Energy storage device and method for manufacturing the same

Abstract

To provide an energy storage device with high conductivity. [Solution] The present invention provides a method for manufacturing an energy storage device comprising an electrode body 20, a case, first electrode terminals 30 and 40 attached to the bottom wall 12a of the case, and a spacer 80 disposed between the bottom wall 12a and the electrode body 20. This manufacturing method includes an assembly step of integrating the first current collectors 50 and 60 attached to the electrode body 20 with the spacer 80, an insertion step of inserting the electrode body 20, which is integrated with the spacer 80, into the inside of the case body 12, and a joining step of joining the first current collectors 50 and 60 and the first electrode terminals 30 and 40.

Description

Technical Field

[0001] The present invention relates to a power storage device and a method for manufacturing the same.

Background Art

[0002] Patent Document 1 discloses a power storage device including an electrode body including a first electrode and a second electrode, a case accommodating the electrode body, and a first electrode terminal electrically connected to the first electrode and attached to the bottom wall of the case. Patent Document 1 describes that an electrode tab (first current collector member) provided on the first electrode is joined to the first electrode terminal in the case by welding or the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the first electrode terminal is attached to the bottom wall of the case, it is difficult to stably abut both members in the case when joining the first current collector member and the first electrode terminal, and there is a problem that the difficulty of joining increases. Therefore, it is required to stably join the first current collector member and the first electrode terminal to provide a power storage device with high conduction reliability.

[0005] The present invention has been made in view of the above circumstances, and its main object is to provide a power storage device with high conduction reliability.

Means for Solving the Problems

[0006] The present invention provides a method for manufacturing an energy storage device, comprising: an electrode body including a first electrode and a second electrode; a case housing the electrode body; and a first electrode terminal electrically connected to the first electrode via a first current collector, wherein the case comprises a bottomed cylindrical case body having a bottom wall, a side wall provided on the outer peripheral edge of the bottom wall, and an opening facing the bottom wall; and a sealing plate that seals the opening of the case body, wherein the first electrode terminal is attached to the bottom wall of the case body, and further comprises a spacer disposed between the bottom wall and the electrode body, the assembly step of arranging the spacer at one end of the electrode body to which the first current collector is attached and integrating the first current collector with the spacer, an insertion step of inserting the electrode body, which is integrated with the spacer, into the case body from the one end, and a joining step of joining the first current collector and the first electrode terminal after the insertion step.

[0007] According to the method described above, the first current collector and the first electrode terminal can be stably joined, improving the conductivity reliability of the joint. Consequently, a highly reliable energy storage device can be realized. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic perspective view showing an energy storage device according to one embodiment. [Figure 2] Figure 2 is a schematic longitudinal cross-sectional view along the line II-II in Figure 1. [Figure 3] Figure 3 is a magnified view of the main part of Figure 2. [Figure 4] Figure 4 is a schematic longitudinal cross-sectional view along the line IV-IV in Figure 1. [Figure 5] Figure 5 is a schematic diagram showing the configuration of the electrode body. [Figure 6] Figure 6 is a schematic exploded perspective view showing the combined object. [Figure 7] Figure 7A is a schematic plan view of the spacer, and Figure 7B is a schematic perspective view of the spacer. [Figure 8] Figure 8A is an explanatory diagram of the insertion process, and Figure 8B is a magnified view of the area near the positive terminal, which is a key part. [Figure 9] Figure 9 is an explanatory diagram of the joining process. [Figure 10] Figure 10 is an explanatory diagram of the assembly process according to the first modified example. [Figure 11] Figure 11 is an explanatory diagram of the assembly process related to the second modified example. [Figure 12] Figure 12 is a magnified view of the vicinity of the positive terminal in a modified example. [Modes for carrying out the invention]

[0009] Hereinafter, several preferred embodiments of the technology disclosed herein will be described with reference to the drawings. Matters other than those specifically mentioned herein but necessary for carrying out the technology disclosed herein (e.g., general configuration and manufacturing processes of energy storage devices that do not characterize the technology disclosed herein) can be understood as design matters for those skilled in the art based on the prior art. The technology disclosed herein can be carried out based on the content disclosed herein and common technical knowledge in the art. Furthermore, the notation "A to B" indicating a range herein encompasses not only the meaning of "A or greater and B or less," but also the meanings of "greater than A" and "less than B."

[0010] [Energy storage device] Figure 1 is a schematic perspective view showing a power storage device 100 according to one embodiment. Figure 2 is a schematic longitudinal cross-sectional view along line II-II in Figure 1. Figure 3 is a partial enlarged view of the main part of Figure 2. Figure 4 is a schematic longitudinal cross-sectional view along line IV-IV in Figure 1. In the following description, the symbols L, R, F, Rr, U, and D in the drawings indicate left, right, front, back, top, and bottom. Also, the symbol X in the drawings indicates the short side direction (thickness direction) of the power storage device 100, the symbol Y indicates the long side direction of the power storage device 100 perpendicular to the short side direction, and the symbol Z indicates the vertical direction of the power storage device 100. The vertical direction Z may coincide with the vertical direction. However, these are merely directions for the convenience of explanation and do not limit the installation configuration of the power storage device 100 in any way.

[0011] In this specification, "energy storage device" refers to any device capable of repeated charging and discharging through the movement of charge carriers between a positive electrode and a negative electrode via an electrolyte. The electrolyte may be a liquid electrolyte, a gel electrolyte, or a solid electrolyte. The term "energy storage device" encompasses not only secondary batteries such as lithium-ion secondary batteries and nickel-metal hydride secondary batteries, but also capacitors that utilize chemical reactions, such as lithium-ion capacitors and pseudocapacitance capacitors.

[0012] As shown in Figure 2, the energy storage device 100 comprises a case 10, an electrode body 20, a positive electrode terminal 30, a negative electrode terminal 40, a positive electrode current collector 50, a negative electrode current collector 60, and a spacer 80. The energy storage device 100 further comprises a liquid electrolyte (electrolyte, not shown). The energy storage device 100 is a non-aqueous electrolyte secondary battery. Preferably, the energy storage device 100 is a secondary battery such as a lithium-ion secondary battery.

[0013] Case 10 is a housing that houses the electrode body 20. As shown in FIG. 1, the case 10 has an outer shape that is flat, bottomed, and rectangular parallelepiped (angular) here. The material of the case 10 may be the same as those conventionally used, and there is no particular limitation. The case 10 is preferably made of metal, and more preferably made of, for example, aluminum, aluminum alloy, iron, iron alloy, etc. As shown in FIG. 2, the case 10 includes a case body 12 and a sealing plate (lid body) 14. The case 10 (the case body 12 and the sealing plate 14) has a size corresponding to the size of the electrode body 20, the number of housed (one or more), etc.

[0014] The case body 12 is a bottomed cylindrical shape having a bottom wall, a side wall provided on the outer peripheral edge of the bottom wall, and an opening facing the bottom wall. The case body 12 is a bottomed and angular container having an opening 12h on the upper surface here. Specifically, as shown in FIG. 1, the case body 12 includes a substantially rectangular bottom wall 12a (first wall) having long sides and short sides, a pair of long side walls 12b (second wall and third wall) extending from the long side of the bottom wall 12a and facing each other, a pair of short side walls 12c (fourth wall and fifth wall) extending from the short side of the bottom wall 12a and facing each other, and an opening 12h (see FIG. 2) facing the bottom wall 12a. The case body 12 is preferably a bottomed angular cylindrical shape. The opening 12h is substantially rectangular here. The bottom wall 12a constitutes the lower surface of the case 10.

[0015] In addition, in this specification, the term "substantially rectangular" includes, in addition to a perfect rectangular shape (rectangular shape), for example, a shape in which the corners connecting the long side and the short side of the rectangular shape are rounded into an R shape, a shape having a notch at the corner, etc.

[0016] The long side wall 12b has a larger area than the short side wall 12c. In the present embodiment, the long side wall 12b and the short side wall 12c are each formed continuously from the outer peripheral edge of the bottom wall 12a. In other words, the boundary portion between the bottom wall 12a and the long side wall 12b is not a welded portion (not welded and joined), but a bent portion. Similarly, the boundary portion between the bottom wall 12a and the short side wall 12c is not a welded portion (not welded and joined), but a bent portion. The case body 12 having such a shape can be formed, for example, by deep drawing a single metal plate. The long side wall 12b and the short side wall 12c are an example of the "side wall".

[0017] The sealing plate 14 is attached to the case body 12 so as to seal the opening 12h of the case body 12. The sealing plate 14 is typically a plate-like member. The sealing plate 14 faces the bottom wall 12a of the case body 12. The sealing plate 14 is substantially rectangular here. The sealing plate 14 constitutes the upper surface of the case 10. The case 10 is integrated by joining (for example, welding and joining) the sealing plate 14 to the peripheral edge of the opening 12h of the case body 12. As shown in FIG. 2, a joining portion (for example, a welding and joining portion) 10w is formed at the fitting portion between the case body 12 and the sealing plate 14. Thereby, the case 10 is hermetically sealed.

[0018] As shown in FIG. 2, a gas discharge valve 17, lead-out holes 18 and 19, an electrolytic solution injection hole, 15 (also see FIG. 3), and a protrusion 12p (also see FIG. 4) are provided in the bottom wall 12a of the case body 12. The gas discharge valve 17 is a thin-walled portion configured to break when the pressure in the case 10 reaches or exceeds a predetermined value and discharge the gas in the case 10 to the outside. Note that the gas discharge valve 17 may be provided on the sealing plate 14. The lead-out holes 18 and 19 are formed at both ends in the long side direction Y of the bottom wall 12a, respectively. The lead-out holes 18 and 19 penetrate the bottom wall 12a. A positive electrode current collecting member 50 (specifically, a shaft portion 52 described later) and a negative electrode current collecting member 60 (specifically, a shaft portion 62 described later) are inserted through the lead-out holes 18 and 19, respectively.

