Electrochemical cell and manufacturing method thereof

Abstract

To provide a device for use in an electrochemical cell, that can be used both as the outside casing and the current collector of the electrochemical cell, and to provide a manufacturing method thereof.SOLUTION: An electrochemical cell and a manufacturing method of electrochemical cell are described. The device includes a multilayer sheet for storing an electrode material for the electrochemical cell. The multilayer sheet includes an outside layer, an intermediate layer having a conductive substrate, and an inside layer placed on a part of the conductive substrate. The intermediate layer is placed between the outside layer and the inside layer. The inside layer defines an opening for exposing the conductive region of the intermediate layer so that the electrode material can be connected electrically with the conductive region. Consequently, the intermediate layer can act as the current collector of the electrochemical cell.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[1001] This application is a continuation-in-part of and claims priority to U.S. Provisional Patent Application No. 13 / 832,836, entitled "Electrochemical Cells and Methods of Manufacturing the Same," filed March 15, 2013, which claims priority to and the benefit of U.S. Provisional Patent Application No. 61 / 648,967, entitled "Simplified Battery Design," filed May 18, 2012, both of which are incorporated by reference in their entireties herein.

[0002]

[1002] This application also claims priority to and the benefit of U.S. Provisional Patent Application No. 61 / 648,967, entitled "Simplified Battery Design," filed May 18, 2012. [Background technology]

[0003]

[1003] SUMMARY OF THE DISCLOSURE The embodiments described herein relate generally to devices for use in electrochemical cells that can be used as both the outer casing and the current collector of the electrochemical cell, and methods for making such devices.

[0004]

[1004] Some known electrochemical cells (e.g., batteries) can include various shapes and / or sizes, can be based on a wide variety of functionalized materials and internal structures, can be passively or actively controlled, can be rechargeable or non-rechargeable, and / or can have certain commonalities that allow them to convert chemical energy into electrical energy. Some known batteries can include a first electrode with a high electrochemical potential and a second electrode with a lower electrochemical potential compared to the first electrode. Each electrode can include active materials that participate in chemical reactions and / or physicochemical transformations during discharge based on a desired thermodynamic change of matter state, so that a current can flow when the switch is closed. In some cases, two separate conductive networks allow the anode and cathode to be electrically connected to create charge transfer. A separator can be used to separate the anode and cathode, allowing only ions to pass through the separator and also preventing leakage current.

[0005]

[1005] The manufacture of electrical electrodes is a complex, capital-intensive process and typically involves mixing of materials, casting, calendaring, drying, slitting, and processing (folding, rolling, etc.) depending on the battery structure being constructed. Because the electrodes are processed during assembly, and to ensure that the conductive network is in the correct position, all components are compressed into a cohesive assembly, for example, with a binder. However, the binder itself also takes up space, complicates processing, and can impede ionic and electronic conductivity.

[0006]

[1006] Thus, there is a need for improvements in the manufacture of electrochemical cells (e.g., batteries) and battery chemical cells, including, for example, eliminating components of the electrochemical cell and / or reducing the packaging of the electrochemical cell while maintaining the same energy storage capacity. Summary of the Invention

[0007]

[1007] Described herein are electrochemical cells and methods of making electrochemical cells. In some embodiments, the device includes a multi-layer sheet that stores electrode materials for an electrochemical cell. The multi-layer sheet includes an outer layer, a middle layer that includes a conductive substrate, and a conductive substrate disposed over a portion of the conductive substrate. The intermediate layer is disposed between the outer layer and the inner layer, the inner layer defining an opening through which a conductive region of the intermediate layer is exposed such that an electrode material can be electrically connected to the conductive region and the intermediate layer can act as a current collector for the electrochemical cell. [Brief description of the drawings]

[0008] [Figure 1]

[1008] A schematic diagram of a laminate sheet for housing an electrochemical cell according to one embodiment. [Diagram 2]

[1009] FIG. 2 is a cross-sectional view of the laminate sheet of FIG. 1 taken along line 2-2 of FIG. [Diagram 3]

[1010] A cross-sectional view of a portion of an electrochemical cell according to one embodiment. [Figure 4]

[1011] A schematic top view of a portion of a laminate sheet housing an electrochemical cell according to another embodiment. [Diagram 5]

[1012] A schematic top view of a portion of a laminate sheet housing an electrochemical cell according to another embodiment. [Figure 6]

[1013] A schematic top view of a portion of a laminate sheet housing an electrochemical cell according to another embodiment. [Figure 7]

[1014] FIG. 7 is a cross-sectional view of a portion of the laminate sheet of FIG. 6 taken along line 7-7 of FIG. [Figure 8]

[1015] A cross-sectional view of a portion of an electrochemical cell according to another embodiment. [Figure 9]

[1016] FIG. 10 is a cross-sectional view of another portion of the electrochemical cell of FIG. [Figure 10]

[1017] A cross-sectional view of a portion of an electrochemical cell according to another embodiment. [Figure 11]

[1018] A cross-sectional view of a portion of an electrochemical cell according to another embodiment. [Figure 12]

[1019] A perspective view of a portion of an electrochemical cell according to another embodiment. [Figure 13A]

[1020] A perspective view of a portion of an electrochemical cell according to another embodiment. [Figure 13B]

[1021] An angle of a laminate sheet housing an electrochemical cell according to another embodiment is illustrated. [Figure 13C]

[1021] An angle of a laminate sheet housing an electrochemical cell according to another embodiment is illustrated. [Figure 13D]

[1021] An angle of a laminate sheet housing an electrochemical cell according to another embodiment is illustrated. [Figure 13E]

[1022] A portion of a laminate sheet housing an electrochemical cell is illustrated according to another embodiment. [Figure 13F]

[1022] A portion of a laminate sheet housing an electrochemical cell is illustrated according to another embodiment. [Figure 14A]

[1023] A perspective view of a portion of a laminate sheet housing an electrochemical cell according to another embodiment. [Figure 14B]

[1024] FIG. 14B is a cross-sectional view of the laminate sheet of FIG. 14A taken along line 14B-14B of FIG. 14A. [Figure 15A]

[1025] A perspective view of a portion of a laminate sheet housing an electrochemical cell according to another embodiment. [Figure 15B]

[1026] FIG. 15B is a cross-sectional view of the laminate sheet of FIG. 15A taken along line 15B-15B of FIG. 15A. [Figure 15C]

