Electrode body and energy storage device

Abstract

This invention relates to an electrode body and an energy storage device that allows for easy disassembly of the electrode body to separate a pair of electrode plates. The electrode body disclosed herein is a wound body formed by winding a positive electrode plate (10) and a negative electrode plate (20) with a first separator (30A) and a second separator (30B) in between. The first separator (30A) is bonded to the positive electrode plate (10) but not to the negative electrode plate (20). On the other hand, the second separator (30B) is bonded to the negative electrode plate (20) but not to the positive electrode plate (10). Furthermore, both the second terminal portion (30Be) of the second separator (30B) and the first terminal portion (30Ae) of the first separator (30A) are exposed on the outer surface of the wound body. Additionally, the separator winding portion (40s) with only the first separator (30A) and the second separator (30B) wound has a non-bonded region (30X) where the separators are not bonded to each other. Furthermore, a first adhesive tape (80) is attached to the outermost surface of the winding body, and a first peeling portion (82) is formed at one end of the first adhesive tape (80).

Description

Technical Field

[0001] The technology disclosed herein relates to an electrode body and an energy storage device. Background Technology

[0002] Energy storage devices such as lithium-ion secondary batteries include, for example, an electrode body having a pair of electrode plates (positive and negative plates) and a battery casing housing the electrode body. As an example of the electrode body of such an energy storage device, a wound electrode body is provided, in which the positive and negative plates are wound together with two separators in between. Such wound electrode bodies are disclosed in Patent Documents 1 and 2.

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Application Publication No. 2015-210980

[0006] Patent Document 2: Japanese Application Publication No. 2013-243070 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] Furthermore, with increasing awareness of environmental issues in recent years, recycling technologies for recovering valuable metals from used energy storage devices and reusing them have attracted attention. In this recycling technology, firstly, the electrode body is removed from the used energy storage device. Next, the electrode body is immersed in an acid solution to obtain a metal solution. Then, various separation processes (neutralization precipitation, solvent extraction, etc.) are performed on the metal solution. Thus, the desired valuable metal can be recovered from the electrode body.

[0009] However, in the aforementioned regeneration technology, both the metal components from the positive electrode and the metal components from the negative electrode are contained in the molten metal. In this case, the types and number of separation processes required to recover valuable metals from the molten metal increase. As a result, there is a potential decrease in the recovery rate of valuable metals and an increase in regeneration costs. Therefore, in the field of regeneration technology for energy storage devices, there is a need for a technique that can appropriately disassemble the electrode body to separate a pair of electrode plates.

[0010] Solution for solving the problem

[0011] The electrode body disclosed herein comprises a strip-shaped first electrode plate, a strip-shaped first diaphragm, a strip-shaped second electrode plate, and a strip-shaped second diaphragm. Furthermore, the electrode body is a wound body formed by winding the first electrode plate and the second electrode plate with the first and second diaphragms separated by the first and second diaphragms. The first diaphragm is bonded to the first electrode plate but not to the second electrode plate, and the second diaphragm is bonded to the second electrode plate but not to the first electrode plate. Additionally, the electrode body has a diaphragm winding portion formed on the outer periphery of the wound body, where only the first and second diaphragms are wound, and the first diaphragm is wound around the outermost periphery of the diaphragm winding portion. A second terminal portion, serving as the winding end of the second diaphragm, extends from the first terminal portion, serving as the winding end of the first diaphragm, and protrudes to the outer surface of the wound body. At least one of the first opposing portion between the inner surface of the first diaphragm and the outer surface of the second diaphragm, and the second opposing portion between the outer surface of the first diaphragm and the inner surface of the second diaphragm, in the aforementioned diaphragm winding portion has a non-bonded area where the first and second diaphragms are not bonded. Furthermore, the non-adhesive region extends inward from the first terminal portion and / or the second terminal portion toward the winding direction. In addition, in the electrode body disclosed herein, a first adhesive tape is adhered to the outermost surface of the wound body, spanning both the first terminal portion and the second terminal portion, and at least one of the two ends of the first adhesive tape in the circumferential direction forms a first peel portion that is not attached to the outermost surface of the wound body.

[0012] In the disclosed electrode body, a first diaphragm is bonded to a first electrode plate, and a second diaphragm is bonded to a second electrode plate. Furthermore, the first diaphragm and the second electrode plate are not bonded to each other, nor is the second diaphragm bonded to the first electrode plate. This electrode body can be easily separated into a first electrode plate bonded to the first diaphragm and a second electrode plate bonded to the second diaphragm by unwinding the two diaphragms.

[0013] Furthermore, the electrode body disclosed herein also has a structure that allows for easy unwinding of the two diaphragms. Specifically, a diaphragm winding section is formed on the outer periphery of a conventional wound electrode body, where only two diaphragms are wound without passing through the electrode plate. If the diaphragms adhere to each other throughout the entire area of ​​this diaphragm winding section, unwinding the diaphragms becomes very difficult. Therefore, in the electrode body disclosed herein, the second end of the second diaphragm extends from the first end of the first diaphragm wound around the outermost periphery of the diaphragm winding section. Moreover, the diaphragm winding section has a non-adhesive region extending inward from the first end and / or the second end toward the winding direction. Thus, the diaphragm winding can be easily unwound by grasping the first end and / or the second end and pulling.

[0014] Furthermore, in the electrode body disclosed herein, a first peeling portion that does not adhere to the outermost surface of the wound body is formed at at least one end of the first adhesive tape that fixes the first terminal portion and the second terminal portion. This prevents damage to the first terminal portion or the second terminal portion when peeling off the first adhesive tape. As a result, when unwinding the diaphragm, the first terminal portion and / or the second terminal portion can be properly gripped.

[0015] As described above, according to the electrode body disclosed herein, the diaphragm winding at the outer periphery (diaphragm winding portion) of the electrode body can be easily unwound. Furthermore, when the diaphragm winding is unwound, the electrode body can be easily separated into a first electrode plate bonded to the first diaphragm and a second electrode plate bonded to the second diaphragm. As a result, a pair of electrode plates can be provided to the regeneration process one by one, thus contributing to the efficiency of valuable metal recovery and the reduction of regeneration costs. Attached Figure Description

[0016] Figure 1 It is a schematic three-dimensional diagram representing an energy storage device.

[0017] Figure 2 It is along Figure 1 A schematic longitudinal section view of line II-II in the diagram.

[0018] Figure 3 It is along Figure 1 A schematic longitudinal section view of line III-III in the diagram.

[0019] Figure 4 It is along Figure 1 A schematic cross-sectional view of line IV-IV in the diagram.

[0020] Figure 5 It is a schematic three-dimensional view of the electrode body installed on the sealing plate.

[0021] Figure 6 It is a schematic three-dimensional diagram showing an electrode body with a positive second current collector and a negative second current collector installed.

[0022] Figure 7 This is a schematic diagram showing the structure of the electrode body in the first embodiment.

[0023] Figure 8 This is a schematic front view of the electrode body according to the first embodiment.

[0024] Figure 9 It is along Figure 8 A schematic longitudinal section view of the IX-IX line.

[0025] Figure 10 It will Figure 9An enlarged cross-sectional view of the area near the adhesive tape of the electrode body shown.

[0026] Figure 11 It will Figure 9 The diagram shows a cross-sectional view of the electrode body after disassembly.

[0027] Figure 12 This is an enlarged cross-sectional view of the area near the adhesive tape of the electrode body in other embodiments.

[0028] Figure 13 It will Figure 12 The diagram shows a cross-sectional view of the electrode body after disassembly.

[0029] Figure 14 This is a schematic front view of an electrode body in another embodiment.

