. It is contemplated that other materials or compositions may be present in the paste mix, such as for example, water, fibers (e.g., polymer or glass), sulfuric acid, and so forth. To this end, similar to a traditional lead- acid battery, a fiber material (e.g., glass, polymer, natural fiber) may be incorporated into the active material of the electrodes. Additives may be provided in varying amounts and combinations to the paste (positive and/or negative) suitable for the intended purposes of the battery. Alternative negative mass / paste recipes may also be provided which accomplish the objectives described herein. For example, the negative active material or paste 130 may also contain fiber and/or “expander” additives, and/or electrochemically active additives, which may help maintain the active material structure and improve performance characteristics, among other things. In some examples, electrochemically active material or fiber may be provided as an additive, such as but not limited to chopped oxidized carbon fiber or oxidized polyacrylonitrile (PAN) fibers.

[0060] Accordingly, the positive electrode or plate 104 may contain a substrate or grid 124 or 1001 with lead dioxide active material or paste 128 thereon or in contact therewith. The negative electrode or plate 106 may be composed of a substrate or grid 126 or 1001 with a spongy lead active material or paste 130 thereon or in contact therewith. The negative paste 130 may, in a preferred embodiment, be substantially similar to the positive paste 128 but may also vary. For example, the negative paste 130 may comprise an oxidized carbon fiber additive 156. Moreover, the negative electrode may comprise a current collector 1001 having negative active mass or material 130 impregnated therein which active mass or material also includes oxidized carbon fibers interspersed therein. [0061] It is contemplated that different materials may be used in connection with the lead-containing paste composition without limiting the objectives described herein, with the present invention not being restricted to any particular materials or mixtures. These materials may be employed alone or in combination as determined by numerous factors, including for example, the intended use of the battery 100 and the other materials employed in the battery.

[0062] As indicated, in some examples of embodiments, positioned between (e.g., interleaved with) the positive and negative electrodes or plates 104, 106 is a separator 108. In a retained electrolyte-type battery 100 such as described in one or more examples herein, the separator 108 may be a porous and absorbent glass mat (AGM). In an AGM lead-acid battery, positive and negative electrodes or plates 104, 106 are separated by an absorbent glass mat 108 that absorbs and holds the battery’s acid or electrolyte and prevents it from flowing freely inside the battery 100. In this system, the working electrolyte saturation is at some value below 100% saturation to allow recombinant reactions of hydrogen and oxygen. In some examples, the absorbent glass mat 108 may also be used with an additional separator (not shown). Various common commercially available separators are known in the art. The separator may be a “U-shape” wrapping the plate or electrode, but the separator or AGM can be a single sheet, or can be a single length concertina with plates separated by 2 layers. As discussed, preferably the element 110 is spiral wound Geliy roll) design, with separator rolled within the layers of the spiral. Accordingly, in various embodiments, the electrode 110 including the current collector, e.g., current collector 1001, may be further wrapped in or interleaved with a separator 108, which in some examples is an AGM separator 108. A single or double layer of separator 108 may be employed. For example, a standard separator may be provided on the positive plate 104 and an AGM 108 may also be employed with the positive/negative plates 104, 106.

[0063] As described, an electrolyte, which is typically sulfuric acid, may be included in the battery 100. In various examples, the electrolyte may include one or more metal ions. To this end, the sulfuric acid electrolyte may be a sulfuric acid solution including one or more metal sulfates.

[0064] A spiral would battery cell may be constructed by spirally winding together under tension the positive electrodes 104 and negative electrodes 106, which are interleaved by the separators 108 into a self-supporting roll dimensioned to form a more or less snug fit within each of the compartments of the container 114. An example of a spiral wound cell is shown in U.S. 3862861, which is hereby incorporated by reference herein in its entirety. The one or more cell elements 110 are then provided in one or more separate compartments 112 of a container or housing 114. The element stack 110 may be compressed during insertion, reducing the thickness of the separator 108. In one or more additional examples of embodiments, the cell element(s) 110 may be further compressed or high compression maintained by placing the cell roll into a tube, such as but not limited to a polymer tube or cylinder 111 (see FIGS. 9-10) that is then inserted into an additional tube, such as but not limited to a metal tube or cylinder. As shown in FIG. 10, the cylinder 111 may be a self-contained battery cell (e.g., a 2 volt cell) having the cell element 110 therein and poles 137a, 138b on each end or on one end. In some embodiments, electrolyte may be provided within the self-contained cell. These self- contained cells may be combined as previously described in series or parallel.