[0019] The electrolyte injection hole 15 is a through-hole for injecting electrolyte into the case 10 after the sealing plate 14 has been assembled to the case body 12. As shown in Figures 2 and 3, the electrolyte injection hole 15 is sealed by inserting a sealing plug 16p after the electrolyte has been injected, and then joining (e.g., welding) a sealing plug cover 16c (sealing cap) to the periphery of the electrolyte injection hole 15. The sealing plug 16p is preferably made of resin. The sealing plug cover 16c is preferably made of metal, and more preferably made of aluminum or an aluminum alloy. The sealing plug 16p and the sealing plug cover 16c may be an integral part or separate parts. The electrolyte injection hole 15 may also be provided in the sealing plate 14.

[0020] The sealing plug 16p is longer in the vertical Z direction than the electrolyte injection hole 15 provided in the bottom wall 12a, and as shown in Figure 3, it protrudes onto the inner surface side of the bottom wall 12a. The portion of the sealing plug 16p that protrudes onto the inner surface side is housed in the electrolyte injection through hole 81 of the spacer 80, which will be described later. The tip of the sealing plug 16p (upper end in Figure 3) is positioned inside the electrolyte injection through hole 81 of the spacer 80. The sealing plug cover 16c is positioned to cover the sealing plug 16p from the outer surface side of the bottom wall 12a. The sealing plug cover 16c is positioned inside the recess 15b provided to surround the electrolyte injection hole 15. This makes it possible to better suppress interference between the joint between the bottom wall 12a and the sealing plug 16p and other members, which can cause damage or breakage to the joint.

[0021] As shown in Figure 4, the projection 12p is provided on the inner surface of the bottom wall 12a. The projection 12p is a protruding portion (convex portion) that protrudes from the inner surface side (electrode body 20 side) of the bottom wall 12a. The projection 12p is the portion that is inserted into the hole 87 of the spacer 80, as described later, in the insertion step (step 4) of the manufacturing method described later. From the viewpoint of improving insertability into the hole 87, it is preferable that the diameter of the projection 12p gradually decreases toward the tip (as it moves away from the bottom wall 12a). In other words, it is preferable that it has a tapered shape. The projection 12p can function as a positioning member for guiding the spacer 80 and the current collector (positive electrode current collector 50 and / or negative electrode current collector 60) to a desired position. From the viewpoint of improving positioning accuracy, it is preferable that there are multiple projections 12p (two or more, for example, an even number), as shown in Figure 1. It is preferable that the multiple projections 12p are located at a pair of diagonal corners of the bottom wall 12a.

[0022] The electrode body 20 is housed inside the case 10. The number of electrode bodies 20 housed in one case 10 is not particularly limited; there may be one or multiple (for example, two or more, three or more). As will be described later, in this embodiment, multiple (specifically two) electrode bodies 20 are housed inside one case 10 (see Figure 6).

[0023] As shown in Figure 2, the electrode body 20 is placed inside the case 10, covered by an electrode body holder 29 made of a resin sheet. This prevents the electrode body 20 from coming into direct contact with the case body 12. The material of the electrode body holder 29 can be the same as that used conventionally, and there are no particular restrictions. Examples of such materials include polyolefin resins such as polypropylene (PP) and polyethylene (PE), and fluororesins such as perfluoroalkoxyalkanes and polytetrafluoroethylene (PTFE).

[0024] Figure 5 is a schematic diagram showing the configuration of the electrode body 20. In Figure 5, the symbol LD indicates the longitudinal direction of the electrode body 20, which is manufactured in a strip shape. The symbol WD is a direction approximately perpendicular to the longitudinal direction LD and indicates the winding axis direction of the electrode body 20.

[0025] As shown in Figure 5, the electrode body 20 includes a positive electrode 22 and a negative electrode 24. In this embodiment, the electrode body 20 is a wound electrode body constructed by stacking a strip-shaped positive electrode 22 and a strip-shaped negative electrode 24 insulated from two strip-shaped separators 26, and winding them in the longitudinal direction LD around a winding axis WL. However, the electrode body 20 may also be a laminated electrode body in which multiple rectangular positive electrodes and multiple rectangular negative electrodes are stacked in an insulated state. In this embodiment, the electrode body 20 has a flattened outer shape. In this embodiment, the electrode body 20 is housed inside the case 10 such that the winding axis WL substantially coincides with the vertical direction Z. One of the positive electrode 22 and the negative electrode 24 is an example of a "first electrode," and the other is an example of a "second electrode."

[0026] As shown in Figure 5, the positive electrode 22 comprises a strip-shaped positive electrode current collector 22c and a positive electrode active material layer 22a fixed to at least one surface (preferably both sides) of the positive electrode current collector 22c. The positive electrode 22 here further comprises a positive electrode protective layer 22p. However, the positive electrode protective layer 22p is not essential and can be omitted in other embodiments. The components constituting the positive electrode 22 can be made of conventionally known materials that can be used in general energy storage devices (e.g., lithium-ion secondary batteries) without particular limitation. The positive electrode current collector 22c is preferably made of a conductive metal such as aluminum, aluminum alloy, nickel, or stainless steel, and here it is a metal foil, specifically aluminum foil. However, as described in the modified example (1-1) below, the positive electrode current collector 22c may have an insulating core (e.g., a resin layer).

[0027] As shown in Figure 5, the positive electrode 22 has a plurality of positive electrode tabs 22t on one end side in the winding axis direction WD. The plurality of positive electrode tabs 22t are provided at predetermined intervals (intermittently) along the longitudinal direction LD. The number of positive electrode tabs 22t attached to one electrode body 20 can be several tens or more, for example, about 40 to 60. Each of the plurality of positive electrode tabs 22t is convex and protrudes outward (to the left side in Figure 5). The plurality of positive electrode tabs 22t are identical in shape and are each approximately rectangular. However, the plurality of positive electrode tabs 22t may differ in size and shape from one another. The positive electrode tabs 22t are provided integrally with the positive electrode 22. The positive electrode tabs 22t are regions in the positive electrode current collector 22c where the positive electrode active material layer 22a is not formed. The positive electrode current collector 22c is exposed in at least a part of the positive electrode tabs 22t. However, as described in the modified example (1-2) below, the positive electrode tab 22t may be a different component from the positive electrode 22.

[0028] Multiple positive electrode tabs 22t are stacked at one end of the electrode body 20 in the winding axis direction WD, forming a positive electrode tab group 27 (see Figure 2). As shown in Figure 2, the tip of the positive electrode tab group 27 (lower end in Figure 2) is connected (more specifically, joined) to the positive electrode current collector 50. The positive electrode 22 is electrically connected to the positive electrode terminal 30 via the positive electrode tab group 27 (multiple positive electrode tabs 22t) and the positive electrode current collector 50. Preferably, the positive electrode 22 is electrically connected to the positive electrode current collector 50 via the positive electrode tab group 27.

[0029] As shown in Figure 5, the positive electrode active material layer 22a is provided in a strip shape along the longitudinal direction LD of the positive electrode current collector 22c. The positive electrode active material layer 22a contains a positive electrode active material (for example, a lithium transition metal composite oxide such as lithium nickel cobalt manganese composite oxide) that can reversibly intercept and release charge carriers. The positive electrode active material layer 22a may also contain optional components other than the positive electrode active material, such as conductive materials, binders, and various additives.

[0030] As shown in Figure 5, the positive electrode protective layer 22p is provided in a strip shape along the longitudinal direction LD of the positive electrode current collector 22c. The positive electrode protective layer 22p is provided at the boundary between the positive electrode current collector 22c and the positive electrode active material layer 22a in the winding axis direction WD. The positive electrode protective layer 22p contains an insulating inorganic filler (for example, ceramic particles such as alumina). The positive electrode protective layer 22p may also contain optional components other than the inorganic filler, such as a binder, conductive material, and various additive components. By providing the positive electrode protective layer 22p, it is possible to prevent the positive electrode 22 from directly contacting the negative electrode active material layer 24a and causing an internal short circuit in the energy storage device 100 when the separator 26 is damaged.

[0031] As shown in Figure 5, the negative electrode 24 comprises a strip-shaped negative electrode current collector 24c and a negative electrode active material layer 24a fixed to at least one surface (preferably both sides) of the negative electrode current collector 24c. The components constituting the negative electrode 24 can be made of conventionally known materials that can be used in general energy storage devices (e.g., lithium-ion secondary batteries) without particular limitations. The negative electrode current collector 24c is preferably made of a conductive metal such as copper, copper alloy, nickel, or stainless steel, and in this case, a metal foil, specifically a copper foil. However, as described in the modified example (1-1) below, the negative electrode current collector 24c may have an insulating core (e.g., a resin layer).

[0032] As shown in Figure 5, the negative electrode 24 has multiple negative electrode tabs 24t on one end in the winding axis direction WD. In the winding axis direction WD, the negative electrode tabs 24t are provided on the same side (left side in Figure 5) as the positive electrode tabs 22t. The multiple negative electrode tabs 24t are provided at predetermined intervals (intermittently) along the longitudinal direction LD. The number of negative electrode tabs 24t attached to one electrode body 20 is approximately the same as the number of positive electrode tabs 22t, and can be several tens or more. Each of the multiple negative electrode tabs 24t is convex and protrudes outward (left side in Figure 5). The multiple negative electrode tabs 24t are identical in shape and are approximately rectangular. However, the multiple negative electrode tabs 24t may differ in size and shape from one another. The negative electrode tabs 24t are provided integrally with the negative electrode 24. The negative electrode tab 24t is a region in the negative electrode current collector 24c where the negative electrode active material layer 24a is not formed. At least a portion of the negative electrode tab 24t exposes the negative electrode current collector 24c. However, as described in the modified example (1-2) below, the negative electrode tab 24t may be a separate component from the negative electrode 24.