[1026] FIG. 15C is a cross-sectional view of the laminate sheet of FIG. 15A taken along line 15C-15C of FIG. 15A. [Figure 16A]

[1027] Illustrated are process steps for manufacturing an electrochemical cell according to one embodiment. [Figure 16B]

[1027] Illustrated are process steps for manufacturing an electrochemical cell according to one embodiment. [Figure 16C]

[1027] Illustrated are process steps for manufacturing an electrochemical cell according to one embodiment. [Figure 17A]

[1028] A perspective view of an electrochemical cell according to another embodiment. [Figure 17B]

[1029] FIG. 17B is a cross-sectional view of the electrochemical cell of FIG. 17A taken along line 17B-17B of FIG. 17A. [Figure 17C]

[1029] This is an enlarged view of a portion B of FIG. 17B. [Figure 18A]

[1030] An exploded perspective view of an electrochemical cell according to another embodiment, with a portion of the electrochemical cell shown in transparency. [Figure 18B]

[1031] FIG. 18B is an enlarged view of a portion of the electrochemical cell of FIG. 18A. [Figure 18C]

[1032] FIG. 18B is a perspective view of a portion of the electrochemical cell of FIG. 18A in an assembled state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009]

[1033] Described herein are electrochemical cells, such as batteries, and methods of making electrochemical cells, in which the "pouch" or "casing" of an electrochemical cell (also referred to as a "cell") may also serve as the electrochemically functional element (e.g., current collector) of the cell. As described herein, in some embodiments, a cell pouch (e.g., case) may include a laminated sheet formed by an outer layer, an intermediate metal foil layer, and an inner layer. The inner layer may include an opening to define a cavity through which the electrochemically active material of the cell's electrodes may be electrically connected to the metal foil member. Thus, in such embodiments, the metal foil layer of the pouch may serve as the current collector of the cell.

[0010]

[1034] Generally, in the case of secondary batteries, each electrode of an electrochemical cell may contain an active material that may undergo chemical or physicochemical changes during charging and discharging. An electrode may fill or reside within a cavity of an electrochemical cell. A cavity may be defined as the volume of the cell that contains the electrode and, in some cases, may contain additional volume to contain other components of the cell. Thus, in some embodiments, an electrode cavity may contain several different regions.

[0011]

[1035] For example, as discussed above, the cavity can refer to the total volume of the cell that the electrodes are contained in. In some embodiments, the cavity of the cell can include a fluid domain, which is the total collective volume occupied by the fluid suspension within the cavity, which may or may not be continuous or homogenous.

[0012]

[1036] The cavity may also include an active area, which may be a collection of fluidic materials in which the active material is or can be active (i.e. undergoing chemical or physicochemical changes) during charging / discharging, which may vary depending on the operating conditions (e.g. temperature, charging conditions, current, etc.), when in electrical communication with both the current collector and the separator.

[0013]

[1037] The cavity may have zero, one, two, or more ports or openings to facilitate fluid exchange, and the ports may be present on any of the surfaces that define the cavity, including, for example, the sides and / or back. The ports allow for the insertion and withdrawal of specialized equipment that may be used during the manufacture of the cell or may be used, for example, as a feedthrough for equipment during the manufacture of the cell or for equipment that continues to exist after the manufacture is completed. A portion of the area of ​​the cavity may be surrounded by a current collector, and at least some portion of the area of ​​the cavity may be surrounded by a separator. Other portions of the cavity may be surrounded by, for example, a frame seal, a port plug, an electrolyte, a containment device, an intra-cavity mechanical support, an instrument / sensor, and / or a fluid.

[0014]

[1038] The shape of the cavity may be, for example, polygonal (rectangular, hexagonal, etc.), with rounded edges, or other shapes according to the design goals. The depth / thickness of the cavity may be uniform or may vary according to the contour shape. The cavity may include only active areas or may be partitioned into active and inactive areas. The cavity volume may be determined based on, for example, structural, hydrodynamic, Or for other reasons, it may be obstructed by a member that spans the length (eg, thickness) of the volume.

[0015]

[1039] Some embodiments described herein relate to the creation of electrochemical cells and / or methods of manufacturing electrochemical cells in which the electrodes of the cells may include active material, electrolyte, and optional other materials, such as materials participating in the conductive network (e.g., carbon powder or salts), rheology modifiers (e.g., dispersants, fluid stabilizers, and other functional agents), etc. This is differentiated from conventional batteries in that the active material is mobile (e.g., flowable) within the electrolyte (i.e., not fixed in relative position, at least during manufacturing, and optionally not fixed in relative position (i) during a period after assembly when other processing steps are performed, (ii) during conditioning of the assembled battery, (iii) over a portion of the battery's life, (iv) over the entire life cycle of the battery, or (v) over a non-continuous period of the battery's life). The term "during manufacturing" in this context refers to the period from when the electrode material or its material components are first introduced into the cavity region of the battery to when the electrode material or its material components are finally introduced into the cavity region. In some embodiments, the manufacturing method for the cell can include sealing, tabbing, and an overall simplified manufacturing process.

[0016]

[1040] As used herein, the singular forms "a," "an," and "said" include plural referents unless the context clearly dictates otherwise. Thus, for example, the word "port" is intended to mean one port or a combination of ports.

[0017]

[1041] The electrode composition may include, for example, (1) an active material (i.e., a source and sink of ions and electrons), (2) a carbon (or mixture of carbons) or other material whose primary, but not exclusive, function is electronic conduction, and (3) an electrolyte (e.g., a solvent or solvent mixture plus salt) whose primary, but not exclusive, function is ionic conduction. The electrode composition may optionally include other additives that have specific chemical, mechanical, electrical, and / or thermal functions. The electrode formulation may include, for example, the active materials, compositions, and / or semi-solid suspensions described in U.S. Provisional Patent Application No. 61 / 787,382, entitled "Semi-Solid Electrodes Having High Rate Capability," and U.S. Provisional Patent Application No. 61 / 787,372, entitled "Asymmetric Battery Having a Semi-Solid Cathode and High Energy Density Anode," both of which are incorporated herein by reference in their entireties.

[0018]

[1042] Electrodes in conventional electrochemical cells are typically prepared by coating a metal foil substrate with a thin (e.g., about 100 μm to about 200 μm) wet slurry, which is then dried and calendared to the desired thickness. The components of the slurry in this process are typically the active material, conductive additive, binder, and solvent (e.g., commonly N-methylpyrrolidone (NMP)). When the solvent evaporates (in a drying chamber over the transfer line), the binder transforms into a "glue" that holds all the solid particles together in a matrix that bonds to the substrate. It is common for electrodes to be coated with the same material on both sides of the substrate. In this specification, the term "electrode material" refers to the above-mentioned slurry.