[0030] Figure 15 This is a schematic front view of an electrode body in another embodiment.

[0031] Figure 16 This is a schematic front view of an electrode body in another embodiment.

[0032] Figure 17 This is a schematic front view of an electrode body in another embodiment. Detailed Implementation

[0033] Hereinafter, embodiments of the technology disclosed herein will be described with reference to the accompanying drawings. Furthermore, matters necessary for implementing the technology disclosed herein, other than those specifically mentioned in this specification (e.g., the general structure and manufacturing process of a battery), can be understood by those skilled in the art based on prior art in the field. The technology disclosed herein can be implemented based on the content disclosed in this specification and common technical knowledge in the field. Furthermore, the expression "A to B" indicating scope in this specification includes the meaning of "A or more and B or less," and also includes the meanings of "preferably greater than A" and "preferably less than B."

[0034] Furthermore, the term "energy storage device" in this specification encompasses the concept of a device in which a charge-discharge reaction occurs by the movement of a charge carrier between a pair of electrodes (positive and negative electrodes) via an electrolyte. That is, the energy storage devices disclosed herein include secondary batteries such as lithium-ion batteries, nickel-metal hydride batteries, and nickel-cadmium batteries, as well as capacitors such as lithium-ion capacitors and double-layer capacitors.

[0035] In addition, in the figures referenced in this specification, reference numeral X indicates "depth direction," reference numeral Y indicates "width direction," and reference numeral Z indicates "height direction." Furthermore, in the depth direction X, F indicates "front," and Rr indicates "rear." In the width direction Y, L indicates "left," and R indicates "right." And in the height direction Z, U indicates "up," and D indicates "down." However, these directions are provided for ease of explanation and are not intended to limit the installation method when using the energy storage device disclosed herein.

[0036] <First Implementation>

[0037] 1. Structure of energy storage equipment

[0038] The following section describes the structure of the energy storage device and the electrode body used in it. Figure 1 It is a schematic three-dimensional diagram representing an energy storage device. Figure 2 It is along Figure 1 A schematic longitudinal section view of line II-II in the diagram. Figure 3 It is along Figure 1 A schematic longitudinal section view of line III-III in the diagram. Figure 4 It is along Figure 1 A schematic cross-sectional view of line IV-IV in the diagram. Figure 5 It is a schematic three-dimensional view of the electrode body installed on the sealing plate. Figure 6 It is a schematic three-dimensional diagram showing an electrode body with a positive second current collector and a negative second current collector installed. Figure 7 This is a schematic diagram showing the structure of the electrode body in the first embodiment. Figure 8 This is a schematic front view of the electrode body according to the first embodiment. Figure 9 It is along Figure 8 A schematic longitudinal section view of the IX-IX line. Figure 10 It will Figure 9 An enlarged cross-sectional view of the area near the adhesive tape of the electrode body shown. Figure 11 It will Figure 9 The diagram shows a cross-sectional view of the electrode body after disassembly.

[0039] like Figure 2 As shown, the energy storage device 100 includes an electrode body 40 and a battery casing 50 for housing the electrode body 40. The specific structure of the energy storage device 100 will be described below.

[0040] (1) Battery casing

[0041] The battery casing 50 is a frame that houses the electrode body 40. Although not shown in the figure, a non-aqueous electrolyte is also housed inside the battery casing 50. Figure 1The battery casing 50 shown has a flat, bottomed rectangular (square) shape. Furthermore, conventionally known materials can be used for the battery casing 50 without particular limitation. For example, the battery casing 50 is preferably made of metal. Examples of materials for this battery casing 50 include aluminum, aluminum alloys, iron, and iron alloys.

[0042] like Figure 1 and Figure 2 As shown, the battery casing 50 includes an outer body 52 and a sealing plate 54. The outer body 52 is a flat, bottomed, rectangular container with an opening 52h on its upper surface. The outer body 52 has a bottom wall 52a that is generally rectangular in plan view, a pair of long side walls 52b extending upward U in the height direction Z from the long side of the bottom wall 52a, and a pair of short side walls 52c extending upward U in the height direction Z from the short side of the bottom wall 52a. On the other hand, the sealing plate 54 is a plate-shaped member that is generally rectangular in plan view and blocks the opening 52h of the outer body 52. ​​Moreover, the outer periphery of the sealing plate 54 is joined (e.g., welded) to the outer periphery of the opening 52h of the outer body 52. ​​Thus, a battery casing 50 that is internally airtight is produced. In addition, an injection hole 55 and a gas venting valve 57 are provided in the sealing plate 54. The injection hole 55 is a through hole provided for injecting electrolyte into the interior of the sealed battery casing 50. Furthermore, the electrolyte injection hole 55 is sealed by the sealing member 56 after the electrolyte is injected. In addition, the gas venting valve 57 is a thin-walled part designed to break (open) and vent the gas when a large amount of gas is generated inside the battery casing 50.

[0043] (2) Electrolyte

[0044] As described above, the battery casing 50 contains an electrolyte (not shown) in addition to the electrode body 40. Most of the electrolyte permeates the interior of the electrode body 40. The electrolyte can be any electrolyte used in conventionally known energy storage devices without particular limitation. For example, a non-aqueous electrolyte in which the supporting salt is dissolved in a non-aqueous solvent can be used. Examples of such non-aqueous solvents include carbonate solvents such as ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate. Examples of such supporting salts include fluorinated lithium salts such as LiPF6.

[0045] (3) Electrode terminals

[0046] Additionally, on one side of the width direction Y of the sealing plate 54 ( Figure 1 , Figure 2 A positive terminal 60 is mounted on the left end of the battery casing 50. This positive terminal 60 is connected to a plate-shaped external positive electrode conductive member 62 on the outside of the battery casing 50. On the other hand, on the other side of the sealing plate 54 in the width direction Y... Figure 1 , Figure 2A negative terminal 65 is installed at the right end of the device. A plate-shaped external conductive member 67 is installed on the negative terminal 65. These external conductive members (positive external conductive member 62 and negative external conductive member 67) are connected to other energy storage devices or external equipment via external connection members (busbars, etc.). Furthermore, the external conductive members are preferably made of a metal with excellent conductivity (aluminum, aluminum alloy, copper, copper alloy, etc.).

[0047] (4) Electrode current collector

[0048] like Figures 3 to 5 As shown, in this energy storage device 100, a plurality of (3) electrode bodies 40 are housed within the battery casing 50. While the detailed structure will be described later, each electrode body 40 is provided with a positive electrode tab group 42 and a negative electrode tab group 44 (see reference). Figure 7 and Figure 8 ).like Figure 4 As shown, these electrode tab groups (positive electrode tab group 42 and negative electrode tab group 44) are bent while connected to electrode current collectors (positive current collector 70 and negative current collector 75).

[0049] Specifically, each positive electrode tab group 42 of the plurality of electrode bodies 40 is connected to the positive terminal 60 via a positive current collector 70. This positive current collector 70 is housed inside the battery casing 50. Figure 2 and Figure 5 As shown, the positive current collector 70 includes a first positive current collector 71 and a plurality of second positive current collectors 72. The first positive current collector 71 is a plate-shaped conductive member extending along the inner side of the sealing plate 54 in the width direction Y, and the second positive current collectors 72 are plate-shaped conductive members extending along the height direction Z. Furthermore, the lower end 60c of the positive terminal 60 is inserted into the interior of the battery casing 50 through the terminal insertion hole 58 of the sealing plate 54 and connected to the first positive current collector 71 (see reference). Figure 2 On the other hand, such as Figures 4-6 As shown, the energy storage device 100 is provided with a number of positive second current collectors 72 corresponding to the plurality of electrode bodies 40. Each positive second current collector 72 is connected to the positive electrode tab group 42 of the electrode body 40. Moreover, as... Figure 4 and Figure 5 As shown, the positive electrode tab assembly 42 of the electrode body 40 is bent so that the positive second current collector 72 faces one side 40a of the electrode body 40. As a result, the upper end of the positive second current collector 72 is electrically connected to the positive first current collector 71.