[0033] Multiple negative electrode tabs 24t are stacked at one end of the electrode body 20 in the winding axis direction WD, forming a negative electrode tab group 28 (see Figure 2). As shown in Figure 2, the tip of the negative electrode tab group 28 (lower end in Figure 2) is connected (more specifically, joined) to the negative electrode current collector 60. The negative electrode 24 is electrically connected to the negative electrode terminal 40 via the negative electrode tab group 28 (multiple negative electrode tabs 24t) and the negative electrode current collector 60. Preferably, the negative electrode 24 is electrically connected to the negative electrode current collector 60 via the negative electrode tab group 28. Preferably, the electrode body 20 has a positive electrode tab group 27 and a negative electrode tab group 28 at one end.

[0034] As shown in Figure 5, the negative electrode active material layer 24a is provided in a strip shape along the longitudinal direction LD of the negative electrode current collector 24c. The negative electrode active material layer 24a contains a negative electrode active material (for example, a carbon material such as graphite, or a silicon material) that can reversibly absorb and release charge carriers. The negative electrode active material layer 24a may also contain optional components other than the negative electrode active material, such as a binder, a dispersant, or various additives.

[0035] As shown in Figure 5, the separator 26 is a component that insulates the positive electrode active material layer 22a of the positive electrode 22 and the negative electrode active material layer 24a of the negative electrode 24. For the separator 26, a porous sheet made of polyolefin resin such as polyethylene (PE) or polypropylene (PP) is preferred. The separator 26 may have a base material portion made of a porous sheet made of resin and a functional layer (e.g., a heat resistance layer (HRL) or adhesive layer) formed on at least one surface of the base material portion. The heat resistance layer is typically a layer containing an inorganic filler and a binder. Examples of inorganic fillers include alumina, boehmite, aluminum hydroxide, and titania. Here, the separator 26 constitutes the outer surface (outermost periphery) of the electrode body 20.

[0036] As the liquid electrolyte (electrolyte), any electrolyte that can be used in general energy storage devices (e.g., lithium-ion secondary batteries) can be used without particular limitations. One example is a non-aqueous electrolyte obtained by dissolving a support salt in a non-aqueous solvent. Examples of non-aqueous solvents include carbonate-based solvents such as ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate. Examples of support salts include lithium salts such as LiPF6 and sodium salts such as NaPF6. The electrolyte may contain additives as needed. However, in other embodiments, the electrolyte may be in solid form (solid electrolyte) and integrated with the electrode body 20.

[0037] As shown in Figures 1 and 2, the positive terminal 30 and the negative terminal 40 are attached to the bottom wall 12a of the bottomed cylindrical case body 12, respectively. The positive terminal 30 is attached to one end of the long side direction Y of the bottom wall 12a (the right end in Figures 1 and 2), specifically to the periphery of the lead hole 18. The negative terminal 40 is attached to the other end of the long side direction Y of the bottom wall 12a (the left end in Figures 1 and 2), specifically to the periphery of the lead hole 19. It is preferable that both the positive terminal 30 and the negative terminal 40 are attached to the bottom wall 12a. However, in other embodiments, the bottom wall 12a may also serve as one of the terminals. When the positive electrode 22 is the "first electrode", the positive terminal 30 is an example of the "first electrode terminal". When the negative electrode 24 is the "first electrode", the negative terminal 40 is an example of the "first electrode terminal".

[0038] In case 10, the terminals (positive terminal 30 and / or negative terminal 40) are provided on the side opposite to the joint 10w between the case body 12 and the sealing plate 14. By providing the terminals (preferably the positive terminal 30 and the negative terminal 40) on the bottom wall 12a away from the joint 10w in this way, even if an external force is applied to the terminals when the energy storage device 100 is in use, for example, it is possible to suppress a large load on the joint 10w. Therefore, the joint 10w becomes less susceptible to damage, and the sealing performance and reliability of the joint 10w can be improved.

[0039] As shown in Figure 2, the terminals (positive terminal 30 and / or negative terminal 40) are insulated from the bottom wall 12a of the case body 12 by insulating members (here, a gasket 90 and an external insulating member 92). The terminals are fixed to the bottom wall 12a of the case body 12 via the gasket 90 and the external insulating member 92. The gasket 90 and the external insulating member 92 are preferably made of resin. The terminals may be attached to the bottom wall 12a together with the gasket 90 and the external insulating member 92 by an insert molding (integral molding) method. The terminals may be fixed to the bottom wall 12a together with the gasket 90 and the external insulating member 92 by crimping or the like, or they may be fixed to the bottom wall 12a via an adhesive layer (adhesive, etc.). Also, if the bottom wall 12a serves as one of the terminals, one of the terminals may be electrically connected to the bottom wall 12a directly or via another conductive member.

[0040] In the following explanation, the case where the positive electrode 22 is the "first electrode" will be used as an example, but the negative electrode 24 can also be configured similarly. In that case, the terms "positive electrode" below can be replaced with "negative electrode" as appropriate.

[0041] As shown in Figures 2 and 3, the positive electrode terminal 30 is electrically connected to the positive electrode 22 of the electrode body 20 via the positive electrode current collector 50. In this embodiment, the positive electrode terminal 30 is electrically connected to the positive electrode tab group 27 of the positive electrode 22. The positive electrode terminal 30 is preferably made of metal, and more preferably of aluminum or an aluminum alloy. In this embodiment, the positive electrode terminal 30 has a through hole 30h. In this embodiment, the through hole 30h is formed in a cylindrical shape. The positive electrode current collector 50 (specifically, the shaft portion 52 which will be described later) is inserted through the through hole 30h.

[0042] As shown in Figure 2, the negative electrode terminal 40 is electrically connected to the negative electrode 24 of the electrode body 20 via the negative electrode current collector 60. The negative electrode terminal 40 is electrically connected to the negative electrode tab group 28 of the negative electrode 24. The negative electrode terminal 40 is preferably made of metal, and more preferably of copper or a copper alloy. The negative electrode terminal 40 has the same configuration as the positive electrode terminal 30. The negative electrode terminal 40 has a through hole 40h. The through hole 40h is formed in a cylindrical shape. The negative electrode current collector 60 (specifically the shaft portion 62 described later) is inserted through the through hole 40h.

[0043] The positive electrode current collector 50 is a conductive material and constitutes a conductive path between the positive electrode 22 (specifically the positive electrode tab group 27) and the positive electrode terminal 30. By interposing the positive electrode current collector 50 between the positive electrode tab group 27 and the positive electrode terminal 30, the electrical connection can be made more stable. The positive electrode current collector 50 is preferably made of a metal with excellent conductivity, such as aluminum or an aluminum alloy. The positive electrode current collector 50 may also be made of the same metal as the positive electrode tab 22t and / or the positive electrode terminal 30. When the positive electrode 22 is the "first electrode", the positive electrode current collector 50 is an example of the "first current collector".

[0044] As shown in Figure 3, the positive electrode current collector 50 is inserted through the through hole 85h of the spacer 80 (described later), the lead hole 18 of the bottom wall 12a, and the through hole 30h of the positive electrode terminal 30, in that order from the inside of the case 10. The positive electrode current collector 50 extends from the inside (upper side of Figure 3) to the outside (lower side of Figure 3) of the case body 12. A portion of the positive electrode current collector 50 is exposed to the outside of the case 10. The positive electrode current collector 50 is attached to the electrode body 20. The positive electrode current collector 50 is integrated with the spacer 80. Figure 6 is a schematic exploded perspective view showing the combined unit including the electrode body 20, the positive electrode current collector 50, the negative electrode current collector 60, and the spacer 80.

[0045] As shown in Figures 3 and 6, the positive electrode current collector 50 has a flange portion 51 and a shaft portion 52. The flange portion 51 is provided at the upper end (the end on the electrode body 20 side) of the positive electrode current collector 50. The flange portion 51 is located inside the case 10 (more specifically, the case body 12). The flange portion 51 has a larger outer diameter than the shaft portion 52. The flange portion 51 is attached to the positive electrode tab group 27 (multiple positive electrode tabs 22t) and is electrically connected to the positive electrode 22. The flange portion 51 is joined (for example, by welding such as ultrasonic welding) to the positive electrode tab group 27 (multiple positive electrode tabs 22t).

[0046] As shown in Figure 3, the flange portion 51 here extends along the inner surface of the bottom wall 12a. In the long side direction Y, the width of the flange portion 51 is preferably approximately the same as, or wider than, the width of the positive electrode tab group 27. The flange portion 51 here has a larger outer diameter than the pull-out hole 18 of the bottom wall 12a. The flange portion 51 here has a larger outer diameter than the through hole 30h of the positive electrode terminal 30. The flange portion 51 is insulated from the bottom wall 12a of the case body 12 by an insulating member (spacer 80 here). The flange portion 51 is fitted into the stepped portion 85s of the spacer 80, which will be described later.

[0047] As shown in Figure 6, the flange portion 51 is hexagonal in this XY plan view. The corner of the flange portion 51 on one side in the short side direction X (the rear side in Figure 6) is formed in an R shape (a rounded corner). The corner of the flange portion 51 on one side in the short side direction X (the front side in Figure 6) is notched. Therefore, the flange portion 51 is asymmetrical in the short side direction X and symmetrical in the long side direction Y. A fitting recess 51r (groove, constriction) is provided on the outer circumferential wall of the flange portion 51. The fitting recess 51r is provided around the entire circumference of the flange portion 51. The fitting recess 51r is annular (for example, circular). As shown in Figure 3, the fitting projection 85c of the spacer 80, which will be described later, is fitted into the fitting recess 51r.