[0019]

[1043] There are two general approaches to battery design: (1) wound and (2) stacked. In wound cell designs, electrode sheets are cut to the desired dimensions and then wound into a spiral or jelly-roll shape with a separator inserted between them, then impregnated with electrolyte and packaged appropriately (typically in a cylindrical or rectangular metal can) to allow for containment and electrical connections. In stacked cell designs, electrode sheets are also cut to the desired dimensions and then wound into a spiral or jelly-roll shape with a separator inserted between them, then impregnated with electrolyte and packaged appropriately (typically in a cylindrical or rectangular metal can) to allow for containment and electrical connections. The stacked assemblies can be cut into pieces, but then stacked on top of each other with a separator between them, thereby forming cells consisting of physically separate anode / cathode pairs, rather than contiguous as in the case of wound cells. The stacked assemblies are permeated with electrolyte and generally packaged in pouches / bags, plastic boxes, or metal cans, referred to herein as cell or battery casings, respectively.

[0020]

[1044] In traditional pouch packaging, the pouch can serve several functions. One function is to hermetically isolate the battery materials from the environment. Thus, the pouch serves to prevent harmful substances, such as electrolyte solution and / or corrosive salts, from leaking into the surrounding environment, and can prevent water and / or oxygen from penetrating the cell. Other functions of the pouch include, for example, compression packaging of the inner layers, voltage isolation for safety and operability, and mechanical protection of the battery assembly.

[0021]

[1045] A typical pouch material may include, for example, a laminate (e.g., a multi-layer sheet) formed into two or three solid film-like layers and bonded by adhesive. The term "laminate" as used herein refers to layers of material that are not chemically bonded to each other. For example, the layers are face-to-face contact with each other and bonded using, for example, heat sealing, UV and / or other bonding methods such as adhesives (e.g., anaerobic adhesives). The inner layer may be, for example, a plastic layer, for example, a polyolefin (e.g., non-oriented polypropylene (CPP) or polyethylene). The next or second layer may be, for example, a metal foil layer, for example, aluminum, aluminum alloy, copper, nickel, titanium, stainless steel, gold, platinum or carbon. In some pouch configurations, there may be additional layers. The additional layer may be, for example, a protective coating formed by a plastic such as nylon. Metal foils may provide a hermetic function since they are much less permeable to certain compounds, especially water, than plastics. The inner plastic layer can be heat sealed to itself, which allows for pouch sealing and electrical pass-through. It is determined that in sealing the pouch, when the inner layers (e.g., CPP) of the two pouch laminates are brought into physical contact, heat is applied and the layers melt and fuse together, forming a tight seal if the manufacturing conditions (e.g., power, temperature, duration) are properly selected. For example, if the sealing is performed in a closed loop, an inner volume isolated from the surroundings or outside environment can be created. For electrical pass-through, an electrical tab (e.g., a strip of conductive metal with a ring-like wrapping of a selected plastic such as Surlyn) can be attached (e.g., by ultrasonic welding, fixtures, tape, etc.) to the inner battery assembly with the plastic ring aligned within the pouch to also allow for heat sealing.

[0022]

[1046] The above-mentioned tabulation techniques add manufacturing complexity and cost and may require careful control of quality during manufacturing. For example, polymeric materials are often used around the area where the electrical tabs pass from inside to outside into the pouch to provide a more secure seal and prevent leakage. Failure to properly control this can result in increased costs. The above-mentioned pouch laminates are known to be used as packaging materials in the battery industry, but are not known as electrochemical functional elements of the battery.

[0023]

[1047] Described herein are systems, devices, and methods relating to electrochemical cells having a casing or pouch that includes a multi-layer laminate sheet with at least a first or inner layer formed from a plastic material and a second layer formed from an electrically conductive material such that the multi-layer sheet can be used as an electrochemical functional element of the cell. For example, in some embodiments, the electrically conductive material (e.g., metal foil) of the pouch can be used as a current collector for the cell. In some embodiments, the metal foil can be used as a pass-through tab. Thus, the cell The multi-layer or laminated sheet of the pouch can serve as the packaging material as well as the electrochemical functional material of the cell.

[0024]

[1048] 1-3 illustrate a portion of an electrochemical cell (also referred to herein as an "electrical storage device") according to one embodiment. The electrochemical cell (e.g., battery) may include a casing including two laminate or multi-layer sheets (also referred to herein as "laminate sheets" or "sheets") bonded together to store the cell's electrode materials. As shown in FIGS. 1 and 2, the casing 100 (also referred to herein as a "pouch") may include a laminate sheet 110. The laminate sheet 110 may include a first or inner layer 124 and a second or middle layer 122, and may optionally include a third or outer layer 120. As shown in FIG. 2, the second layer 122 may be bonded to the third layer 120 and the first layer 124 by an adhesive 125. In alternative embodiments, the third layer 120, the second layer 122, and the first layer 124 may be bonded by other methods. For example, the third layer 120, the second layer 122, and the first layer 124 may be placed in a laminated relationship and then the periphery of the layers may be heat sealed, for example. In some embodiments, the first layer 124 and / or the third layer 120 may be molded onto the second layer. In some embodiments, the first layer 124 and / or the third layer 120 may be painted or coated onto the second layer.

[0025]

[1049] The third layer 120 may be formed, for example, from polyamide (e.g., nylon) and may have a thickness of, for example, about 0.025 mm. The second layer 122 may be formed, for example, from an electrically conductive material such as aluminum, an aluminum alloy, or copper and may have a thickness of, for example, about 0.025 mm to 0.040 mm. The first layer 124 may be formed, for example, from a material that is heat-sealable to itself. For example, the first layer 124 may be formed from polypropylene (CPP). The first layer 124 may have a thickness of, for example, 0.040 mm.

[0026]

[1050] 1, the first layer 124 can define one or more openings 126 such that a portion 142 of the second layer 122 is exposed through the opening 126. The exposed portion 142 of the second layer 122 allows an electrochemically active material of an electrode (also referred to as an "electrode material") to contact and electrically connect to the second layer 122, as described in more detail below. The second layer 122 can thus act as a current collector for the cell. The openings 126 can be formed, for example, by laser cutting, stamping, or forming or molding a cavity in the first layer 124.