[0050] On the other hand, each negative electrode tab group 44 of the plurality of electrode bodies 40 is connected to the negative terminal 65 via a negative electrode current collector 75. The connection structure on the negative electrode side is substantially the same as the connection structure on the positive electrode side described above. Specifically, the negative electrode current collector 75 includes a first negative electrode current collector 76 and a plurality of second negative electrode current collectors 77. The first negative electrode current collector 76 is a plate-shaped conductive member extending along the inner surface of the sealing plate 54 in the width direction Y, and the second negative electrode current collector 77 is a plate-shaped conductive member extending along the height direction Z (see reference). Figure 2 and Figure 5 Furthermore, the lower end 65c of the negative terminal 65 is inserted into the interior of the battery casing 50 through the terminal insertion hole 59 and connected to the negative first current collector 76 (see reference). Figure 2 On the other hand, multiple negative electrode second current collectors 77 are respectively connected to the negative electrode tab group 44 of the electrode body 40 (see reference). Figures 4-6 Furthermore, the negative electrode tab assembly 44 is bent so that the second negative current collector 77 faces the other side 40b of the electrode body 40. Thus, the upper end of the second negative current collector 77 is electrically connected to the first negative current collector 76. Additionally, metals with excellent conductivity (aluminum, aluminum alloys, copper, copper alloys, etc.) can preferably be used as the electrode current collectors (positive current collector 70 and negative current collector 75).

[0051] (5) Insulating components

[0052] Furthermore, in this energy storage device 100, various insulating components are installed to prevent conductivity between the electrode body 40 and the battery casing 50. Specifically, an external insulating component 92 (see reference) is sandwiched between the positive electrode external conductive component 62 (negative electrode external conductive component 67) and the outer side of the sealing plate 54. Figure 1 This prevents the positive electrode external conductive member 62 and the negative electrode external conductive member 67 from conducting with the sealing plate 54. Additionally, gaskets 90 are installed in the terminal insertion holes 58 and 59 of the sealing plate 54 (see reference). Figure 2 This prevents the positive terminal 60 (or negative terminal 65) inserted into the terminal insertion holes 58 and 59 from conducting with the sealing plate 54. Furthermore, an internal insulating member 94 is disposed between the positive first current collector 71 (or negative first current collector 76) and the inner surface of the sealing plate 54. This internal insulating member 94 has a plate-shaped base 94a between the positive first current collector 71 (or negative first current collector 76) and the inner surface of the sealing plate 54. This prevents the positive first current collector 71 and the negative first current collector 76 from conducting with the sealing plate 54. Moreover, the internal insulating member 94 has a protrusion 94b protruding from the inner surface of the sealing plate 54 toward the electrode body 40 (see reference). Figure 2 and Figure 3This restricts the movement of the electrode body 40 in the height direction Z, preventing direct contact between the electrode body 40 and the sealing plate 54. Furthermore, the multiple electrode bodies 40 are housed in an electrode body support 98 (see reference 54) made of an insulating resin sheet. Figure 3 The electrode body 40 is housed inside the battery casing 50 while covered. This prevents direct contact between the electrode body 40 and the outer casing 52. Furthermore, the materials of the aforementioned insulating components are not particularly limited as long as they have the specified insulation properties. As an example, synthetic resin materials such as polyolefin resins (e.g., polypropylene (PP), polyethylene (PE)) and fluorinated resins (e.g., perfluoroalkoxyalkane (PFA), polytetrafluoroethylene (PTFE)) can be used.

[0053] (6) Electrode body

[0054] The electrode body 40 of this embodiment will now be described. Figure 7 As shown, the electrode body 40 of this embodiment includes a strip-shaped first diaphragm 30A, a strip-shaped first electrode plate (positive electrode plate 10), a strip-shaped second diaphragm 30B, and a strip-shaped second electrode plate (negative electrode plate 20). Hereinafter, the four strip-shaped members constituting the electrode body 40 will also be referred to as "sheet members". Furthermore, the electrode body 40 of this embodiment is a wound body (wound electrode body) formed by winding the positive electrode plate 10 and the negative electrode plate 20 with the first diaphragm 30A and the second diaphragm 30B in between. Moreover, as... Figures 7-9 As shown, the electrode body 40 in this embodiment is flattened into a flat shape as a whole.

[0055] In addition, such as Figure 9 As shown, the flat electrode body 40 has a pair of curved portions 40r with a curved outer surface and a flat portion 40f connecting the pair of curved portions 40r with a flat outer surface. Furthermore, in this energy storage device 100, the electrode body 40 is housed within the battery casing 50 such that the winding axis WL of the electrode body 40 is substantially aligned with the width direction Y of the energy storage device 100 (see reference). Figure 2 That is, the "winding axis direction" in the following description is approximately the same as the width direction Y in the figure. Furthermore, the "winding direction" in the following description refers to the direction from the end portion of the sheet member toward the beginning portion as it is wound along the strip-shaped sheet member (first diaphragm 30A, positive electrode plate 10, second diaphragm 30B, negative electrode plate 20). Additionally, as... Figure 3 As shown, in this embodiment, three electrode bodies 40 are housed inside the battery casing 50. However, the number of electrode bodies housed in one battery casing is not particularly limited; it can be two or more, or it can be one.

[0056] (a) Positive electrode plate

[0057] like Figure 7As shown, the positive electrode plate 10 (first electrode plate) is a long strip-shaped component. The positive electrode plate 10 includes a positive electrode core 12 as a strip-shaped metal foil and a positive electrode active material layer 14 applied to at least one side of the surface of the positive electrode core 12. Furthermore, from the viewpoint of battery performance, the positive electrode active material layer 14 is preferably applied to both sides of the positive electrode core 12. Additionally, in this positive electrode plate 10, the positive electrode tab 12t extends outward from one end edge in the winding axis direction (width direction Y). Figure 7 (The left side of the image is protruding). Furthermore, multiple positive electrode tabs 12t are formed at predetermined intervals along the length L of the elongated strip-shaped positive electrode plate 10. These positive electrode tabs 12t are the areas where the positive electrode core 12 is exposed without the positive electrode active material layer 14 applied. Additionally, a protective layer 16 extending along the length direction of the positive electrode plate 10 is formed in the region adjacent to the end edge of the positive electrode tab 12t side of the positive electrode plate 10.

[0058] As components constituting the positive electrode plate 10, conventionally known materials that can be used in general energy storage devices (e.g., lithium-ion secondary batteries) can be used without particular limitation. For example, as the positive electrode core 12, a metallic material with a specified conductivity can be preferably used. This positive electrode core 12 is preferably made of, for example, aluminum or an aluminum alloy. On the other hand, the positive electrode active material layer 14 is a layer containing positive electrode active material. Hereinafter, the material of the positive electrode active material layer 14 will be described using a lithium-ion secondary battery as an example. However, the following description is not intended to limit the positive electrode plate of the electrode body disclosed herein.