[0048] The shaft portion 52 is provided at the lower end (the end on the bottom wall 12a side) of the positive electrode current collector 50. The shaft portion 52 is the part that protrudes from the flange portion 51. The shaft portion 52 has a smaller outer diameter than the flange portion 51. In this case, the shaft portion 52 is smaller than the through hole 85h of the spacer 80 and is inserted through the through hole 85h. In this case, the shaft portion 52 is smaller than the lead hole 18 of the bottom wall 12a and is inserted through the lead hole 18. The shaft portion 52 is insulated from the bottom wall 12a of the case body 12 by an insulating member (gasket 90 in this case). The shaft portion 52 is smaller than the through hole 30h of the positive electrode terminal 30 and is inserted through the through hole 30h. This makes it easier to maintain a more stable electrical connection between the positive electrode terminal 30 and the positive electrode current collector 50, and improves conductivity reliability.

[0049] As shown in Figure 6, the shaft portion 52 is columnar, specifically cylindrical. The length of the shaft portion 52 in the vertical direction Z is preferably shorter than the length of the projection 12p provided on the bottom wall 12a in the vertical direction Z. This allows the projection 12p to function suitably as a positioning member for the spacer 80 and the current collector (positive electrode current collector 50 and / or negative electrode current collector 60). As described in the modified example (3) below, the shaft portion 52 may be a protrusion or the like. The shaft portion 52 is preferably circular in XY plane view. If both the shaft portion 52 and the through hole 30h of the positive electrode terminal 30 are circular in XY plane view, the insertability of the shaft portion 52 and the airtightness of the through hole 30h after the shaft portion 52 is inserted can be improved. This, in turn, can improve the reliability of the energy storage device 100.

[0050] As shown in Figure 3, the shaft portion 52 here extends from the inside to the outside of the case 10. The lower end of the shaft portion 52 is exposed to the outside of the case body 12 (the outer surface side of the bottom wall 12a). The lower end of the shaft portion 52 is contained within the through hole 30h. The lower end surface of the shaft portion 52 is substantially flush with the lower end surface (outer surface) of the positive electrode terminal 30 (allowing for manufacturing tolerances, etc.). The shaft portion 52 does not protrude from the through hole 30h in this embodiment. However, in other embodiments, the shaft portion 52 may protrude from the through hole 30h.

[0051] The positive electrode current collector 50 is joined to the positive electrode terminal 30. In this embodiment, as shown in Figure 3, the periphery of the through hole 30h of the positive electrode terminal 30 and the shaft portion 52 of the positive electrode current collector 50 inserted through the through hole 30h (particularly the tip portion on the outside side of the case body 12) are joined. The positive electrode terminal 30 and the positive electrode current collector 50 are joined on the outside of the case body 12 (on the outer surface side of the bottom wall 12a). By joining the positive electrode terminal 30 and the positive electrode current collector 50 on the outside of the case body 12, the positive electrode terminal 30 and the positive electrode current collector 50 can be joined more stably.

[0052] A joint J is formed on the outside of the case body 12. Preferably, the joint J is a welded joint formed by irradiation with an energy ray, such as laser welding. In this case, the joint J protrudes outside the through hole 30h. As shown in Figure 1, the joint J is annular (for example, circular). The joint J is continuously provided around the entire circumference at the boundary between the periphery of the through hole 30h of the positive terminal 30 and the shaft portion 52 of the positive current collector 50. This makes it easier to maintain a more stable electrical connection between the positive terminal 30 and the positive current collector 50, and improves the conductivity reliability of the joint J.

[0053] The negative electrode current collector 60 is a conductive member and constitutes a conductive path between the negative electrode 24 (specifically the negative electrode tab group 28) and the negative electrode terminal 40. The negative electrode current collector 60 is preferably made of a metal with excellent conductivity, such as copper or a copper alloy. The negative electrode current collector 60 may also be made of the same type of metal as the negative electrode tab 24t and / or the negative electrode terminal 40. Here, the negative electrode current collector 60 has the same configuration as the positive electrode current collector 50. As shown in Figure 2, the negative electrode current collector 60 has a flange portion 61 and a shaft portion 62. When the negative electrode 24 is the "first electrode", the negative electrode current collector 60 is an example of the "first current collector".

[0054] As shown in Figure 2, the spacer 80 is positioned inside the case 10 between the bottom wall 12a (specifically the inner surface, the top surface in Figure 2) and the electrode body 20 (specifically the lower surface in Figure 2). Note that in Figure 2, etc., the spacer 80, which is a key part, is drawn larger than it actually is. The spacer 80 is typically insulating and preferably made of resin. The material of the spacer 80 may be the same as the material exemplified for the electrode body holder 29. Here, the spacer 80 is a single component. However, as described in the modified example (2-2) below, the spacer 80 may be composed of multiple components. The multiple components may be assembled and integrated, or they may be positioned at spaced intervals. For example, a first spacer and a second spacer can be placed on the positive terminal 30 side and the negative terminal 40 side, respectively.

[0055] Figure 7A is a schematic plan view of the spacer 80, and Figure 7B is a schematic perspective view of the spacer. In Figure 7A, the side walls of the case body 12 (a pair of long side walls 12b and a pair of short side walls 12c) are shown together with dashed lines. Figure 7B shows the side facing the electrode body 20. As shown in Figures 6, 7A, and 7B, the spacer 80 here has a base portion 89, a through hole 81 for liquid injection, a through hole 82 for gas discharge, a positive electrode side support portion 85, and a negative electrode side support portion 86.

[0056] As shown in Figure 2, the base portion 89 extends along the bottom wall 12a of the case body 12. As shown in Figure 7A, in an XY plan view, it is preferable that the outer edge of the spacer 80 (more specifically the base portion 89) abuts against or is close to the inner surface of the side wall of the case body 12. The gap between the spacer 80 and the side wall of the case body 12 (the difference between the inner dimensions of the case body 12 and the outer dimensions of the spacer 80) is preferably 1 mm or less, more preferably 0.8 mm or less, and even more preferably 0.5 mm or less. This makes it easier for the spacer 80 to exhibit a high effectiveness as a positioning member, as described later.

[0057] As can be seen from Figure 7B, the base portion 89 has a thin-walled region A1 with a relatively thin thickness and a thick-walled region A2 with a relatively thick thickness. The thin-walled region A1 is provided in the peripheral portions of the liquid injection through-hole 81 and the gas discharge through-hole 82, the peripheral portion of the positive electrode side support portion 85, and the peripheral portion of the negative electrode side support portion 86, respectively. The thick-walled region A2 is provided in the outer edge of the base portion 89, near the pair of short side walls 12c, between the liquid injection through-hole 81 and the positive electrode side support portion 85, and between the gas discharge through-hole 82 and the negative electrode side support portion 86. The thickness of the thick-walled region A2 is preferably twice or more, and more preferably three times or more, than the thickness of the thin-walled region A1.

[0058] As shown by the dashed line in Figure 3, it is preferable that the thickened region A2 is in contact with or close to one end of the electrode body 20 (or electrode body holder 29). This allows the load to be distributed in the (step 4) insertion step or (step 5) joining step of the manufacturing method described later. It also makes it more difficult for the electrode body 20 to move within the case 10. On the other hand, it is preferable that a gap S is secured between the thinned region A1 and the electrode body 20 (or electrode body holder 29) at the periphery of the positive electrode side support portion 85 and the negative electrode side support portion 86.

[0059] The base portion 89 has a thickened region A2, and a gap S is secured around the periphery of the positive electrode support portion 85 and the negative electrode support portion 86. This allows the electrode body 20 to be supported by the bottom wall 12a via the thickened region A2, even if the bottom wall 12a of the case body 12 is positioned vertically downward during the manufacturing or use of the energy storage device 100. Therefore, damage to the conductive path, such as the positive electrode tab group 27 and / or the negative electrode tab group 28, or the joint between the positive electrode tab group 27 and the positive electrode current collector 50 and / or the joint between the negative electrode tab group 28 and the negative electrode current collector 60, due to the weight of the electrode body 20 can be effectively suppressed. However, the thickened region A2 is not essential, and the base portion 89 may be a flat plate with a substantially uniform thickness.

[0060] The through-hole 81 for liquid injection is a through-hole that penetrates the thin-walled region A1 of the base portion 89 in the vertical direction Z. As shown in Figure 2, the through-hole 81 for liquid injection is provided in the portion opposite to the electrolyte injection hole 15 (the portion that overlaps in the XY plane view). As a result, in the vertical direction Z, the electrolyte injection hole 15 is directly opposite the electrode body 20 (or electrode body holder 29). As shown in Figure 7B, reinforcing ribs 81r are provided around the through-hole 81 for liquid injection. As a result, deformation of the bottom wall 12a is suppressed even if a load is applied to the periphery of the electrolyte injection hole 15, for example, during liquid injection. The reinforcing ribs 81r are provided here around the periphery of the through-hole 81 for liquid injection and radially around the through-hole 81 for liquid injection. The reinforcing ribs 81r are connected to the thick-walled region A2. However, the through-hole 81 for electrolyte injection is not mandatory and can be omitted, for example, if the case body 12 does not have an electrolyte injection hole 15 or if the electrolyte injection hole 15 is provided on the sealing plate 14 side.

[0061] The gas discharge through-hole 82 is a through-hole that penetrates the thin-walled region A1 of the base portion 89 in the vertical direction Z. As shown in Figure 2, the gas discharge through-hole 82 is provided in the portion facing the gas discharge valve 17 (the portion that overlaps in the XY plane view). As a result, in the vertical direction Z, the gas discharge valve 17 is directly facing the electrode body 20 (or electrode body holder 29). With this configuration, the gas discharge valve 17 is more likely to open stably when the pressure inside the case 10 exceeds a predetermined value. In this case, the gas discharge through-hole 82 is set as a push-through hole. However, the gas discharge through-hole 82 is not essential and can be omitted, for example, if the gas discharge valve 17 is provided on the sealing plate 14 side.