[0027]

[1051] As shown in FIG. 3, the electrochemical cell casing 100 may include laminate sheets 110 and 110', which are two laminate sheets bonded together, for example, by adhesive, heat sealing, or other suitable bonding methods, to form an airtight seal. The laminate sheet 110' shown in FIG. 3 may be formed the same as or similar to the laminate sheet 110. For example, the laminate sheet 110' may include an inner layer 124', a middle layer 122', and an outer layer 124', each bonded together by an adhesive 125. A first electrode material (not shown) may be disposed on the exposed portion 142 of the second layer 122, and a second electrode material (not shown) may be disposed on the exposed portion 142' of the second layer 122'. For example, one of the cavities 126, 126' may contain an anode electrode and thus be referred to as the anode cavity of the cell, and the other cavity 126, 126' may contain a cathode electrode and thus be referred to as the cathode cavity of the cell.

[0028]

[1052] 3, a separator member 130 can be disposed between laminate sheets 110 and 110'. Separator 130 can be used to separate the anode and cathode portions of the cell, thereby allowing only ions to pass through separator 130 and preventing the cell from shorting out.

[0029]

[1053] In some embodiments, the inner layer 124 of the laminate sheet 110 and the inner layer 124' of the laminate sheet 110' can include a perimeter (not shown in FIG. 3) that extends beyond the perimeter of the separator 130 so that the first layers 124 and 124' can be joined to form a seal. In some embodiments, the inner layers 124 and 124' are each formed from a material that is heat sealable to itself (e.g., CPP, as discussed above), so that when the two laminate sheets 110 and 110' are joined, the first layers 124 and 124' are joined at their respective perimeters and heat sealed to one another to form an airtight seal.

[0030]

[1054] In some embodiments, the cells may include integrated electrical tabs, which may eliminate the need for (i) separate tab elements (e.g., electrode leads), (ii) dedicated tabs for connection to a current collector, and (iii) dedicated tab sealing operations. However, as described herein, in some embodiments, the electrical tabs or leads may be provided as an extension of the second layer (e.g., current collector) of the laminate sheet (e.g., 122 of laminate sheet 110), thereby providing electrical pass-through through the cell seal.

[0031]

[1055] FIG. 4 illustrates a portion of laminate sheet 210 that can be cut along the dashed lines to form three separate laminate sheets, each usable within the casing of an electrochemical cell. As shown in FIG. 4, laminate sheet 210 includes a first or inner layer 224 and a second or middle layer 222, and can optionally include a third or outer protective layer (not shown in FIG. 3). As described above with respect to laminate sheet 110, first layer 224 can be formed from a plastic material, such as, for example, unstretched polypropylene, and can define one or more openings 226 to expose a portion 242 of second layer 222. Second layer 222 can be formed from a conductive material that can be electrically coupled through opening 226 to an electrode material (not shown) disposed on portion 242, such that exposed portion 242 of second layer 222 can be used as a current collector for the cell. First layer 224 can also define an opening 236 to expose additional portion 232 of second layer 222. The exposed portion 232 of the second layer 222 may be coupled to an electrical lead 234 that can serve as a power connection tab and / or be used to supply electrical current to the cell, as shown in Figure 4. For example, the electrical lead 234 may be welded, brazed, crimped, etc. onto the exposed portion 232.

[0032]

[1056] In alternative embodiments, instead of exposed portion 232 being defined by opening 236 in first layer 224, exposed portion 232 may be integral with exposed portion 242 of layer 232. For example, in some such embodiments, exposed portion 232 may extend from exposed portion 242 as a unitary element, and electrode material may be disposed on exposed portion 242 while masking exposed portion 232. In some such embodiments, electrode material may be applied onto exposed portion 242 and exposed portion 232, and then the electrode material on exposed portion 232 may be scraped or otherwise removed, and electrical lead 234 may be bonded onto exposed portion 232.

[0033]

[1057] FIG. 5 illustrates a laminate sheet 310 according to another embodiment. In this embodiment, the laminate sheet 310 includes a first or inner layer 324 and a second or middle layer 322, and may also include a third or outer layer (not shown in FIG. 3). The first layer 324 may be formed of a plastic material, such as, for example, unstretched polypropylene, and may define one or more openings 326 to expose a portion of the second layer 322. As shown in FIG. 5, there are three openings 326 in this embodiment. The second layer 322 may be formed of a conductive material capable of electrically coupling to an electrode material (not shown) disposed on the exposed portion 342 of the second layer 322 through the openings 326. In this embodiment, the second layer 322 is The second layer 222 includes an extension portion 327 that extends beyond the periphery of the inner layer 324. The extension portion 327 can function as a power connection tab for supplying electrical current to the electrode material disposed on the exposed portion 342 of the second layer 222.

[0034]

[1058] 6 and 7 illustrate another embodiment of a laminate sheet that can be used within the casing of an electrochemical cell and can also be used as a current collector for the cell. The laminate sheet 410 includes a first layer 424 and a second layer 422. The first layer 424 can be joined to the second layer 422, for example, by adhesive, heat sealing, or other known bonding methods. The second layer 422 can be formed of a conductive material, for example, aluminum or copper material, and the first layer 424 can be formed of, for example, solid polypropylene (CPP), as described above for the previous embodiment. In this embodiment without a third or outer protective layer, it may be desirable for the second layer 422 to be thicker than the embodiment having a third layer. For example, it may be desirable for the second layer 422 to have a thickness of about 0.075 mm to 0.100 mm.

[0035]

[1059] The first layer 424 defines an opening 426 such that portions 442 of the conductive second layer 422 are exposed through the opening 426, as shown in Figure 6. The exposed portions 442 of the second layer 422 may be electrically connected to an electrochemically active material of an electrode disposed on the second layer 422 within the opening 426. The second layer 422 therefore serves as a current collector for the cell. As described above, the opening 426 may be formed, for example, by laser cutting or stamping.