[0059] The positive electrode active material for lithium-ion secondary batteries is a particulate material capable of reversibly absorbing and releasing lithium ions (charge carriers). From the viewpoint of stably manufacturing a high-performance positive electrode plate 10, the positive electrode active material is preferably a lithium transition metal composite oxide. Among the aforementioned lithium transition metal composite oxides, lithium transition metal composite oxides containing at least one of the group consisting of nickel (Ni), cobalt (Co), and manganese (Mn) as the transition metal are particularly preferred. Specific examples include lithium nickel cobalt manganese composite oxide (NCM), lithium nickel composite oxide, lithium cobalt composite oxide, lithium manganese composite oxide, lithium nickel manganese composite oxide, lithium nickel cobalt aluminum composite oxide (NCA), and lithium iron nickel manganese composite oxide. Furthermore, as a preferred example of a lithium transition metal composite oxide that does not contain Ni, Co, and Mn, lithium iron phosphate composite oxide (LFP) is also mentioned. In addition, the term "lithium nickel cobalt manganese composite oxide" in this specification refers to oxides that contain additive elements in addition to the main constituent elements (Li, Ni, Co, Mn, O). Examples of additive elements include transition metals or typical metals such as Mg, Ca, Al, Ti, V, Cr, Si, Y, Zr, Nb, Mo, Hf, Ta, W, Na, Fe, Zn, and Sn. Alternatively, additive elements may be half-metals such as B, C, Si, and P, or non-metals such as S, F, Cl, Br, and I. While detailed descriptions are omitted, this applies to other lithium transition metal composite oxides described as "~type composite oxides". Furthermore, the positive electrode active material layer 14 may also contain additives other than the positive electrode active material. Examples of such additives include conductive materials and binders. Specific examples of conductive materials include carbon materials such as acetylene black (AB). Specific examples of binders include resin binders such as polyvinylidene fluoride (PVdF). Moreover, when the total solid content of the positive electrode active material layer 14 is set to 100% by mass, the content of the positive electrode active material is approximately 80% by mass or more, typically 90% by mass or more.

[0060] On the other hand, the protective layer 16 is configured to have a lower conductivity than the positive electrode active material layer 14. By providing this protective layer 16 in the region adjacent to the end edge of the positive electrode plate 10, it is possible to prevent internal short circuits caused by direct contact between the positive electrode core 12 and the negative electrode active material layer 24 when the separator is damaged. For example, the protective layer 16 is preferably formed as a layer containing insulating ceramic particles. Examples of such ceramic particles include inorganic oxides such as alumina (Al2O3), magnesium oxide (MgO), silicon dioxide (SiO2), and titanium dioxide (TiO2); nitrides such as aluminum nitride and silicon nitride; metal hydroxides such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide; clay minerals such as mica, talc, boehmite, zeolite, apatite, and kaolin; and glass fibers. Considering insulation and heat resistance, alumina, boehmite, aluminum hydroxide, silicon dioxide, and titanium dioxide are preferred among the above. Alternatively, the protective layer 16 may also contain an adhesive for fixing the ceramic particles to the surface of the positive electrode core 12. Examples of such adhesives include resin adhesives such as polyvinylidene fluoride (PVdF). Furthermore, the protective layer is not a necessary component of the positive electrode plate. That is, in the energy storage device disclosed herein, a positive electrode plate without a protective layer can also be used.

[0061] (b) Negative electrode plate

[0062] like Figure 7 As shown, the negative electrode plate 20 (second electrode plate) is a long strip-shaped component. This negative electrode plate 20 includes a negative electrode core 22 as a strip-shaped metal foil and a negative electrode active material layer 24 applied to the surface of the negative electrode core 22. Furthermore, from the viewpoint of battery performance, the negative electrode active material layer 24 is preferably applied to both sides of the negative electrode core 22. Also, the negative electrode plate 20 has an end edge extending outward from one side in the winding axis direction (width direction Y). Figure 7 The negative electrode tab 22t protrudes from the right side of the negative electrode plate 20. Multiple negative electrode tabs 22t are provided at predetermined intervals along the length L of the negative electrode plate 20. These negative electrode tabs 22t represent the area where the negative electrode core 22 is exposed before the application of the negative electrode active material layer 24.

[0063] As components constituting the negative electrode plate 20, conventionally known materials that can be used in general energy storage devices (e.g., lithium-ion secondary batteries) can be used without particular limitation. For example, as the negative electrode core 22, a metallic material with a specified conductivity can be preferably used. This negative electrode core 22 is preferably made of, for example, copper or a copper alloy. On the other hand, the negative electrode active material layer 24 is a layer containing negative electrode active material. Hereinafter, the material of the negative electrode active material layer 24 will be described using a lithium-ion secondary battery as an example. However, the following description is not intended to limit the negative electrode plate of the electrode body disclosed herein.

[0064] As the negative electrode active material, a material capable of reversibly adsorbing and releasing charge carriers in relation to the aforementioned positive electrode active material is used. Furthermore, the specific material of the negative electrode active material is not particularly limited, and materials commonly used in conventional energy storage devices can be used without particular restriction. Examples of such negative electrode active materials include carbon materials and silicon-based materials. Examples of carbon materials include graphite, hard carbon, soft carbon, and amorphous carbon. Additionally, amorphous carbon-coated graphite with amorphous carbon coating on its surface can also be used. On the other hand, examples of silicon-based materials include silicon and silicon oxide (silicon dioxide). Furthermore, silicon-based materials may also contain other metallic elements (e.g., alkaline earth metals) or their oxides. Additionally, the negative electrode active material layer 24 may also contain additives other than the negative electrode active material. Examples of such additives include binders and thickeners. Specific examples of binders include rubber-based binders such as styrene-butadiene rubber (SBR). Specific examples of thickeners include carboxymethyl cellulose (CMC). Furthermore, when the total solid composition of the negative electrode active material layer 24 is set to 100% by mass, the content of the negative electrode active material is approximately 30% by mass or more, typically 50% by mass or more. Additionally, the negative electrode active material can account for 80% by mass or more, or even 90% by mass or more, of the negative electrode active material layer 24.

[0065] (c) diaphragm

[0066] like Figure 7 As shown, the electrode body 40 of this embodiment includes two separators (first separator 30A and second separator 30B). Each separator is an insulating sheet with multiple fine through holes through which charge carriers can pass. By sandwiching the first separator 30A and the second separator 30B between the positive electrode plate 10 and the negative electrode plate 20, contact between the positive electrode plate 10 and the negative electrode plate 20 can be prevented, and charge carriers (e.g., lithium ions) can move between the positive electrode plate 10 and the negative electrode plate 20. Furthermore, the material of the separator can be without particular limitation, using materials that are commonly used in separators of conventionally known energy storage devices. For example, the separator is preferably a porous sheet-like component containing a polyolefin resin, etc. This ensures sufficient flexibility of the separator, making it easy to manufacture (wound and stamped) the electrode body 40. Furthermore, as the polyolefin resin, polyethylene (PE), polypropylene (PP), or mixtures thereof can be used.

[0067] Furthermore, although details will be described later, in the technology disclosed herein, the electrode body 40 is disassembled by grasping and pulling the first diaphragm 30A and / or the second diaphragm 30B. Therefore, each diaphragm preferably uses a diaphragm with a certain or higher strength. From this viewpoint, the thickness of each diaphragm is preferably 5 μm or more, more preferably 8 μm or more, further preferably 10 μm or more, and particularly preferably 12 μm or more. On the other hand, the thickness of the diaphragm is preferably 30 μm or less, more preferably 25 μm or less, further preferably 20 μm or less, and particularly preferably 18 μm or less. As a result, the distance between the positive electrode plate 10 and the negative electrode plate 20 (inter-electrode distance) is shortened, and therefore, it is possible to construct an energy storage device 100 with excellent charge and discharge efficiency.