[0065] According to the foregoing description, a lead-acid battery or AGM lead-acid battery is disclosed. The lead-acid battery comprises a container with a cover and one or more compartments. One or more spiral wound cell elements are provided in the one or more compartments. The spiral wound cell elements comprise a positive electrode and a negative electrode. The positive electrode has a positive current collector and a positive electrochemically active material in contact therewith. The negative electrode has a negative current collector and a negative electrochemically active material in contact therewith. At least one of the positive electrode or the negative electrode comprises a carbonized fiber mat current collector impregnated with electrochemically active material. Electrolyte is provided within the container. One or more terminal posts extend from the container or the cover and are electrically coupled to the one or more cell elements.

[0066] A spiral wound cell element for a lead-acid battery is also disclosed. The cell element comprises a positive electrode having a positive current collector and a positive electrochemically active material in contact with the positive current collector and a negative electrode having a negative current collector and a negative electrochemically active material in contact with the negative current collector. At least one of the positive electrode or the negative electrode comprises a carbonized fiber mat current collector impregnated with electrochemically active material. The positive electrode and negative electrode are wound about one another into a spiral.

[0067] Various advantages are obtained by the invention disclosed herein. Among others, the disclosed battery has improved performance. In existing batteries, the service life of a lead-acid battery is foreshortened when the battery is operated below 100% state of charge; which type of duty is typically found in microhybrid vehicles, where idle-stop- start functionality is enabled, or in mild hybrid vehicles with regenerative braking and power assist on launch. In the novel battery disclosed herein, a higher charge acceptance is provided, thereby allowing the battery to operate more efficiently, leading to improved fuel economy.

[0068] In addition, the lead-acid battery has the benefits of spiral wound technology, such as uniform compression, higher compression, high cycleability, and vibration resistance, among other performance benefits. Moreover, the spiral wound cell (and thus battery constructed of same) may also use softer alloy and has lower density of paste than a battery in which plates are stacked in blocks.

[0069] In one or more of the examples of embodiments disclosed herein the spiral wound lead-acid battery has a negative current collector (which is normally a lead alloy grid) that is a carbon fiber substrate comprised of an oxidized polyacrylonitrile fiber or oxidized carbon fiber or carbonized fiber, or the like, in the form of a mat. The fabric current collector described herein advantageously provides enhanced surface area to the current collector for paste and electrolyte, and the corresponding electrochemical reactions of the lead-acid battery. The use of a carbonized fiber grid or oxidized carbon fiber grid also further provides for a lower density of paste. In addition, the fibers can be impregnated with paste. The fiber current collector also weighs less than a traditional lead current collector. A lower weight cell attributable to the carbonized fiber grid also raises the gravimetric energy density, thereby delivering more power with less weight. In the spiral wound lead-acid battery, the carbonized fiber substrate or current collector imparts enhanced charge acceptance, improved durability and service life, as well as low water consumption (improved service life), putting the lead-acid battery close to NiCd/NiMH/Li-ion technology. Furthermore, the spiral wound lead-acid battery having a carbonized fiber negative current collector enables the negative plate to resist undesirable electrochemical effects, such as but not limited to passivation, stratification, gas production, and water loss, leading to extended service life of the battery.

[0070] In addition, the spiral wound battery cells permit modular configurations of a lead-acid battery in EV. In a self-contained 2-volt configuration, a single cell can be produced that can be incorporated in a modular fashion into packs in series or parallel to give alternate voltages, e.g., 2V, 6V, 12V, 48V, 128V, etc. In a more standard configuration, six spiral wound cells may be incorporated into a 12V Monobloc design for automotive applications.

[0071] While specific examples are shown, one of skill in the art will recognize that these are examples only and variations thereon may be made without departing from the overall scope of the present invention.

[0072] As utilized herein, the terms “approximately,” “about,” “substantially”, and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the invention as recited in the appended claims. [0073] It should be noted that references to relative positions (e.g., “top” and “bottom”) in this description are merely used to identify various elements as are oriented in the Figures. It should be recognized that the orientation of particular components may vary greatly depending on the application in which they are used.

[0074] For the purpose of this disclosure, the term “coupled” means the joining of two members directly or indirectly to one another. Such joining may be stationary in nature or moveable in nature. Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another. Such joining may be permanent in nature or may be removable or releasable in nature.