[0036]

[1060] In some embodiments, the laminate sheets described herein as being used as the casing of an electrochemical cell and the current conductor of the cell may include cavities or openings formed or molded in the laminate sheet. Such cells having a formed laminate sheet may be referred to as a "formed cell". Such laminate sheets may be referred to as a "formed laminate sheet". Such formed laminate sheets may be formed such that at least a portion of the second layer (e.g., metal foil) is formed as a permanent deformation. The deformation may form a cavity in the laminate sheet into which the electrode material of the cell may be disposed. In some embodiments, the upper periphery of the metal foil (e.g., second layer) on which the inner plastic layer is disposed may not be formed. That is, at least an upper ledge may be maintained on which the inner layer may be disposed. In other embodiments, the inner layer may be disposed on at least a portion of the sidewall of the formed cavity region. In some embodiments, the inner layer may be disposed on a portion of the lower surface that defines the cavity region of the formed laminate sheet.

[0037]

[1061] The walls and bottom surface of the formed cavity region of the laminate sheet may have a relatively uniform thickness or may have different thicknesses. The side walls may be formed at various angles relative to the bottom surface defining the cavity. For example, the angle may be formed at an angle between 0 and 90 degrees. In some embodiments, the angle may vary, for example, around the perimeter of the cavity region. In some embodiments, the bottom surface of the cavity region may include raised portions, such as dimpled surfaces, wavy surfaces, protrusions, ridges, etc., that may structurally reinforce the laminate sheet. The cavity region may have a variety of different shapes and sizes. For example, the cavity region may be polygonal (e.g., square, hexagonal, etc.), circular, oval, or other suitable shapes. In some embodiments, the cell casing may include a first laminate sheet that is a formed laminate sheet and a second laminate sheet that is not formed. That is, the opposite side of the cell casing may include an inner layer that defines an opening, for example, die-cut or laser-formed, as described above with respect to the previous embodiment.

[0038]

[1062] FIG. 8 illustrates a first or inner layer, a second or middle layer, and a third or outer layer (respectively FIG. 8 5 illustrates a formed laminate sheet 510 comprising a separator 530 formed from a conductive material (e.g., a metal foil) of the second layer, as described above with respect to the previous embodiment. As described above with respect to the previous embodiment, the second layer may include, for example, a metal foil formed from a conductive material such as aluminum, an aluminum alloy, or copper. The first layer may define one or more openings (not shown) for exposing at least a portion of the second layer. The formed laminate sheet 510 defines a cavity 528 in which an electrode material may be disposed and electrically connected to the exposed conductive material (e.g., a metal foil) of the second layer. In this embodiment, the laminate sheet 510 includes a wall 540 formed at a substantially 90 degree angle relative to a bottom surface 542 of the cavity 528. The bottom surface 542 may be an exposed surface of the second conductive layer. The wall 540 and the bottom surface 542 define the cavity 528. A separator 530 is bonded to the laminate sheet 510 and covers the cavity 528. Laminate sheet 510 may be bonded to laminate sheet 510' on the opposite side of separator 530 to form cell pouch or casing 500, as shown in Figure 9. Laminate sheet 510' may be formed the same or similar to that described for laminate sheet 510 and may define a cavity 528'. Anode electrode material may be disposed in none of the cavities 528, 528' and cathode electrode material may be disposed in the other cavity 528, 528'.

[0039]

[1063] FIG. 10 illustrates a portion of a framed cell casing 600. The cell casing 600 includes a laminate sheet 610 including a first layer 624 and a second layer 622, with a separator 630 bonded to the first layer 624. A cavity 628 is defined by a sidewall 640 of the first layer 624 and a surface 642 of the second layer 622. As with the previous embodiment, the second layer 622 can be formed from a conductive material such as, for example, aluminum, an aluminum alloy, or copper. An electrode material (not shown) can be disposed within the cavity 628 and electrically connected to the exposed conductive material (e.g., a metal foil) of the second layer 622, such that the second layer 622 can serve as a current collector for the cell.

[0040]

[1064] FIG. 11 illustrates a portion of another framed cell casing 700. The cell casing 700 includes a laminate sheet 710 including a first layer 724 and a second layer 722, with a separator 730 bonded to the first layer 724. In this embodiment, a third layer 720 is also included. The third layer may be a plastic protective outer layer of the cell casing. A cavity 728 is defined by a sidewall 740 of the first layer 724 and a surface 742 of the second layer 722. As with the previous embodiment, the second layer 722 may be formed of a conductive material such as, for example, aluminum, an aluminum alloy, or copper. An electrode material (not shown) may be disposed within the cavity 728 and electrically connected to the exposed conductive material (e.g., metal foil) of the second layer 722. The second layer 722 includes a tab portion 727 that extends beyond the outer periphery of the inner layer 724. The tab portion 727 may serve as a power connection tab for supplying current to the electrode.

[0041]

[1065] FIG. 12 illustrates another embodiment of a formed cell casing of an electrochemical cell. The cell casing 900 includes a formed laminate sheet 910 including a first layer 924 and a second layer 922. The laminate sheet 910 can also optionally include a third layer (not shown in FIG. 12). As described above for the previous embodiment, the second layer 922 can be formed of a conductive material such as, for example, aluminum or an aluminum alloy. The first layer 924 defines a first opening 926 to expose at least a portion 942 of the second layer 922. The formed laminate sheet 910 defines a cavity 928 in which an electrode material can be disposed and electrically connected to the exposed portion 942 of the second layer 922. In this embodiment, the laminate sheet 910 includes a wall 940 formed at a substantially 90 degree angle relative to a bottom surface 946 of the first layer 924. The first layer 924 also defines an opening 926 at the perimeter of a wall 940. The wall 940 and a bottom surface 946 together with an exposed portion 942 of the second layer define a cavity 928. The first layer 924 also defines a second opening 936 that exposes a second portion 932 of the second layer 922. The second exposed portion 932 serves as a power connection tab and provides power to the cell. A separator (not shown) can be bonded to the first layer 924 and a second laminate sheet (not shown) can be bonded to the separator and laminate sheet 910 to form the cell casing 900, as described for the previous embodiment.

[0042]

[1066] FIG. 13 illustrates a formed laminate sheet for a cell casing, according to another embodiment. The laminate sheet 1010 includes a first layer 1024 and a second layer 1022. The laminate sheet 1010 can also optionally include a third layer (not shown in FIG. 13A). As described above for the previous embodiment, the second layer 1022 can be formed from a conductive material, such as aluminum or an aluminum alloy. As described for the previous embodiment, a separator (not shown) can be bonded to the first layer 924, and a second laminate sheet (not shown) can be bonded to the separator and the laminate sheet 910 to form the cell casing 900. The first layer 1024 defines a first opening 1026 to expose at least a portion 1042 of the second layer 1022. The formed laminate sheet 1010 defines a cavity 1028 in which electrode material may be disposed and electrically connected to the exposed portion 1042 of the second layer 1022. In this embodiment, the laminate sheet 1010 includes a wall 1040 formed at a substantially 90 degree angle to the exposed surface portion 1042 of the second layer 1022. The wall 1040 and the surface portion 1042 of the second layer define the cavity 1028. In this embodiment, the second layer 1022 includes an extension portion 1027 that extends beyond the outer periphery of the first layer 1024. The extension portion 1027 may serve as a power connection tab to supply electrical current to the cell. As described for the previous embodiment, a separator (not shown) may be bonded to the first layer 1024 and a second laminate sheet (not shown) may be bonded to the separator and the laminate sheet 1010 to form a cell casing.