[0068] The first diaphragm 30A and the second diaphragm 30B will be described below. Figure 10 As shown, on the surface of the first diaphragm 30A facing the positive electrode plate 10 ( Figure 10 A first adhesive layer 34A is applied to the surface of the first diaphragm 30A facing the negative electrode plate 20. Thus, the first diaphragm 30A is bonded to the positive electrode plate 10 (first electrode plate). On the other hand, on the surface of the first diaphragm 30A facing the negative electrode plate 20... Figure 10 No adhesive layer is applied to the front F side of the second diaphragm 30B. Therefore, the first diaphragm 30A is not bonded to the negative electrode plate 20 (second electrode plate). Next, on the side of the second diaphragm 30B facing the negative electrode plate 20... Figure 10 A second adhesive layer 34B is applied to the surface of the second diaphragm 30B facing the Rr side. Thus, the second diaphragm 30B is bonded to the negative electrode plate 20 (the second electrode plate). Additionally, on the surface of the second diaphragm 30B facing the positive electrode plate 10... Figure 10 No adhesive layer was applied to the front F side of the membrane. Therefore, the second diaphragm 30B is not bonded to the positive electrode plate 10 (the first electrode plate).

[0069] Furthermore, the first adhesive layer 34A and the second adhesive layer 34B (hereinafter collectively referred to as "adhesive layers") are layers containing at least an adhesive resin. Examples of such adhesive resins include polyvinylidene fluoride (PVdF), acrylic resin, and styrene-butadiene rubber (SBR). This allows for proper bonding of the electrode plate and the diaphragm. Additionally, the adhesive layer of the electrode body disclosed herein may also contain inorganic particles. This allows the adhesive layer to have heat resistance and suppresses thermal shrinkage of the diaphragm when the temperature rises, thus contributing to improved safety of the energy storage device. Furthermore, examples of inorganic particles include ceramic particles containing alumina, silicon dioxide, titanium dioxide, boehmite, aluminum hydroxide, magnesium carbonate, magnesium oxide, zirconium oxide, zinc oxide, iron oxide, cerium oxide, yttrium oxide, etc., as main components. Furthermore, the content of the adhesive resin in the adhesive layer is preferably 10% by mass or more, more preferably 15% by mass or more, and particularly preferably 20% by mass or more. This allows for more appropriate bonding of the electrode plate and the diaphragm. On the other hand, if the adhesive layer has excessively strong adhesion, the fabrication of the electrode body (winding of each sheet component) may become difficult. From this perspective, the content of adhesive resin in the adhesive layer is preferably 40% by mass or less, more preferably 35% by mass or less, and particularly preferably 30% by mass or less. Furthermore, the aforementioned "content of adhesive resin" is the mass ratio of adhesive resin relative to the total mass of the adhesive layer.

[0070] (d) Wound construction

[0071] The specific winding structure of the electrode body 40 in this embodiment will be described below. First, as... Figure 9 As shown, when manufacturing the electrode body 40, each sheet member is wound with the ends of the first diaphragm 30A, the positive electrode plate 10, the second diaphragm 30B, and the negative electrode plate 20 aligned. As a result, inside the electrode body 40, the ends of the first diaphragm 30A (first starting end 30As), the positive electrode plate 10 (positive starting end 10s), the second diaphragm 30B (second starting end 30Bs), and the negative electrode plate 20 (negative starting end 20s) are arranged approximately aligned. However, in the disclosed technology, the position of the starting ends of each sheet member is not particularly limited. For example, even if the positions of the starting ends of each sheet member are different, the effect brought about by the disclosed technology (separation of the positive electrode plate 10 and the negative electrode plate 20) can be appropriately achieved.

[0072] On the other hand, in the electrode body 40 of this embodiment, the positions of the ends where the sheet members finish winding are different. First, in this embodiment, the length of the negative electrode plate 20 is set to be longer than that of the positive electrode plate 10. Therefore, as... Figure 9As shown near the curved portion 40r of the upper U in the diagram, the outermost negative electrode plate 20 is wound to cover the winding end (positive electrode terminal portion 10e) of the positive electrode plate 10. Furthermore, a region is formed near the winding end (negative electrode terminal portion 20e) of the negative electrode plate 20 that does not face the positive electrode plate 10. Therefore, the area of ​​the negative electrode plate 20 is larger than the area of ​​the positive electrode plate 10. As a result, the amount of Li ions that can be adsorbed in the negative electrode plate 20 is relatively large, thus suppressing the deposition of metallic Li in the negative electrode plate 20.

[0073] Next, the lengths of the first diaphragm 30A and the second diaphragm 30B are set to be longer than the pair of electrode plates (positive electrode plate 10 and negative electrode plate 20). Therefore, as Figure 9 As shown, the first diaphragm 30A extends from the positive electrode terminal 10e and is wound around the outer periphery of the electrode body 40. On the other hand, the second diaphragm 30B extends from the negative electrode terminal 20e and is wound around the outer periphery of the electrode body 40. That is, as... Figure 9 and Figure 10 As shown, in this embodiment, a diaphragm winding section 40s is formed on the outer periphery of the electrode body 40 (winding body), in which only the first diaphragm 30A and the second diaphragm 30B are wound. This protects the positive electrode plate 10 and the negative electrode plate 20 from external impacts, etc. Furthermore, the number of times the first diaphragm 30A and the second diaphragm 30B are wound in the diaphragm winding section 40s is not particularly limited.

[0074] Furthermore, in the electrode body 40 of this embodiment, a first diaphragm 30A is wound around the outermost periphery of the wound body. Here, as... Figure 8 As shown, the winding end (second terminal portion 30Be) of the second diaphragm 30B extends downwards from the winding end (first terminal portion 30Ae) of the first diaphragm 30A and protrudes onto the outer surface of the winding body (electrode body 40). Therefore, the first terminal portion 30Ae and the second terminal portion 30Be of the electrode body 40 in this embodiment can be visually identified from the outside. Consequently, when disassembling the electrode body 40, both the first terminal portion 30Ae of the first diaphragm 30A and the second terminal portion 30Be of the second diaphragm 30B can be easily grasped.

[0075] Here, as Figure 10As shown, in this embodiment, no adhesive layers (first adhesive layer 34A and second adhesive layer 34B) are applied to the first separator 30A and the second separator 30B in the separator winding section 40s. That is, the separator winding section 40s in this embodiment has a non-adhesive region 30X where the first separator 30A and the second separator 30B are not bonded. Moreover, this non-adhesive region 30X is formed in the first opposing portion F1 between the inner surface 30Aa of the first separator 30A and the outer surface 30Bb of the second separator 30B. In addition, the non-adhesive region 30X is also formed in the second opposing portion F2 between the outer surface 30Ab of the first separator 30A and the inner surface 30Ba of the second separator 30B. In other words, in this embodiment, the first separator 30A has the first adhesive layer 34A applied in the region facing the positive electrode plate 10. However, no adhesive layer was applied to the region of the first diaphragm 30A wound around the diaphragm winding portion 40s (from the first terminal portion 30Ae to the positive electrode terminal portion 10e). Figure 11 Similarly, a second adhesive layer 34B is applied to the second diaphragm 30B in the region facing the negative electrode plate 20. However, no adhesive layer is applied to the region of the second diaphragm 30B wound around the diaphragm winding portion 40s (the region from the second terminal portion 30Be to the negative electrode terminal portion 20e). Figure 11 The electrode body 40 of this structure can be easily unwound from the diaphragm winding 40s by simply holding the first terminal 30Ae and the second terminal 30Be and pulling it.