[0062] The positive electrode side support portion 85 is provided on the electrode body 20 side surface of the base portion 89. The positive electrode side support portion 85 is provided in the thin-walled region A1. The positive electrode side support portion 85 is the part that supports the conductive path on the positive electrode 22 side. As shown in Figures 7A and 7B, the positive electrode side support portion 85 is provided with a stepped portion 85s (recess) and a through hole 85h.

[0063] The stepped portion 85s is provided on the outer edge of the through hole 85h. As can be seen from Figure 3, the positive electrode current collector 50 is positioned on the stepped portion 85s. In this case, the stepped portion 85s has the same shape as the flange portion 51 in an XY plan view. The flange portion 51 of the positive electrode current collector 50 is fitted into the stepped portion 85s. This prevents the positive electrode current collector 50 from shifting from the desired position during the insertion process (step 4) of the manufacturing method described later. Furthermore, since the positive electrode current collector 50 can be maintained in the desired position, the positive electrode current collector 50 can be stably inserted into the through hole 30h.

[0064] The through-hole 85h is provided within the stepped portion 85s. The positive electrode current collector member 50 (specifically, the columnar shaft portion 52) is inserted through the through-hole 85h. In this embodiment, the outer circumference of the through-hole 85h is closed. However, the outer circumference of the through-hole 85h does not necessarily have to be closed; for example, as described in the modified example (2-1) described later, it may have an opening. As shown in Figure 3, a fitting projection 85c is provided on the inner wall surface of the through-hole 85h. The fitting projection 85c of the through-hole 85h is fitted into the fitting recess 51r of the positive electrode current collector member 50. In this embodiment, the fitting projection 85c is provided on the spacer 80 and the fitting recess 51r is provided on the positive electrode current collector member 50, but in other embodiments, the opposite may be true: the fitting recess may be provided on the spacer 80 side and the fitting projection on the positive electrode current collector member 50 side.

[0065] The negative electrode side support portion 86 is provided on the electrode body 20 side surface of the base portion 89. The negative electrode side support portion 86 is provided in the thin-walled region A1. The negative electrode side support portion 86 is the part that supports the conductive path on the negative electrode 24 side. The negative electrode side support portion 86 has the same configuration as the positive electrode side support portion 85. The negative electrode side support portion 86 is provided symmetrically with respect to the positive electrode side support portion 85. As shown in Figures 7A and 7B, the negative electrode side support portion 86 is provided with a stepped portion 86s (recess) and a through hole 86h.

[0066] The stepped portion 86s is provided on the outer edge of the through hole 86h. As can be seen from Figure 2, the negative electrode current collector 60 is positioned in the stepped portion 86s. Here, the flange portion 61 of the negative electrode current collector 60 is fitted into the stepped portion 86s. The through hole 86h is provided inside the stepped portion 86s. The negative electrode current collector 60 (specifically, the columnar shaft portion 62) is inserted through the through hole 86h. Although not shown in the figure, a fitting projection is also provided on the inner wall surface of the through hole 86h, similar to the through hole 85h on the positive electrode side. The fitting projection of the through hole 86h is fitted into the fitting recess of the negative electrode current collector 60.

[0067] In this embodiment, the following (a) to (c): (a) The spacer 80 has through holes 85h and 86h, the columnar shaft portion 52 of the positive electrode current collector member 50 (part of the first current collector member) is inserted through hole 85h, and the columnar shaft portion 62 of the negative electrode current collector member 60 (part of the first current collector member) is inserted through hole 86h; (b) The spacer 80 has stepped portions 85s and 86s (recesses), the flange portion 51 of the positive electrode current collector member 50 (part of the first current collector member) is fitted into the stepped portion 85s, and the flange portion 61 of the negative electrode current collector member 60 (part of the first current collector member) is fitted into the stepped portion 86s; (c) The spacer 80 has through holes 85h and 86h, and fitting protrusions 85c are provided on the inner walls of the through holes 85h and 86h, the positive electrode current collector member 50 has a fitting recess 51r, the negative electrode current collector member 60 has a fitting recess, and the fitting recess 51r and the fitting protrusion 85c are fitted together; In this configuration, the spacer 80 is integrated (more specifically, mechanically connected) with the current collector (positive electrode current collector 50 and / or negative electrode current collector 60). In other words, the spacer 80 is assembled to the current collector. The spacer 80 is also integrated (connected) with the electrode body 20 via the current collector.

[0068] Because the spacer 80 and the current collector (positive electrode current collector 50 and / or negative electrode current collector 60) are integrated, the current collector and electrode body 20 can be guided to the desired position in the insertion step (step 4) of the manufacturing method described later. In other words, the spacer 80 can function as a positioning member for the current collector and electrode body 20. Consequently, in the joining step (step 5) of the manufacturing method described later, the current collector can be brought into stable contact with the terminals (positive electrode terminal 30 and / or negative electrode terminal 40), making joining easier.

[0069] In this embodiment, the spacer 80 and the current collector are integrated by the configurations (a) to (c) described above, but the method of integrating the spacer 80 and the current collector is not limited to the above. For example, fixing claws may be provided on the upper or lower surface of the spacer 80, and the current collector may be fixed by hooking a part of the current collector (for example, flanges 51, 61) with the claws. Alternatively, the spacer 80 and the electrode body 20 (or electrode body holder 29) may be fixed together with tape or the like, thereby integrating them without the current collector. Furthermore, it is not necessary to have all of the configurations (a) to (c) described above; it is sufficient to have at least one (preferably more, more preferably all) configurations. In some embodiments, it is preferable that the spacer 80 and the current collector are connected in such a way that when the spacer 80 is pressed against the bottom wall 12a side via the electrode body 20, the spacer 80 can easily press the current collector against the terminal. For example, the form disclosed in Figure 3, the form with a claw for hooking and fixing, or the first modified form described later are preferred.

[0070] Furthermore, as shown in Figures 6, 7A, and 7B, the spacer 80 of this embodiment also has a hole 87. As shown in Figure 4, the hole 87 is provided on the bottom wall 12a side of the base portion 89. The hole 87 is provided at a position corresponding to the projection 12p provided on the inner surface of the bottom wall 12a. The hole 87 is a through hole that penetrates the thickened region A2 of the base portion 89 in the vertical direction Z. The projection 12p is inserted into the hole 87. This positions the spacer 80 with respect to the bottom wall 12a of the case body 12. Consequently, the current collector (positive electrode current collector 50 and / or negative electrode current collector 60) integrated with the spacer 80 is positioned. From the viewpoint of improving the insertability of the projection 12p, it is preferable that the diameter of the hole 87 gradually increases toward the bottom wall 12a side.

[0071] In this specification, the term "hole" includes not only through holes (parts that penetrate to the other side) as in this embodiment, but also recesses (recesses) provided on the inner surface of the bottom wall 12a side of the base 89, to the extent that they can accommodate at least a part of the projection 12p. In this embodiment, the projection 12p (convex part) is provided on the bottom wall 12a and the hole 87 is provided on the spacer 80, but in other embodiments, the opposite may be true: the projection may be provided on the spacer 80 side and the hole on the bottom wall 12a side.

[0072] [Manufacturing method for energy storage devices] The energy storage device 100 of this embodiment can be manufactured by a method including, for example, the following steps: (Step 1A) Case preparation step; (Step 1B) Electrode preparation step; (Step 2) Connection step; (Step 3) Assembly step; (Step 4) Insertion step; (Step 5) Bonding step; (Step 6) Sealing step. However, the order of (Step 1A) Case preparation step and (Step 1B) Electrode preparation step is not particularly limited and may be reversed or substantially simultaneous. Also, the order of (Step 1A) Case preparation step and (Step 2) Connection step is not particularly limited and may be reversed or substantially simultaneous. Also, the order of (Step 2) Connection step and (Step 3) Assembly step is not particularly limited and may be reversed or substantially simultaneous. Furthermore, the manufacturing method disclosed herein may include other steps at any stage. For example, after (Step 6) Sealing step, a step of pouring electrolyte into the case 10 may be included.

[0073] (Step 1A) In the case preparation step, the case body 12 and the sealing plate 14 are prepared before the insertion step. Specifically, a bottomed cylindrical case body 12 having a bottom wall 12a, side walls 12b, 12c and an opening 12h, and a sealing plate 14 that seals the opening 12h are prepared. The case body 12 and the sealing plate 14 may be purchased from a supplier or the like, or they can be manufactured in-house. In some embodiments, the case body 12 may have terminals (positive terminal 30 and / or negative terminal 40) attached to the bottom wall 12a in advance. Preferably, the terminals are attached to the bottom wall 12a in an insulated state from the bottom wall 12a via insulating members (e.g., gasket 90 and external insulating member 92).

[0074] The method of attaching the terminals is not particularly limited. The terminals may be pre-attached to the bottom wall 12a by insert molding (integral molding), for example, together with the gasket 90 and the external insulating member 92. That is, the case body 12 may be prepared as an integrally molded product integrated with the gasket 90, the external insulating member 92, and the terminals (positive terminal 30 and / or negative terminal 40). Alternatively, the terminals may be attached to the bottom wall 12a by crimping (riveting), for example, together with the gasket 90 and the external insulating member 92, or they may be attached to the bottom wall 12a via an adhesive layer (adhesive, etc.). Furthermore, the terminals do not necessarily need to be attached to the bottom wall 12a beforehand; they can also be attached to the bottom wall 12a by insertion or joining processes, for example, as described later.