[0075] It is also important to note that the construction and arrangement of the system, methods, and devices as shown in the various examples of embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited. For example, elements shown as integrally formed may be constructed of multiple parts or elements show as multiple parts may be integrally formed, the operation of the interfaces may be reversed or otherwise varied, the length or width of the structures and/or members or connector or other elements of the system may be varied, the nature or number of adjustment positions provided between the elements may be varied (e.g. by variations in the number of engagement slots or size of the engagement slots or type of engagement). The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments.

Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the various examples of embodiments without departing from the spirit or scope of the present inventions.

[0076] While this invention has been described in conjunction with the examples of embodiments outlined above, various alternatives, modifications, variations, improvements and/or substantial equivalents, whether known or that are or may be presently foreseen, may become apparent to those having at least ordinary skill in the art. Accordingly, the examples of embodiments of the invention, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit or scope of the invention. Therefore, the invention is intended to embrace all known or earlier developed alternatives, modifications, variations, improvements and/or substantial equivalents. [0077] The technical effects and technical problems in the specification are exemplary and are not limiting. It should be noted that the embodiments described in the specification may have other technical effects and can solve other technical problems.

Claims

CLAIMS:

1. A lead-acid battery comprising: a container with a cover, the container having one or more compartments; one or more spiral wound cell elements are provided in the one or more compartments, the one or more spiral wound cell elements comprising a positive electrode and a negative electrode, the positive electrode having a positive current collector and a positive electrochemically active material in contact with the positive current collector, the negative electrode having a negative current collector and a negative electrochemically active material in contact with the negative current collector; wherein at least one of the positive electrode or the negative electrode comprises a carbonized fiber mat current collector impregnated with said respective electrochemically active material; electrolyte provided within the container; and one or more terminal posts extending from the container or the cover and electrically coupled to the one or more cell elements.

2. The lead-acid battery of claim 1, wherein the spiral wound cell element comprises a separator between the positive electrode and the negative electrode.

3. The lead-acid battery of claim 2, wherein the separator is an absorbent glass mat.

4. The lead-acid battery of any of claims 1-3, wherein the negative electrode comprises the carbonized fiber mat.

5. The lead-acid battery of any of claims 1-4, wherein the positive electrode has a lug extending from a first end of the spiral wound electrode and the negative electrode has a lug extending from a second end of the spiral wound electrode.

6. The lead-acid battery of any of claims 1-4, wherein the positive electrode has a lug and the negative electrode has a lug, wherein the lug on the positive electrode and the lug on the negative electrode extend from the same end of the spiral wound electrode.

7. The lead-acid battery of claim 1, wherein a plurality of lugs extend from the spiral wound electrode.

8. The lead-acid battery of claim 7, further comprising an intercell connector electrically coupled to the lugs.

9. The lead-acid battery of any of claims 1-8, comprising a plurality of spiral wound cell elements electrically coupled in series.

10. The lead-acid battery of any of claims 1-8, comprising a plurality of spiral wound cell elements electrically coupled in parallel.

11. A spiral wound cell element for a lead-acid battery, the cell element comprising: a positive electrode having a positive current collector and a positive electrochemically active material in contact with the positive current collector; a negative electrode having a negative current collector and a negative electrochemically active material in contact with the negative current collector, wherein at least one of the positive electrode or the negative electrode comprises a carbonized fiber mat current collector impregnated with said respective electrochemically active material; and wherein the positive electrode and negative electrode are wound about one another into a spiral.

12. The lead-acid battery of claim 11, wherein the spiral wound cell element comprises a separator between the positive electrode and the negative electrode.

13. The lead-acid battery of claim 12, wherein the separator is an absorbent glass mat.

14. The lead-acid battery of any of claims 11-13, wherein the negative electrode comprises the carbonized fiber mat.

15. The lead-acid battery of any of claims 11-14, wherein the positive electrode has a lug extending from a first end of the spiral wound electrode and the negative electrode has a lug extending from a second end of the spiral wound electrode.

16. The lead-acid battery of any of claims 11-14, wherein the positive electrode has a lug and the negative electrode has a lug, wherein the lug on the positive electrode and the lug on the negative electrode extend from the same end of the spiral wound electrode.

17. The lead-acid battery of claim 11, wherein a plurality of lugs extend from the spiral wound electrode.

18. The lead-acid battery of any of claims 11-17, wherein the spiral wound cell element is surrounded by a cylinder.

19. The lead-acid battery of claim 18, wherein a positive pole and a negative pole extend from the cylinder.

20. The lead acid-battery of any of claims 18-19, wherein electrolyte is contained within the cylinder.

21. A lead-acid battery having the spiral wound cell element of any of claims 11-20.