[0043]

[1067] FIG. 13B is a close-up view of a portion of laminate sheet 1010 illustrating a 90 degree angle formed between wall 1040 and surface 1042. FIGs. 13C and 13D respectively illustrate alternative embodiments of laminate sheets 1010A and 1010B. As shown in FIG. 13C, laminate sheet 1010A can be formed at a 45 degree angle, and as shown in FIG. 13D, laminate sheet 1010B can be formed at a 30 degree angle. FIGs. 13E and 13F each illustrate alternative embodiments of laminate sheets similar to laminate sheet 1010, in which the first layer is disposed on a different portion of the second layer. In FIG. 13E, laminate sheet 1010C shows an embodiment in which the first layer 1024C extends over a portion of surface 1042C of second layer 1022C. In FIG. 13F, laminate sheet 1010D shows an embodiment having a first layer 1024D that does not cover wall portion 1040D of second layer 1022D.

[0044]

[1068] 14A and 14B illustrate a formed laminate sheet for a cell casing according to another embodiment similar to that of FIG. 14A. The laminate sheet 1110 includes a first layer 1124 and a second layer 1122, and can optionally include a third layer (not shown in FIGS. 14A and 14B). As described above for the previous embodiment, the second layer 1122 can be formed of a conductive material such as, for example, aluminum, an aluminum alloy, or copper. The first layer 1124 defines an opening 1126 that exposes at least a portion of a surface 1142 of the second layer 1122. The formed laminate sheet 1110 defines a cavity 1128 in which an electrode material can be disposed and electrically connected to the surface exposed portion 1142 of the second layer 1122. The laminate sheet 1110 includes a wall 1140 formed at a substantially 90 degree angle relative to the surface 1142 of the second layer 1122. The wall 1140 and the surface 1142 of the second layer 1122 define a cavity 1128. In this embodiment, the second layer 1122 also includes raised portions (e.g., protrusions, dimples, etc.) 1148 that structurally reinforce the laminate sheet 1110.

[0045]

[1069] 13A, the second layer 1122 also includes an extension portion 1127 that extends beyond the outer periphery of the first layer 1124. The extension portion 1127 may serve as a power connection tab for supplying electrical current to the cell. As described for the previous embodiment, a separator (not shown) may be bonded to the first layer 1124, and a second laminate sheet (not shown) may be bonded to the separator and laminate sheet 1110 to form a cell casing.

[0046]

[1070] 15A-15C illustrate another embodiment of a formed laminate sheet for a cell casing including structural reinforcement features. The laminate sheet 1210 includes a first layer 1224 and a second layer 1222, and can optionally include a third layer (not shown in FIGS. 16A-16C). As described above for the previous embodiment, the second layer 1222 can be formed of a conductive material such as, for example, aluminum, an aluminum alloy, or copper. The first layer 1224 defines an opening 1226 that exposes at least a portion of a surface 1242 of the second layer 1222. The formed laminate sheet 1210 defines a cavity 1228 in which an electrode material can be disposed and electrically connected to the exposed portion 1242 of the second layer 1122. In this embodiment, laminate sheet 1210 includes a wall 1240 formed at an angle less than 90 degrees relative to a surface 1242 of second layer 1222, where wall 1240 and surface 1242 of second layer 1222 define a cavity 1228. In this embodiment, second layer 1222 also includes a plurality of raised portions (e.g., protrusions, dimples, etc.) 1248 and raised portions 1250 that structurally reinforce laminate sheet 1210.

[0047]

[1071] 16A-16C illustrate various steps in the process of manufacturing an electrochemical cell having a laminate casing that may also function as a current collector for the cell. As shown in FIG. 16A, in step 1, a laminate sheet 310 is placed in a mold to form a cavity in the laminate sheet. As described above, the laminate sheet 1310 may include multiple layers. For example, the laminate sheet 1310 includes a first layer 1324 that defines an opening through which a portion of the second layer 1322 is exposed. As described herein, the laminate sheet 1310 may optionally include a third outer protective layer (not shown). The second layer 1322 may be formed from a conductive material and may be used as a current collector for the electrochemical cell. The second layer 1322 includes a power connection tab 1327, such as tabs 327 and 1027 described above. Step 2 shows the formed laminate sheet defining a cavity 1328 in which an electrode may be placed. In step 3, a masking material is placed over the first layer such that only the exposed portions of the second layer are visible through the masking.

[0048]

[1072] As shown in FIG. 16B, in step 4, an electrode (called "slurry" in FIG. 16B) may be placed on the exposed portion of the second layer. In steps 5 and 6, the electrode may be smoothed or applied along the surface of the exposed portion of the second layer. For example, a blade or linear instrument may be used to apply the electrode. In step 7, the masking is removed, leaving only the portion of the electrode applied on the exposed portion of the second layer. In step 8, as shown in FIG. 16C, a separator may be placed on a portion of the first layer such that the separator covers the electrode. In step 9, the completed laminate sheet and separator of step 8 may be joined with another completed laminate sheet. For example, the electrode of the laminate sheet of step 8 may be a cathode electrode, and the electrode of the other laminate sheet may include an anode electrode. In step 10, a vacuum and heat sealing process may be performed to seal the two laminate sheets together to form a completed cell shown in step 11.

[0049]

[1073] In conventional batteries, the anodes of different layers (e.g., in wound and stacked configurations) are electrically connected in parallel to each other, as are the cathodes, thereby sharing the same medium. It is dictated that two electrodes (anode or cathode) are on either side of a single metal foil layer. Such configurations are commonly described using single letter abbreviations such as ACCAACC...AAC, where A=anode layer and C=cathode layer. The duplicated letters for the intermediate layer indicate a dual coated configuration.