[0076] Next, as Figures 8-10 As shown, in this embodiment, a first adhesive tape 80 is attached to the outermost surface of the electrode body 40 (wound body) in a manner that spans both the first terminal portion 30Ae and the second terminal portion 30Be. This prevents the electrode body 40 from disintegrating during manufacturing or use. Furthermore, in this embodiment, a first peeling portion 82 is formed at the circumferential end of the first adhesive tape 80, which is not attached to the outermost surface of the wound body (electrode body 40). By grasping this first peeling portion 82 and pulling the first adhesive tape 80, the first adhesive tape 80 can be easily peeled off while suppressing damage to the diaphragm. This prevents damage to the first terminal portion 30Ae and the second terminal portion 30Be when peeling off the first adhesive tape 80. As a result, when unwinding the diaphragm winding portion 40s, the first terminal portion 30Ae and the second terminal portion 30Be can be properly grasped. Furthermore, the "peeling portion of the adhesive tape" in this specification can have various structures as long as it is not attached to the outermost surface of the electrode body. For example, the release portion can be formed by not applying adhesive to the ends of the adhesive tape. Alternatively, if adhesive is applied to the entire area of ​​one side of the adhesive tape, the ends of the tape can be folded so that the adhesives face each other. Even with this structure, an adhesive tape with a release portion can be formed.

[0077] Furthermore, in this embodiment, the first peeling portion 82 is provided in the circumferential direction ( Figure 8 The first adhesive tape 80 in the height direction Z) is located near the first terminal portion 30Ae at one of its two ends. Figure 8 The upper U) end of the membrane. According to this structure, it is possible to avoid reversing the winding direction of the diaphragm ( Figure 8 The first adhesive tape 80 is peeled off from the top (U) towards the bottom (D). This further appropriately suppresses damage to the first terminal portion 30Ae and the second terminal portion 30Be. Furthermore, this structure is not limited to the technology disclosed herein. By appropriately adjusting the adhesiveness of the first adhesive tape 80, the strength of the diaphragm, etc., even on the side closest to the second terminal portion 30Be (… Figure 8 When a first peeling portion is provided at the lower end of the middle (D), damage to the first terminal portion 30Ae and the second terminal portion 30Be can be sufficiently suppressed.

[0078] 2. Disassembly of the electrode body

[0079] When recovering valuable metals from the energy storage device 100 with the above-described structure, the energy storage device 100 is disassembled to remove the electrode body 40. Then, the electrode body 40 is disassembled to separate the positive electrode plate 10 and the negative electrode plate 20. This allows the positive electrode plate 10 and the negative electrode plate 20 to be provided to the regeneration process one by one, thus contributing to the efficiency of valuable metal recovery and the reduction of regeneration costs. The steps for separating the positive electrode plate 10 and the negative electrode plate 20 from the energy storage device 100 with the above-described structure will be described below.

[0080] First, when disassembling the energy storage device 100, it is preferable to discharge the battery and cut off the battery casing 50. This allows the charged energy storage device 100 (battery casing 50) to be safely disassembled. Then, the electrode body 40 is removed from the disassembled battery casing 50. At this time, as... Figure 5 As shown, the positive electrode tab group 42 of the electrode body 40 is connected to the positive second current collector 72. Therefore, it is preferable to disconnect either the positive electrode tab group 42 or the positive second current collector 72. Additionally, the negative electrode tab group 44 is connected to the negative second current collector 77. Therefore, it is preferable to disconnect either the negative electrode tab group 44 or the negative second current collector 77. This allows the electrode body 40 to be easily removed. Furthermore, the procedure for removing the electrode body 40 from the battery casing 50 is not particularly limited and can be appropriately modified depending on the structure of the energy storage device 100.

[0081] Next, in this embodiment, the electrode body 40 is disassembled to separate the positive electrode plate 10 and the negative electrode plate 20. Specifically, firstly, the first adhesive tape 80 is peeled off from the electrode body 40. At this time, by grasping the first peeling portion 82 and pulling, the first adhesive tape 80 can be easily peeled off while suppressing damage to the first diaphragm 30A and the second diaphragm 30B. Next, the first terminal portion 30Ae of the first diaphragm 30A and the second terminal portion 30Be of the second diaphragm 30B are grasped and pulled. At this time, in the diaphragm winding portion 40s of this embodiment, the opposing surfaces of the first diaphragm 30A and the second diaphragm 30B are not bonded. (In other words, in Figure 10 The first opposing portion F1 and the second opposing portion F2 are each provided with a non-adhesive region 30X. Therefore, the diaphragm winding portion 40s can be easily unwound by simply pulling the first terminal portion 30Ae and the second terminal portion 30Be respectively.

[0082] Furthermore, in this embodiment, the first separator 30A is bonded to the positive electrode plate 10, and the second separator 30B is bonded to the negative electrode plate 20. However, the first separator 30A is not bonded to the negative electrode plate 20, and the second separator 30B is not bonded to the positive electrode plate 10. Therefore, when the separator winding portion 40s is unwound, as... Figure 11 As shown, the electrode body 40 can be separated into a positive electrode plate 10 bonded to the first diaphragm 30A and a negative electrode plate 20 bonded to the second diaphragm 30B.

[0083] In this embodiment, the separated positive electrode plate 10 and negative electrode plate 20 are preferably calcined one by one. This removes the first separator 30A and the second separator 30B. As a result, the positive electrode plate 10 and negative electrode plate 20 can be recovered in a separated state. Then, by dissolving the calcined positive electrode plate 10 in a prescribed solution (acid, etc.), a metal solution containing only the metal components from the positive electrode plate 10 can be prepared. Valuable metals (Li, Ni, Co, Mn, etc.) usable in the manufacture of the positive electrode plate 10 can be easily extracted from this metal solution. Similarly, by dissolving the calcined negative electrode plate 20 in a solution, a metal solution containing only the metal components from the negative electrode plate 20 can be prepared. Valuable metals (Cu, etc.) usable in the manufacture of the negative electrode plate 20 can be easily extracted from this metal solution. As described above, according to this embodiment, a pair of electrode plates can be provided to the regeneration process one by one, thus contributing to the efficiency of valuable metal recovery and the reduction of regeneration costs.

[0084] <Other Implementation Methods>

[0085] The above describes one embodiment of the technology disclosed herein. Furthermore, the first embodiment described above illustrates an example of applying the technology disclosed herein and is not intended to limit the scope of the technology disclosed herein. Hereinafter, other embodiments of the technology disclosed herein will be described.

[0086] 1. Bonding of electrode plates to diaphragm

[0087] In the first embodiment, a positive electrode plate 10 is used as the electrode plate (first electrode plate) bonded to the first diaphragm 30A, and a negative electrode plate 20 is used as the electrode plate (second electrode plate) bonded to the second diaphragm 30B. However, the stacking order of the electrode plates is not a limiting factor of the technology disclosed herein. For example, the negative electrode plate may also be bonded to the first diaphragm (i.e., the diaphragm wound around the outermost periphery of the wound body). In this case, the positive electrode plate is bonded to the second diaphragm (the diaphragm wound around the opposite inner side). Even with this structure of electrode body, the technology disclosed herein can be applied.

[0088] 2. Specific bonding methods

[0089] Furthermore, in the first embodiment, adhesive layers are applied to the first separator 30A and the second separator 30B, respectively. However, the method of bonding the separator and the electrode plate is not particularly limited. For example, as described above, an adhesive is included in the positive electrode active material layer 14 and the negative electrode active material layer 24. If the adhesive is segregated on the surfaces of the positive electrode active material layer 14 and the negative electrode active material layer 24, an electrode plate with excellent surface adhesion can be obtained. Alternatively, a strip-shaped adhesive sheet can be inserted between the separator and the electrode plate. By using these methods, the separator and the electrode plate can be bonded even without applying an adhesive layer to the surface of the separator.