[0075] (Step 1B) In the electrode preparation step, the electrode body 20 is prepared. The electrode body 20 may be a purchased item supplied by a supplier, etc., or it may be manufactured in-house. In one example, first, a strip-shaped positive electrode 22 and a strip-shaped negative electrode 24 are stacked via a strip-shaped separator 26, and then wound in the longitudinal direction LD with the winding axis WL as the center to form a cylindrical shape. At this time, multiple positive electrode tabs 22t and multiple negative electrode tabs 24t are adjusted so that they protrude from the same end and are stacked at different positions. Next, the cylindrically wound electrode body (cylindrical body) is pressed into a flat shape, for example, to produce a flat electrode body 20. Then, multiple positive electrode tabs 22t are bundled together and integrated as a positive electrode tab group 27. Similarly, multiple negative electrode tabs 24t are bundled together and integrated as a negative electrode tab group 28.

[0076] (Step 2) In the connection step, the first current collector (positive electrode current collector 50 or negative electrode current collector 60) is electrically connected to the first electrode (positive electrode 22 or negative electrode 24) of the electrode body 20. That is, a conductive path is formed between the first electrode and the first current collector. In this embodiment, the flange portion 51 of the positive electrode current collector 50 is joined to the positive electrode tab group 27 of the positive electrode 22, thereby electrically connecting the positive electrode current collector 50 to the positive electrode 22. Similarly, the flange portion 61 of the negative electrode current collector 60 is joined to the negative electrode tab group 28 of the electrode body 20, thereby electrically connecting the negative electrode current collector 60 to the negative electrode 24. The joining method may be the same as in the conventional method and is not particularly limited. In some embodiments, it is preferable to weld the joining by irradiation with an energy ray, such as ultrasonic welding, resistance welding, or laser welding. As a result, the electrode body 20 is integrated (mechanically connected) with the current collector. The electrode body 20 is then covered with an electrode body holder 29 (such as a resin sheet).

[0077] In this embodiment, when two electrode bodies 20 are housed inside a single case 10, the positive electrode tab group 27 of the first electrode body 20 and the positive electrode tab group 27 of the second electrode body 20 may be joined to a single positive electrode current collector member 50, and the negative electrode tab group 28 of the first electrode body 20 and the negative electrode tab group 28 of the second electrode body 20 may be joined to a single negative electrode current collector member 60. This allows the two electrode bodies 20 to be combined into a single composite unit.

[0078] (Step 3) In the assembly process, before the insertion process (before inserting the electrode body 20 into the case body 12), the spacer 80 is placed on one end of the electrode body 20 to which the first current collector (positive electrode current collector 50 or negative electrode current collector 60) is attached (the end on the side where the first current collector is provided). The first current collector is then assembled to the spacer 80, so that the first current collector and the spacer 80 are integrated. This makes it easier to guide the first current collector and the electrode body 20 to the desired position in the insertion process described later. In other words, the spacer 80 can function as a positioning member for the first current collector and the electrode body 20. Furthermore, in the joining process described later, the first current collector can be stably brought into contact with the first electrode terminal (positive electrode terminal 30 or negative electrode terminal 40) and stably joined.

[0079] As described above, the spacer 80 of this embodiment has through holes 85h and 86h (see Figure 7A). Therefore, for example, when the spacer 80 is placed over the first current collector from above, a part of the first current collector (positive electrode current collector 50 or negative electrode current collector 60) (for example, the columnar shaft portion 52, 62) is inserted through the through holes 85h and 86h. This integrates the first current collector and the spacer 80. The columnar shaft portions 52, 62 of the first current collector protrude from the through holes 85h and 86h of the spacer 80. With this configuration, the positioning of the first current collector can be performed more effectively in the insertion process described later. In addition, in the joining process, the first current collector and the first electrode terminal can be joined together more stably by bringing them into contact.

[0080] Furthermore, the spacer 80 in this embodiment has stepped portions 85s and 86s (recesses, see Figure 7A). Therefore, when the spacer 80 is placed at one end of the electrode body 20, a part of the first current collector (positive electrode current collector 50 or negative electrode current collector 60) (for example, flange portions 51 and 61) is fitted into the stepped portions 85s and 86s. The surface of the first current collector on the electrode body 20 side is supported by the stepped portions 85s and 86s (support portions) of the spacer 80. Here, the first electrode tab group (positive electrode tab group 27 or negative electrode tab group 28) is further inserted through the through holes 85h and 86h of the spacer 80. Also, the thickened region A2 of the spacer 80 is supported at one end of the electrode body 20. As a result, the first current collector and the spacer 80 are integrated. With this configuration, the positioning of the first current collector can be performed more effectively in the insertion process described later. Furthermore, during the joining process, the first current collector and the first electrode terminal are brought into more stable contact, making joining easier.

[0081] Furthermore, the spacer 80 in this embodiment has through holes 85h and 86h (see Figure 7A), and fitting protrusions 85c (see Figure 3) are provided on the inner wall surfaces of the through holes 85h and 86h. In addition, the first current collector (positive electrode current collector 50 or negative electrode current collector 60) is provided with a fitting recess 51r at a position opposite to the fitting protrusion 85c. Therefore, when the spacer 80 is placed at one end of the electrode body 20, the fitting protrusion 85c is fitted into the fitting recess 51r of the first current collector. As a result, the current collector is firmly fixed to the spacer 80, and the unity between the spacer 80 and the current collector is enhanced.

[0082] As described above, in this process, the first current collector and the spacer 80 are integrated, and a composite object including the electrode body 20, the first current collector and the spacer 80 is manufactured as shown in Figure 7. In this embodiment, in (step 2) the connection step, the first current collector is first electrically connected to the first electrode of the electrode body 20, and in (step 3) the assembly step, the spacer 80 is integrated to the first current collector. However, as stated above, the order of these steps is not particularly limited. For example, in the opposite case to this embodiment, the spacer 80 may be attached to the first current collector first, and then the first current collector may be electrically connected to the first electrode of the electrode body 20.

[0083] (Step 4) In the insertion process, after the case preparation process and assembly process, the electrode body 20, which is integrated with the spacer 80, is inserted into the case body 12 from one end of the electrode body 20 (the spacer 80 side). Specifically, the electrode body 20 is inserted from the opening 12h of the case body 12 so that the side to which the current collectors (positive electrode current collector 50 and / or negative electrode current collector 60) are attached faces the bottom wall 12a. Figure 8A is an explanatory diagram of the insertion process, and Figure 8B is a magnified view of the vicinity of the positive electrode terminal 30, which is a key part. Note that in Figures 8A and 8B, the bottom wall 12a of the case body 12 is in an inverted position facing vertically upward, taking into consideration the workability in the joining process described later. Also, Figure 8B shows a cross-section of the bottom wall 12a passing through the pull-out hole 18 and the projection 12p.

[0084] As described above, the spacer 80 of this embodiment is configured such that its outer edge abuts against or is close to the inner surface of the side walls (a pair of long side walls 12b and a pair of short side walls 12c) of the case body 12. Therefore, as shown in Figure 8A, the spacer 80 inserted into the case body 12 moves along the side walls 12b and 12c of the case body 12 toward the bottom wall 12a. Thus, it is easier to maintain the electrode body 20 in a horizontal position, and it is possible to prevent the electrode body 20 from being housed in the case body 12 in a tilted position or from getting caught on the side walls during movement. In other words, the spacer 80 of this embodiment makes it easier to guide the electrode body 20 to the desired position.

[0085] Furthermore, in this embodiment, since the current collectors (positive electrode current collector 50 and / or negative electrode current collector 60) and the spacer 80 are integrated, as the spacer 80 moves along the side walls 12b and 12c of the case body 12 toward the bottom wall 12a, the current collectors also move toward the bottom wall 12a. Then, as can be seen from Figures 8A and 8B, at least a part of the current collectors is inserted into the through holes 30h and 40h of the terminals (positive electrode terminal 30 and / or negative electrode terminal 40). Specifically, the columnar shaft portion 52 of the positive electrode current collector 50 is inserted through the through hole 30h of the positive electrode terminal 30, and the columnar shaft portion 62 of the negative electrode current collector 60 is inserted through the through hole 40h of the negative electrode terminal 40. As a result, the current collectors are stably inserted into the through holes of the terminals provided in the bottom wall 12a. In other words, the spacer 80 in this embodiment can function as a positioning member that guides the current collectors to a desired joining position.

[0086] Furthermore, as shown in Figure 8B, in this embodiment, a projection 12p (protrusion) is provided on the inner surface side of the bottom wall 12a, and a hole 87 is provided in the spacer 80. Therefore, as indicated by the arrow in Figure 8B, when the spacer 80 approaches the bottom wall 12a, the projection 12p of the bottom wall 12a is inserted into the hole 87 of the spacer 80. This allows the spacer 80 to be positioned relative to the case body 12 (more specifically, the bottom wall 12a). In particular, in this embodiment, since the length of the projection 12p in the vertical direction Z is longer than the length of the shaft portion 52 in the vertical direction Z, the projection 12p of the bottom wall 12a is inserted into the hole 87 of the spacer 80 before at least a part of the current collector is inserted into the through holes 30h and 40h of the terminals. This allows positional tolerances to be absorbed, and the spacer 80 can be positioned more effectively relative to the case body 12. In other words, the current collector integrated with the spacer 80 can be positioned with high precision relative to the through holes 30h and 40h provided in the bottom wall 12a.

[0087] In this embodiment, as shown in Figure 8A, the process is performed in an inverted position where the bottom wall 12a of the case body 12 faces upward in the vertical direction. However, if, for example, the electrode body 20 is heavy, the process may be performed in a position where the side walls (a pair of long side walls 12b or a pair of short side walls 12c) are positioned vertically above and below, and the short or long side of the bottom wall 12a extends vertically.