[0050]

[1074] In some embodiments, in the bi-layer laminates described for the previous embodiments (e.g., a plastic layer partially disposed on a metal foil), the cells are referred to as bipolar batteries or cells. FIG. 17A illustrates a bipolar cell 1452 including four electrode cells 1400. In such a bipolar cell, the exposed metal foil layer (e.g., an anode-cathode pair) of one cell 1400 is disposed adjacent to that of an adjacent cell 1400, as shown in FIG. 17B. Electrical contact of the adjacent foil layers is achieved by various methods, such as mechanical compression, use of conductive paste, welding, brazing, soldering, or other suitable techniques. In such a bipolar stack, the stack voltage reflects the series connection of all the cells that compose it, and is therefore substantially equal to the sum of the individual cell voltages.

[0051]

[1075] 18A-18C illustrate another embodiment of a formed cell casing for an electrochemical cell. The cell casing 1500 includes a formed laminate sheet 1510 and a formed laminate sheet 1510'. The laminate sheet 1510 includes a first layer 1524 bonded to a second layer 1522, and the laminate sheet 1510' includes a first layer 1524' bonded to a second layer 1522'. The first layers 1524, 1524' may be bonded to the respective second layers 1522, 1522', for example, by an adhesive (not shown). The first layers 1524, 1524' may be formed of, for example, unstretched polypropylene, and the second layers 1522, 1522' may be formed of, for example, an aluminum or copper material. In this embodiment without a third protective layer, the second layer 1522, 1522' can be formed thicker, for example 0.075-0.100 mm thick, and the first layer can have a thickness of, for example 0.040 mm. The first layer 1524' and second layer 1522' of the second laminate sheet 1510' are shown in perspective in Figures 18A-18C for illustrative purposes. As described above for the previous embodiments, each second layer 1522, 1522' can be formed from a conductive material, such as, for example, aluminum, an aluminum alloy, or copper.

[0052]

[1076] The first layers 1524, 1524' each define an opening 1526, 1526' exposing a cavity and a portion 1542, 1542' of the second layers 1522, 1522', respectively. The second layers 1522, 1522' each include an extended portion 1542, 1542' exposed on either side of the first layers 1524, 1524' and an extended portion 1527, 1527' also exposed on either side of the first layers 1524, 1524'. The formed laminate sheet 1510 defines a cavity 1528, and the second laminate sheet 1510' also defines a cavity (not shown). Cavity 1528 and the cavity of second laminate sheet 1510' combine to form an electrode cavity in which a stacked electrode 1554 may be positioned and electrically connected to exposed portion 1542 of second layer 1522 and exposed portion 1542' of second layer 1522'.

[0053]

[1077] The stacked electrode 1554 may be a conventional electrode comprising multiple electrodes, each including electrode material disposed on a metal foil sheet, and including a pair of electrical connection tabs 1556 and 1558. The electrode stack 1554 may also include a separator (not shown) disposed between the multiple electrodes. The tabs 1556 and 1558 may extend from the metal foil sheet and be welded to the laminate sheets 1510 and 1510'. As shown in FIG. 18C, the tab 1556 may be welded to the exposed portion 1527 of the laminate sheet 1510, and the tab 1558 may be welded to the exposed portion 1527' of the laminate sheet 1510', as shown at weld site 1560. That is, as shown in FIG. 18C, the tab 1556 may be welded to the exposed portion 1527' of the laminate sheet 1510'. The bottom of exposed portion 1527 is welded to its upper surface, and tab 1558 is welded to its top surface. The thicker second layer 1522, 1522', as described above, facilitates welding of tabs 1556 and 1558.

[0054]

[1078] Laminate sheets 1510 and 1510' may be bonded together, for example, by heat sealing with electrode slacks 1554 disposed within the electrode cavities. Second layers 1522 and 1522' may serve as power connections for electrochemical cell 1500 with tabs 1556 and 1558 welded to exposed portions 1527 and 1527', respectively, thus eliminating the need for pass-through electrical tabs.

[0055]

[1079] In some embodiments, the electrode material can be cast into the open cavity of the cell by using conventional coating, drying and calendaring processes. The coating can be continuous or discontinuous to accommodate wound, stacked or other cell geometries. In other embodiments, the inner layer and foil layer, the foil layer and the outer layer (if there are three layers), or both, are not chemically bonded by adhesives, but instead may simply be in physical contact. Adjacent layers of the laminate may be sealed, and contact between them may be established using mechanical means, such as compressive forces imposed by external plates, tie rods or bands. In another embodiment, the laminate may be used only in the end cells of a stacked assembly. In yet another embodiment, the laminate cell design and assembly approach may be used on either the anode or cathode, but not on both sides.

[0056]

[1080] In another embodiment, the laminate may be manufactured using conventional processes. For example, a foil substrate layer may be coated with the electrode material by conventional methods (e.g., coating, drying, calendaring), and may optionally be coated in discrete patches. A framing material may then be applied to the foil substrate to create the laminate. In this example, the electrode is not a slurry-based electrode, but rather the electrode may be a conventional electrode (e.g., a shaped active material and conductive additives in a solid matrix held together by a binder, with an electrolyte incorporated within the pores).

[0057]

[1081] In some embodiments, the laminate current collector of the cell as described herein can be configured to perform a heat exchange function, i.e., it can also function as a heat collector and a heat sink. In some applications, it is desirable to keep the cell operating temperature within a certain range (e.g., −40° C. to 60° C., or 20° C. to 55° C., or 0° C. to 55° C., or 15° C. to 30° C.), and it is desirable to collect and transfer heat generated during cell operation from the active region of the cell to another region of the cell where the heat can be dissipated, anywhere outside the active region. Regions of the foil layer can serve as (1) cooling fins in the surrounding environment, such as air, a controlled (e.g., temperature, humidity, etc.) gaseous environment, a conductive coolant (e.g., water, water / glycol mixture, heat exchange fluid, etc.), (2) a thermally conductive path that is attached to supporting thermal management hardware and systems by appropriate methods (e.g., chemical bonding such as welding, brazing, soldering, or physical contact such as compression contact, pressure welding, cofolding, etc.), or (3) a radiative surface. Heat transfer in the opposite direction is also possible, for example to facilitate start-up or the start-up sequence from low temperature conditions (e.g., -100°C, -60°C, -40°C, -20°C, <0°C or <15°C) where the current collecting portions of the laminate are used to transfer heat to the cell from another heat source.