[0090] 3. The extent of the non-adhesive area

[0091] like Figure 10 As shown, in the first embodiment, non-adhesive regions 30X are formed on both the first opposing portion F1 and the second opposing portion F2. In other words, in the first embodiment, the first diaphragm 30A and the second diaphragm 30B are not adhered during the diaphragm winding portion 40s. However, the non-adhesive regions can be formed in at least one of the first opposing portion and the second opposing portion, and are not limited to the first embodiment described above. For example, in Figure 12 In the illustrated embodiment, a first adhesive layer 34A is provided in the first opposing portion F1, and no adhesive layer is provided in the second opposing portion F2. In other words, in Figure 12 In this configuration, a non-adhesive region 30X is formed only in the second opposing portion F2. With this structure, the electrode body 40 can unwind the diaphragm winding portion 40s along the second opposing portion F2, which has the non-adhesive region 30X, while maintaining adhesion in the first opposing portion F1. In this case, as... Figure 13 As shown, after the electrode body 40 is disassembled, on one side of the length direction ( Figure 13A laminate 40X is formed at the right end of the first diaphragm 30A and the second diaphragm 30B bonded together by a first adhesive layer 34A. Then, by removing this adhesive residue 30re, the positive electrode plate 10 bonded to the first diaphragm 30A and the negative electrode plate 20 bonded to the second diaphragm 30B can be separated. As described above, even if a non-bonded area is formed in either the first or second opposing portion, the pair of electrode plates can be properly separated.

[0092] Furthermore, in the first embodiment, the non-adhesive region is formed over the entire area of ​​the diaphragm winding portion in the winding direction. In other words, in the first embodiment, the first diaphragm 30A is not coated with the first adhesive layer 34A in the region from the first terminal portion 30Ae to the positive terminal portion 10e. Similarly, in the first embodiment, the second diaphragm 30B is not coated with the second adhesive layer 34B in the region from the second terminal portion 30Be to the negative terminal portion 20e. However, in the technology disclosed herein, the non-adhesive region only needs to extend inward in the winding direction from the first terminal portion of the first diaphragm and / or the second terminal portion of the second diaphragm. If a non-adhesive region is formed at the terminal portion of the diaphragm in this way, the terminal portion can be grasped when the diaphragm winding portion is unwound. In this case, even if there is a region where the diaphragms are bonded to each other at a position closer to the inside of the winding direction than the terminal portion, the bond between the diaphragms can be torn off by holding the terminal portion and pulling. As described above, if a non-adhesive region is formed by extending inward from the first terminal portion and / or the second terminal portion toward the winding direction, then even if there is adhesion between the diaphragms in other regions, a pair of electrode plates can be properly separated.

[0093] Furthermore, the non-adhesive region preferably extends 10 mm or more (more preferably 15 mm or more, particularly preferably 20 mm or more) from the first end portion of the first diaphragm (or the second end portion of the second diaphragm) toward the winding direction. This allows for easy gripping of the first end portion of the first diaphragm (or the second end portion of the second diaphragm). Additionally, the non-adhesive region is more preferably formed in an area representing 1% or more (more preferably 2% or more, particularly preferably 3% or more) of the total length of the first opposing portion (or the second opposing portion) in the winding direction. This further facilitates the unwinding of the diaphragm winding. On the other hand, there is no particular upper limit to the length of the non-adhesive region in the winding direction. When a non-adhesive region is formed over the entire area (100%) of the first opposing portion (or the second opposing portion) in the winding direction, as in the first embodiment, the diaphragm winding can be unwound particularly easily.

[0094] 4. Structure of non-bonded areas

[0095] Furthermore, in the first embodiment, a non-adhesive region is formed by forming a region on a portion of the diaphragm where no adhesive layer is applied. However, the non-adhesive region is not limited to the structure of the first embodiment, as long as it enables the first and second diaphragms to be non-adhesive. For example, when using a diaphragm with an adhesive layer applied to its entire length, a non-adhesive resin sheet can be adhered to the area where the non-adhesive region is to be formed. Even with this structure, a non-adhesive region can be formed in a predetermined area extending from the terminal portion.

[0096] 5. Adhesive tape

[0097] Furthermore, in the first embodiment, a first adhesive tape 80 is attached to the outer peripheral surface of the electrode body 40. However, from the viewpoint of further facilitating the disassembly of the electrode body 40 in the disclosed technology, adhesive tape other than the aforementioned first adhesive tape 80 may also be attached. For example, such as Figure 14 As shown, when a non-adhesive area is provided in the region including the first terminal portion 30Ae (the first opposing portion), it is preferable to adhere the second adhesive tape 80A, which crosses the first terminal portion 30Ae but does not cross the second terminal portion 30Be, to the outermost surface of the wound body. In this case, when along the winding direction ( Figure 14 When the second adhesive tape 80A is peeled off from below (D) towards above (U), the first end portion 30Ae is pulled as the second adhesive tape 80A is peeled off. This allows the diaphragm winding portion to be easily unwound along the first opposing portion. Furthermore, the second adhesive tape 80A is preferably circumferentially (…). Figure 14 The end of the two ends in the height direction Z that faces the second diaphragm 30B (in the height direction Z) Figure 14 The lower end of D in the winding has a second peeling portion 82A that is not attached to the outermost surface of the winding. This allows for easy peeling along the winding direction ( Figure 14 Peel the second adhesive tape 80A from the bottom (D) towards the top (U).

[0098] In addition, such as Figure 15 As shown, when a non-adhesive area is provided in the region including the second terminal portion 30Be (the second opposing portion), it is preferable to adhere the third adhesive tape 80B, which crosses the second terminal portion 30Be but does not cross the first terminal portion 30Ae, to the outermost surface of the wound body. In this case, when along the winding direction ( Figure 15 When the third adhesive tape 80B is peeled off from below (D) towards above (U), the second end portion 30Be is pulled along as the third adhesive tape 80B is peeled off. This allows the diaphragm winding to be easily unwound along the second opposing portion. Furthermore, the third adhesive tape 80B is preferably located at the end opposite to the first diaphragm 30A (…). Figure 15A third peeling portion 82B is formed at the lower end (D) of the winding body, which is not attached to the outermost surface of the winding body. As a result, the third adhesive tape 80B can be easily peeled off from the lower D toward the upper U.

[0099] Furthermore, when non-adhesive regions are provided on both sides, including the region containing the first terminal portion 30Ae (first opposing portion) and the region containing the second terminal portion 30Be (second opposing portion), such as Figure 16 As shown, it is preferable to adhere both the second adhesive tape 80A and the third adhesive tape 80B. This allows the separator winding to be easily unwound along the first and second opposing portions respectively, thus making it easier to separate the positive and negative plates.

[0100] Additionally, the second and third adhesive tapes can be integrated with the first adhesive tape. Specifically, in Figure 17 In the illustrated configuration, a first adhesive tape 80 is attached across both the first terminal portion 30Ae and the second terminal portion 30Be. A first peeling portion 82 is formed at the upper end of the first adhesive tape 80 (the end facing the first terminal portion 30Ae). Furthermore, a dotted line 84 is formed on the first adhesive tape 80, surrounding the area that crosses the second terminal portion 30Be but not the first terminal portion 30Ae. A third peeling portion 82B is formed at the lower end of the area surrounded by the dotted line 84 (the end facing the first diaphragm 30A). When unwinding the electrode body 40, the first adhesive tape 80 is first grasped by the first peeling portion 82 and peeled off from the top U towards the bottom D. At this time, the first adhesive tape 80 breaks along the dotted line 84. As a result, a third adhesive tape 80B, crossing the second terminal portion 30Be but not the first terminal portion 30Ae, is formed on the surface of the electrode body 40 after the first adhesive tape 80 has been peeled off. Then, by grasping the third peeling part 82B and peeling the third adhesive tape 80B upwards, the diaphragm winding in the region (second opposing part) containing the second terminal part 30Be can be easily unwound.