[0088] (Step 5) In the joining process, after the insertion process, the first current collector (positive electrode current collector 50 or negative electrode current collector 60) and the first electrode terminal (positive electrode terminal 30 or negative electrode terminal 40) are joined. Figure 9 is an explanatory diagram of the joining process. Note that in Figure 9, as in Figure 8A, the bottom wall 12a is in an inverted position facing upward in the vertical direction.

[0089] In this embodiment, prior to the joining process, as shown in Figure 3, the fitting recess 51r of the positive electrode current collector member 50 and the fitting projection 85c of the spacer 80 are fitted together. Therefore, while the bottom wall 12a is inverted with the bottom wall 12a facing upward in the vertical direction, when the electrode body 20 is pressed from the opening 12h side toward the bottom wall 12a side and a load P is applied, as shown by the arrow in Figure 9, a load P1 is applied to the spacer 80 via the portion in contact with the electrode body 20 (thickened region A2, the dashed line in Figure 9). As a result, the first current collector member is pressed against the first electrode terminal via the spacer 80. Thus, the first current collector member can be suitably pressed against the first electrode terminal. Specifically, the state in which the shaft portions 52 and 62 of the first current collector member are inserted into the through holes 30h and 40h of the first electrode terminal can be suitably maintained. Preferably, the periphery of the through holes 30h and 40h of the first electrode terminal and the end faces of the shaft portions 52 and 62 of the first current collector member can be kept substantially flush.

[0090] The electrode body 20 may be pressed by directly applying a load to its lower vertical end face (the end face opposite to the side on which the first current collector is provided), or it may be pressed via another member (for example, an electrode body holder 29, another spacer, jig, sealing plate 14, etc.). In this embodiment, the electrode body 20 is pressed via the sealing plate 14. This makes it easier to press the electrode body 20 uniformly.

[0091] Then, with the first current collector (positive electrode current collector 50 or negative electrode current collector 60) pressed against the first electrode terminal (positive electrode terminal 30 or negative electrode terminal 40), the points where the first current collector and the first electrode terminal come into contact are joined. At this time, as shown by the arrows in Figure 9, it is more preferable to press the first electrode terminal against the bottom wall 12a side of the case body 12 using a jig or the like. In this embodiment, the portions of the first current collector inserted into the through holes 30h and 40h (the tips of the shaft portions 52 and 62) are joined to the first electrode terminal. This allows the first current collector and the first electrode terminal to come into contact accurately and to be joined more stably.

[0092] The joining method is not particularly limited. In some embodiments, as shown in Figure 9, it is preferable to weld the case body 12 by irradiating it with an energy ray such as a laser LB from the outside (the outer surface side of the bottom wall 12a). By joining from the outside of the case body 12, the joint can be visually inspected, making it easier to join the current collector and the terminal more stably. In this embodiment, an annular (e.g., circular) joint J is formed along the through holes 30h and 40h.

[0093] (Step 6) In the sealing process, the sealing plate 14 is fitted into the opening 12h of the case body 12, and the periphery of the opening 12h of the case body 12 and the sealing plate 14 are joined. This forms a joint 10w and seals the case 10. The joining method may be the same as in the conventional method and is not particularly limited. In some embodiments, it is preferable to weld the joint between the case body 12 and the sealing plate 14 by irradiating the fitting portion of the case body 12 and the sealing plate 14 along the periphery of the opening 12h with an energy ray such as a laser. The energy storage device 100 can be manufactured in this manner.

[0094] [Uses of energy storage devices] The energy storage device 100 can be used for various purposes, but it is particularly suitable for applications where a load may be applied to the terminals (positive terminal 30 and / or negative terminal 40) during use, such as a power source (driving power supply) for a motor mounted on a mobile vehicle (typically a passenger car, truck, or other vehicle). The type of vehicle is not particularly limited, but examples include plug-in hybrid electric vehicles (PHEVs), hybrid electric vehicles (HEVs), and battery electric vehicles (BEVs).

[0095] Although several embodiments of the present invention have been described above, these embodiments are merely examples. The present invention can be implemented in various other forms. The present invention can be implemented based on the contents disclosed herein and common technical knowledge in the art. The technologies described in the claims include various modifications and changes to the embodiments illustrated above. For example, it is possible to replace parts of the above embodiments with other variations, and it is also possible to add other variations to the above embodiments. Furthermore, if a technical feature is not described as essential, it may be deleted as appropriate.

[0096] (1) Current collector and electrode tab: (1-1) For example, in the embodiment described above, the positive electrode current collector 22c of the positive electrode 22 was a metal foil, specifically an aluminum foil. Also, the negative electrode current collector 24c of the negative electrode 24 was a metal foil, specifically a copper foil. However, it is not limited to this. In a modified example, the current collector (positive electrode current collector 22c and / or negative electrode current collector 24c, preferably both) is preferably configured to include an insulating core (e.g., a resin layer) and a pair of metal layers formed on a pair of surfaces (both sides) of the core. Although not particularly limited, the total thickness of the current collector is preferably 20 μm or less, and more preferably 10 μm or less.

[0097] The core is preferably made of a resin such as polyethylene terephthalate (PET), nylon, polypropylene (PP), or polyethylene (PE). The thickness of the core is preferably 50% or more of the total thickness of the current collector, which is 100%. This reduces the weight of the electrode body 20, and effectively suppresses damage to the electrode tabs and electrode body 20 when the electrode tabs (positive electrode tab 22t and / or negative electrode tab 24t) are positioned vertically downwards when the energy storage device 100 is in use. Furthermore, the metal layer is preferably made of materials such as aluminum, aluminum alloy, copper, copper alloy, nickel, nickel alloy, iron, or iron alloy.

[0098] (1-2) In addition, for example, in the embodiment described above, the electrode tabs (positive electrode tab 22t and / or negative electrode tab 24t) were regions in which the active material layer (positive electrode active material layer 22a and / or negative electrode active material layer 24a) of the current collector (positive electrode current collector 22c and / or negative electrode current collector 24c) was not formed. However, it is not limited to this. The electrode tabs may be separate components from the current collector. For example, if the current collector has a configuration including a core and a pair of metal layers as described above, a conductive member made of a metal foil or metal plate thicker than the metal layers may be attached to the metal layer portion, and the conductive member may be connected to the current collector (positive electrode current collector 50 and / or negative electrode current collector 60) as an electrode tab.

[0099] (2) Spacer: (2-1) Figure 10 is an explanatory diagram of the assembly process according to the first modified example. The spacer 180 shown in Figure 10 has a positive electrode side support portion 185 and a negative electrode side support portion 186. The positive electrode side support portion 185 has a through hole 185h, and an opening 185n is provided on one side of the through hole 185h in the short side direction X. The negative electrode side support portion 186 has a through hole 186h, and an opening 186n is provided on one side of the through hole 186h in the short side direction X. The openings 185n and 186n are larger than the columnar shaft portions 52 and 62 of the first current collector member (positive electrode current collector member 50 or negative electrode current collector member 60). In this case, (Step 3) assembly process, as shown by the arrows in Figure 10, the spacer 80 is slid (inserted) from the side of the first current collector, so that the first current collector is inserted through the openings 185n and 186n into the through holes 85h and 86h, and the spacer 180 can be assembled to the first current collector.

[0100] In some embodiments, as in this modified example, it is preferable that the positive electrode side support portion 185 is positioned between the positive electrode current collector member 50 and the electrode body 20. This allows the positive electrode side support portion 185 to support the electrode body 20-side surface of the positive electrode current collector member 50. It is also preferable that the negative electrode side support portion 186 is positioned between the negative electrode current collector member 60 and the electrode body 20. This allows the negative electrode side support portion 186 to support the electrode body 20-side surface of the negative electrode current collector member 60. When the positive electrode 22 is the "first electrode," the positive electrode side support portion 185 is an example of a "support portion that supports the electrode body-side surface of the first current collector member." When the negative electrode 24 is the "first electrode," the negative electrode side support portion 186 is an example of a "support portion that supports the electrode body-side surface of the first current collector member."

[0101] In this modified example, in step 5, during the joining process, it is preferable to join the positive electrode current collector 50 to the positive electrode terminal 30 while the positive electrode side support portion 185 is pressing the electrode body 20-side surface of the positive electrode current collector 50 toward the positive electrode terminal 30. It is also preferable to join the negative electrode current collector 60 to the negative electrode terminal 40 while the negative electrode side support portion 186 is pressing the electrode body 20-side surface of the negative electrode current collector 60 toward the negative electrode terminal 40.

[0102] (2-2) Also, for example, in the embodiment of Figure 7A described above, the spacer 80 was a single component. However, it is not limited to this. Figure 11 is an explanatory diagram of the assembly process according to the second modified example. As shown in Figure 11, the spacer 280 has a first portion 281 and a second portion 282 that are divided in the short side direction X. In this case, in the (step 3) assembly process, the spacer 280 may be assembled to the first current collector member by sandwiching the first current collector member from both sides in the short side direction X with the first portion 281 and the second portion 282 of the spacer 280, as shown by the arrows in Figure 11. In the second modified example, similar to the first modified example, the positive electrode side support portion 285 supports the electrode body 20 side surface of the positive electrode current collector member 50, and the negative electrode side support portion 286 supports the electrode body 20 side surface of the negative electrode current collector member 60.

[0103] In this modified example, the first part 281 has a protrusion 281c and a recess 281r on the surface facing the second part 282. The protrusion 281c and recess 281r are provided at both ends in the long side direction Y. Although not shown in the illustration, the second part 282 has a recess at a position facing the protrusion 281c of the first part 281 and a protrusion at a position facing the recess 281r of the first part 281. Therefore, in the assembly step (step 3), the protrusion 281c of the first part 281 is fitted into the recess of the second part 282, and the protrusion of the second part 282 is fitted into the recess 281r of the first part 281. As a result, the first part 281 and the second part 282 are integrated.