[0058]

[1082] In some embodiments, the electrochemical cells described herein can be connected in series and packaged with an inert gas. For example, multiple cells can be stacked in series and then placed in a housing (e.g., a can). The interior volume of the housing can then be purged with the inert gas and then hermetically sealed. As described herein, the laminate sheet provides a first seal for the individual cells, and the outer housing can be sealed against the environment (e.g., a moisture-free environment). ) In addition, the inert gas enhances the safety of the cells, batteries, and / or modules by reducing or preventing sparks and fire.

[0059]

[1083] Although various embodiments have been described above, they are presented by way of example only, not limitation, and various changes in form and detail may be made. Although the methods described above show certain events occurring in a particular order, the order of certain events may be modified. Furthermore, some of the events may be performed simultaneously in a parallel process as well as in the order described, where possible. Any portions of the apparatus and / or methods described herein may be combined in any combination, except in mutually exclusive combinations. The embodiments described herein may include various combinations and / or subcombinations of the functions, elements, and / or features of the different embodiments described.

[0060]

[1084] Additionally, certain temperatures, pressures, and other measurements, calculations, and / or values ​​are set forth in approximate terms, but the values ​​used may not be precise and a wide variety of values ​​may be used. For example, although the formed cells in FIG. 8 are shown including 90 degree angles, other angles may be used in some embodiments.

Claims

1. A first insulating layer; a first current collector disposed on a first portion of the first insulating layer; a first electrode material disposed on the first current collector; A second insulating layer; a second current collector disposed on the first portion of the second insulating layer; a second electrode material disposed on the second current collector; a separator disposed between the first insulating layer and the second insulating layer, the separator bonded to a second portion of the first insulating layer and to a second portion of the second insulating layer to isolate the first electrode material from the second electrode material, the separator extending beyond the first electrode material and the second electrode material.

2. 10. The apparatus of claim 1, further comprising a first tab coupled to the first current collector, the first tab extending beyond each of the first and second insulating layers.

3. 3. The apparatus of claim 2, further comprising a second tab coupled to the second current collector, the second tab extending beyond each of the first and second insulating layers.

4. 2. The device of claim 1, wherein the first current collector is coupled to the first insulating layer and the second current collector is coupled to the second insulating layer.

5. The device of claim 1 , wherein the first insulating layer is heat fused to the second insulating layer.

6. The device of claim 1 , wherein the separator is bonded to at least a portion of the first insulating layer to form a seal around the first electrode material.

7. The device of claim 1 , wherein the separator is bonded to at least a portion of the second insulating layer to form a seal around the second electrode material.

8. 2. The apparatus of claim 1, wherein the first insulating layer and the first current collector are layers of a first multi-layer laminate sheet, and the second insulating layer and the second current collector are layers of a second multi-layer laminate sheet.

9. 2. The device of claim 1, wherein the first current collector has a first side and a second side, the first side being disposed on the first insulating layer and the first electrode material being disposed on the second side.

10. 2. The device of claim 1, wherein the second current collector has a first side and a second side, the first side being disposed on the second insulating layer and the second electrode material being disposed on the second side.

11. a first pouch half having a first conductive region and a first sealing region; a first electrode material disposed on the first conductive region; a second pouch half having a second conductive region and a second sealing region; a second electrode material disposed on the second conductive region; a separator disposed between the first pouch half and the second pouch half, the separator extending beyond the first electrode material and the second electrode material, the first pouch half bonded to the second pouch half to form an electrochemical cell, the separator bonded to the first sealing area and the second sealing area to isolate the first electrode material from the second electrode material.

12. 12. The apparatus of claim 11, further comprising a first tab coupled to the first current collector, the first tab extending beyond each of the first and second insulating layers.

13. 12. The apparatus of claim 11, further comprising a second tab coupled to the second current collector, the second tab extending beyond each of the first and second insulating layers.

14. 12. The apparatus of claim 11, wherein at least one of the first conductive region and the second conductive region includes an angled wall portion that at least partially defines the conductive region.

15. 12. The device of claim 11, wherein the first pouch half is heat sealable to the second pouch half.

16. 12. The device of claim 11, wherein the first pouch half includes an insulating layer, and the first conductive area is disposed on the insulating layer.

17. 12. The apparatus of claim 11, wherein the first pouch half comprises a multi-layer laminate sheet.

18. 12. The device of claim 11, wherein the second pouch half includes an insulating layer, and the second conductive area is disposed on the insulating layer.

19. 12. The apparatus of claim 11, wherein the second pouch half comprises a multi-layer laminate sheet.

20. 12. The device of claim 11, wherein the first conductive region has a first surface and a second surface, the first surface being bonded to the first sealing region and the second surface being bonded to the first electrode material.

21. 12. The device of claim 11, wherein the second conductive region has a first surface and a second surface, the first surface being bonded to the second sealing region and the second surface being bonded to the second electrode material.

22. a casing for an electrochemical cell comprising a first portion and a second portion, the first portion comprising a first conductive region and a first sealing region, the second portion comprising a second conductive region and a second sealing region, the first sealing region and the second sealing region being formed of a material heat sealable thereto, the first portion of the casing configured to define a first volume for receiving a first electrode material on the first conductive region, and the second portion of the casing configured to define a second volume for receiving a second electrode material on the second conductive region; a separator disposed between the first volume and the second volume, the separator extending beyond the first electrode material and the second electrode material such that edges of the separator are bonded to at least a portion of the first sealing region and the second sealing region.

23. 23. The apparatus of claim 22, further comprising a first tab coupled to the first current collector, the first tab extending beyond each of the first and second insulating layers.

24. 23. The apparatus of claim 22, further comprising a second tab coupled to the second current collector, the second tab extending beyond each of the first and second insulating layers.

25. 23. The apparatus of claim 22, wherein the separator is coupled to at least a portion of the first sealing region to form a seal around the first volume.

26. 23. The apparatus of claim 22, wherein the separator is coupled to at least a portion of the second sealing region to form a seal around the second volume.

27. 23. The apparatus of claim 22, wherein at least one of the first and second portions of the casing is a multi-layer laminate sheet.

28. 23. The device of claim 22, wherein the first conductive region has a first surface and a second surface, the first surface being bonded to the first sealing region and the second surface being bonded to the first electrode material.

29. 23. The device of claim 22, wherein the second conductive region has a first surface and a second surface, the first surface being bonded to the second sealing region and the second surface being bonded to the second electrode material.

Images