[0101] The technology disclosed herein has been described in detail above, but these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes technologies obtained by various modifications and alterations to the specific examples described above. That is, the technology disclosed herein includes the methods described in items 1 to 8 below.

[0102] <Project 1>

[0103] An electrode body, wherein the electrode body comprises:

[0104] The first electrode plate is in the shape of a strip;

[0105] The first septum is in the shape of a band;

[0106] The strip-shaped second electrode plate; and

[0107] The second septum is in the shape of a band.

[0108] The electrode body is a wound body formed by winding the first electrode plate and the second electrode plate together with the first diaphragm and the second diaphragm in between.

[0109] The first diaphragm is bonded to the first electrode plate but not to the second electrode plate.

[0110] The second diaphragm is bonded to the second electrode plate, but not to the first electrode plate.

[0111] A diaphragm winding portion is formed on the outer periphery of the wound body, in which only the first diaphragm and the second diaphragm are wound, and the first diaphragm is wound on the outermost periphery of the diaphragm winding portion.

[0112] The second terminal portion, which serves as the winding end of the second diaphragm, extends from the first terminal portion, which serves as the winding end of the first diaphragm, and protrudes to the outer surface of the wound body.

[0113] The diaphragm winding portion has at least one of a first opposing portion between the inner side of the first diaphragm and the outer side of the second diaphragm, and a second opposing portion between the outer side of the first diaphragm and the inner side of the second diaphragm, having a non-adhesive region where the first diaphragm and the second diaphragm are not bonded.

[0114] The non-adhesive region extends from the first terminal portion and / or the second terminal portion toward the inside in the winding direction.

[0115] A first adhesive tape is attached to the outermost surface of the wound body, spanning both the first terminal portion and the second terminal portion. At least one of the two ends of the first adhesive tape in the circumferential direction has a first peel portion that is not attached to the outermost surface of the wound body.

[0116] <Project 2>

[0117] In the electrode body described in Project 1

[0118] The first peeling portion is formed at one end near the first terminal portion.

[0119] <Project 3>

[0120] In the electrode body described in Project 1 or 2

[0121] The non-adhesive area is provided in the region including the first terminal portion.

[0122] A second adhesive tape is attached to the outermost surface of the wound body, which extends across the first terminal portion but does not extend across the second terminal portion.

[0123] <Project 4>

[0124] In the electrode body described in Project 3

[0125] A second peeling portion is formed at one end of the second adhesive tape in the circumferential direction that faces the second diaphragm, and is not attached to the outermost surface of the wound body.

[0126] <Project 5>

[0127] In any one of items 1 to 4, the electrode body

[0128] The non-adhesive area is provided in the region containing the second terminal portion.

[0129] A third adhesive tape is attached to the outermost surface of the wound body, which extends across the second terminal portion but does not extend across the first terminal portion.

[0130] <Project 6>

[0131] In the electrode body described in Project 5

[0132] A third peeling portion is formed at one end of the third adhesive tape in the circumferential direction, on the side facing the first diaphragm, which is not attached to the outermost surface of the winding.

[0133] <Project 7>

[0134] In any one of items 1 to 6, the electrode body

[0135] The non-adhesive region is formed over the entire area of ​​the diaphragm winding portion on both the first opposing portion and the second opposing portion.

[0136] <Project 8>

[0137] An energy storage device, wherein the energy storage device comprises:

[0138] Electrode body; and

[0139] A battery casing that houses the electrodes.

[0140] The electrode body is any one of items 1 to 7.

[0141] Explanation of reference numerals in the attached figures

[0142] 10 Positive electrode plate

[0143] 10e Positive terminal section

[0144] 10s Positive electrode start end

[0145] 20 Negative electrode plate

[0146] 20e Negative terminal section

[0147] 20s negative electrode start end

[0148] 30A First Diaphragm

[0149] 30Ae First Terminal Department

[0150] 30As First Start End

[0151] 30B Second Diaphragm

[0152] 30Be Second Terminal

[0153] 30Bs second starting end

[0154] 30X Non-bonded Area

[0155] 30re adhesive residue

[0156] 34A First Adhesive Layer

[0157] 34B Second Adhesive Layer

[0158] 40 Electrode Body

[0159] 40X stack

[0160] 40s Diaphragm winding section

[0161] 50 Battery casing

[0162] 80 First adhesive tape

[0163] 80A Second Adhesive Tape

[0164] 80B Third Adhesive Tape

[0165] 82 First stripping section

[0166] 82A Second Stripping Section

[0167] 82B Third Stripping Section

[0168] 84 points broken line

[0169] 100 Storage devices

[0170] F1 First Phase

[0171] F2 Second phase.

Claims

1. An electrode body, wherein, The electrode body comprises: The first electrode plate is in the shape of a strip; The first septum is in the shape of a band; The strip-shaped second electrode plate; as well as The second septum is in the shape of a band. The electrode body is a wound body formed by winding the first electrode plate and the second electrode plate together with the first diaphragm and the second diaphragm in between. The first diaphragm is bonded to the first electrode plate but not to the second electrode plate. The second diaphragm is bonded to the second electrode plate, but not to the first electrode plate. A diaphragm winding portion is formed on the outer periphery of the wound body, in which only the first diaphragm and the second diaphragm are wound, and the first diaphragm is wound on the outermost periphery of the diaphragm winding portion. The second terminal portion, which serves as the winding end of the second diaphragm, extends from the first terminal portion, which serves as the winding end of the first diaphragm, and protrudes to the outer surface of the wound body. The diaphragm winding portion has at least one of a first opposing portion between the inner side of the first diaphragm and the outer side of the second diaphragm, and a second opposing portion between the outer side of the first diaphragm and the inner side of the second diaphragm, having a non-adhesive region where the first diaphragm and the second diaphragm are not bonded. The non-adhesive region extends from the first terminal portion and / or the second terminal portion toward the inside in the winding direction. A first adhesive tape is attached to the outermost surface of the wound body, spanning both the first terminal portion and the second terminal portion. At least one of the two ends of the first adhesive tape in the circumferential direction has a first peel portion that is not attached to the outermost surface of the wound body.

2. The electrode body according to claim 1, wherein, The first peeling portion is formed at one end near the first terminal portion.

3. The electrode body according to claim 1, wherein, The non-adhesive area is provided in the region including the first terminal portion. A second adhesive tape is attached to the outermost surface of the wound body, which extends across the first terminal portion but does not extend across the second terminal portion.

4. The electrode body according to claim 3, wherein, A second peeling portion is formed at one end of the second adhesive tape in the circumferential direction that faces the second diaphragm, and is not attached to the outermost surface of the wound body.

5. The electrode body according to claim 1, wherein, The non-adhesive area is provided in the region containing the second terminal portion. A third adhesive tape is attached to the outermost surface of the wound body, which extends across the second terminal portion but does not extend across the first terminal portion.

6. The electrode body according to claim 5, wherein, A third peeling portion is formed at one end of the third adhesive tape in the circumferential direction, on the side facing the first diaphragm, which is not attached to the outermost surface of the winding.

7. The electrode body according to any one of claims 1 to 6, wherein, The non-adhesive region is formed over the entire area of ​​the diaphragm winding portion on both the first opposing portion and the second opposing portion.

8. An energy storage device, wherein, The energy storage device includes: Electrode body; and A battery casing that houses the electrodes. The electrode body is the electrode body according to claim 1.

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