[0104] (3) Terminal shape: For example, in the embodiment shown in Figure 2 above, the terminals (positive terminal 30 and / or negative terminal 40) had through holes 30h and 40h. However, the invention is not limited to this. Figure 12 is a partially enlarged view of the vicinity of the positive terminal 130 in a modified example. As shown in Figure 12, the positive terminal 130 has a thin-walled portion 130t. The thin-walled portion 130t is located opposite the shaft portion 152 of the positive current collector member 150. In this case, in the (step 5) joining process, the positive terminal 130 and the positive current collector member 150 are joined (e.g., by welding) so as to penetrate the thin-walled portion 130t of the positive terminal 130, and a joint portion Jt is formed.

[0105] (4) Terminal installation: For example, in the embodiment described above, in (Step 1A) the case preparation step, terminals (positive terminal 30 and / or negative terminal 40) were pre-attached to the bottom wall 12a of the case body 12. However, the invention is not limited to this. The terminals can also be attached to the bottom wall 12a in (Step 5) the joining step, for example. In one example, first, in (Step 4) the insertion step, the portions of the pull-out holes 18 and 19 of the bottom wall 12a are sandwiched between the first terminal (positive terminal 30 or negative terminal 40) and the first current collector member (positive current collector member 50 or negative current collector member 60) from the inside and outside of the case body 12, and at least a part of the current collector member is inserted into the first through hole (through hole 30h or through hole 40h) of the terminal. Then, in (Step 5) the joining step, the first terminal is fixed from the outside with a jig, and the first terminal and the first current collector member are joined (for example, by welding). This allows the first terminal to be attached to the bottom wall 12a (via an insulating member, if necessary) almost simultaneously with the formation of the joint J.

[0106] As described above, specific embodiments of the technology disclosed herein include those described in the following sections. Item 1: A method for manufacturing an energy storage device, comprising an electrode body including a first electrode and a second electrode, a case for housing the electrode body, and a first electrode terminal electrically connected to the first electrode via a first current collector, wherein the case comprises a bottomed cylindrical case body having a bottom wall, a side wall provided on the outer peripheral edge of the bottom wall, and an opening facing the bottom wall, and a sealing plate for sealing the opening of the case body, wherein the first electrode terminal is attached to the bottom wall of the case body, and further comprises a spacer disposed between the bottom wall and the electrode body, the assembly step of arranging the spacer at one end of the electrode body to which the first current collector is attached and integrating the first current collector with the spacer, the insertion step of inserting the electrode body, which is integrated with the spacer, into the case body from the one end, and the joining step of joining the first current collector and the first electrode terminal after the insertion step. Item 2: The manufacturing method according to Item 1, wherein in the joining step, the electrode body is pressed against the bottom wall side, thereby joining the first current collector member and the first electrode terminal with the spacer in place. Item 3: The manufacturing method according to Item 2, wherein the spacer has a support portion that supports the electrode body side surface of the first current collector member. Item 4: The manufacturing method according to any one of items 1 to 3, wherein the spacer has a through hole, and in the assembly step, a part of the first current collector passes through the through hole of the spacer. Item 5: The manufacturing method according to any one of items 1 to 4, wherein the spacer has a recess, and in the assembly step, a part of the first current collector is fitted into the recess of the spacer. Item 6: The manufacturing method according to any one of items 1 to 5, wherein the spacer has a through hole, the inner wall of the through hole is provided with either a fitting recess or a fitting projection, the outer peripheral wall of the first current collector is provided with the other of the fitting recess or fitting projection, and in the assembly step, the fitting recess and the fitting projection are fitted together. Item 7: The manufacturing method according to any one of items 1 to 6, wherein the bottom wall of the case body is provided with either a projection or a hole, the bottom wall side surface of the spacer is provided with the other of the projection or hole, and in the insertion step, the projection is inserted into the hole. Item 8: An energy storage device comprising an electrode body including a first electrode and a second electrode, a case housing the electrode body, and a first electrode terminal electrically connected to the first electrode via a first current collector, wherein the case comprises a bottomed cylindrical case body having a bottom wall, a side wall provided on the outer peripheral edge of the bottom wall, and an opening facing the bottom wall, and a sealing plate that seals the opening of the case body, the first electrode terminal being attached to the bottom wall of the case body, and further comprising a spacer positioned between the bottom wall and the electrode body and integrated with the first current collector. Item 9: The energy storage device according to Item 8, wherein the spacer has a through hole, and a portion of the first current collector passes through the through hole. Item 10: The energy storage device according to item 8 or 9, wherein the spacer has a recess, and a portion of the first current collector is fitted into the recess of the spacer. Item 11: The energy storage device according to any one of items 8 to 10, wherein the spacer has a through hole, the inner wall of the through hole is provided with either a fitting recess or a fitting projection, and the outer peripheral wall of the first current collector is provided with the other of the fitting recess or fitting projection, and the fitting recess and the fitting projection are fitted together. Item 12: The energy storage device according to any one of items 8 to 11, wherein the spacer has a support portion that supports the electrode body side surface of the first current collector member. Item 13: The energy storage device according to any one of items 8 to 12, wherein the bottom wall of the case body is provided with either a projection or a hole, and the bottom wall side surface of the spacer is provided with the other of the projection or hole, and the projection is inserted into the hole. [Explanation of Symbols]

[0107] 10 cases 12 Case body 12a Bottom wall 12p protrusion 14 Sealing plate 20 Electrode body 22 Positive electrode (1st electrode / 2nd electrode) 24 Negative electrode (1st electrode / 2nd electrode) 30 Positive terminal (first electrode terminal) 40 Negative terminal 50 Positive electrode current collector (first current collector) 51 Guard section 52 Shaft section 51r Fitting recess 52 Shaft section 60 Negative electrode current collector 80, 180, 280 spacers 85, 185 Positive side support part 86, 186 Negative electrode side support part 85h, 86h, 185h, 186h through hole 85s, 86s Stepped section (recess) 85c Mating protrusion 87 Hole 100 Energy storage devices

Claims

1. An electrode body including a first electrode and a second electrode, A case for housing the electrode body, A first electrode terminal electrically connected to the first electrode via a first current collector, Equipped with, The aforementioned case is, A bottomed cylindrical case body having a bottom wall, a side wall provided on the outer edge of the bottom wall, and an opening facing the bottom wall, A sealing plate that seals the opening of the case body, A method for manufacturing an energy storage device, comprising: The first electrode terminal is attached to the bottom wall of the case body, The system further comprises a spacer disposed between the bottom wall and the electrode body, The assembly process involves placing the spacer at one end of the electrode body to which the first current collector is attached, and integrating the first current collector with the spacer. Insertion step of inserting the electrode body, which is integrated with the spacer, into the case body from one end, After the insertion step, a joining step is performed to join the first current collector and the first electrode terminal, A method for manufacturing an energy storage device, including the method described above.

2. In the joining process, the electrode body is pressed against the bottom wall side, thereby pressing the first current collector member against the first electrode terminal via the spacer, and the first current collector member and the first electrode terminal are joined together. The manufacturing method according to claim 1.

3. The spacer has a support portion that supports the electrode body side surface of the first current collector member. The manufacturing method according to claim 2.

4. The aforementioned spacer has a through hole, In the assembly process, a portion of the first current collector passes through the through hole of the spacer. The manufacturing method according to any one of claims 1 to 3.

5. The previous spacer has a recess, In the assembly process, a part of the first current collector is fitted into the recess of the spacer. The manufacturing method according to any one of claims 1 to 3.

6. The aforementioned spacer has a through hole, The inner wall of the through hole is provided with either a fitting recess or a fitting projection. The outer peripheral wall of the first current collector member is provided with the other of the fitting recess and the fitting projection. In the assembly process described above, the fitting recess and the fitting projection are fitted together. The manufacturing method according to any one of claims 1 to 3.

7. The bottom wall of the case body is provided with either a projection or a hole. The bottom wall side surface of the spacer is provided with the other of the projection and the hole. In the insertion step, the projection is inserted into the hole. The manufacturing method according to any one of claims 1 to 3.

8. An electrode body including a first electrode and a second electrode, A case for housing the electrode body, A first electrode terminal electrically connected to the first electrode via a first current collector, Equipped with, The aforementioned case is, A bottomed cylindrical case body having a bottom wall, a side wall provided on the outer edge of the bottom wall, and an opening facing the bottom wall, A sealing plate that seals the opening of the case body, Equipped with, The first electrode terminal is attached to the bottom wall of the case body, The system further comprises a spacer disposed between the bottom wall and the electrode body, which is integrated with the first current collector. Energy storage device.

9. The aforementioned spacer has a through hole, A portion of the first current collector member penetrates the through hole. The energy storage device according to claim 8.

10. The previous spacer has a recess, A portion of the first current collector is fitted into the recess of the spacer. The energy storage device according to claim 8 or 9.

11. The aforementioned spacer has a through hole, The inner wall of the through hole is provided with either a fitting recess or a fitting projection. The outer peripheral wall of the first current collector member is provided with the other of the fitting recess and the fitting projection. The fitting recess and the fitting protrusion are fitted together. The energy storage device according to claim 8.

12. The spacer has a support portion that supports the electrode body side surface of the first current collector member. The energy storage device according to claim 8 or 9.

13. The bottom wall of the case body is provided with either a projection or a hole. The bottom wall side surface of the spacer is provided with the other of the projection and the hole. The aforementioned projection is inserted into the hole. The energy storage device according to claim 8 or 9.

Images