Energy storage device and method for manufacturing the same

Abstract

To provide an energy storage device with high conductivity. [Solution] The energy storage device disclosed herein comprises an electrode body 20 including a first electrode and a second electrode, a case housing the electrode body 20, and a first electrode terminal 30 electrically connected to the first electrode via a first conductive member 50. The case comprises a bottomed cylindrical case body having a bottom wall 12a and an opening facing the bottom wall 12a, and a sealing plate that seals the opening of the case body. The first electrode terminal 30 is attached to the bottom wall 12a and has a through hole 30h. The first conductive member 50 is inserted into the through hole 30h and joined to the first electrode terminal 30.

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 housing 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 conductive 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 conductive 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 conductive 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 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 conductive member. 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. The first electrode terminal is attached to the bottom wall of the case body and has a through hole. The first conductive member is inserted into the through hole and joined to the first electrode terminal.

[0007] According to the above configuration, the first conductive member 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 schematic diagram showing the configuration of the electrode body. [Figure 4] Figure 4 is a magnified view of the area near the positive terminal in Figure 2. [Figure 5] Figure 5 is a schematic plan view of the spacer. [Figure 6] Figure 6 is an explanatory diagram of the case preparation process and the insertion process. [Figure 7] Figure 7 is a modified version of Figure 5. [Figure 8] Figure 8 is a modified version of Figure 4. [Figure 9] Figure 9 is a diagram corresponding to Figure 4, relating to the first modified example. [Figure 10] Figures 10A and 10B are explanatory diagrams of the manufacturing process related to the first modified example. [Figure 11] Figure 11 is a diagram corresponding to Figure 4, relating to the second modified example. [Figure 12] Figures 12A and 12B are explanatory diagrams of the manufacturing process related to the second modified example. [Figure 13] Figure 13 is a diagram corresponding to Figure 4, relating to the third modified example. [Figure 14] Figure 14 is a diagram corresponding to Figure 4, relating to the fourth 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 the line II-II 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, the "power storage device" generally refers to all devices capable of repeated charge and discharge by the movement of charge carriers between a positive electrode and a negative electrode through an electrolyte. The electrolyte may be any of a liquid electrolyte (electrolytic solution), a gel electrolyte, or a solid electrolyte. The power storage device is a term that includes capacitors using chemical reactions such as lithium ion capacitors and pseudo-capacitance capacitors, in addition to secondary batteries such as lithium ion secondary batteries and nickel metal hydride secondary batteries.

[0012] As shown in FIG. 2, the power storage device 100 includes a case 10, an electrode body 20, a positive electrode terminal 30, a negative electrode terminal 40, a positive electrode current collector member 50, and a negative electrode current collector member 60. Here, the power storage device 100 further includes a spacer 80 and a liquid electrolyte (electrolytic solution, not shown). However, as described in the modification example (3) to be described later, the positive electrode current collector member 50, the negative electrode current collector member 60, and the spacer 80 are not essential and can be omitted in other embodiments. Here, the power storage device 100 is a non-aqueous electrolyte secondary battery. The power storage device 100 is preferably a secondary battery such as a lithium ion secondary battery.

[0013] The case 10 is a housing that houses the electrode body 20. As shown in FIG. 1, the case 10 has a flat and bottomed rectangular parallelepiped (rectangular) outer shape here. The material of the case 10 may be the same as those conventionally used and is not particularly limited. The case 10 is preferably made of metal, and more preferably made of, for example, aluminum, an aluminum alloy, iron, an iron alloy, or the like. As shown in FIG. 2, the case 10 includes a case body 12 and a sealing plate (lid) 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), and the like.

[0014] The case body 12 is a bottomed cylindrical shape having a bottom wall, side walls provided at the outer peripheral edge of the bottom wall, and an opening facing the bottom wall. Here, the case body 12 is a bottomed and rectangular container having an opening 12h on the upper surface. 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 sides 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 sides of the bottom wall 12a and facing each other, and an opening 12h (see FIG. 2) facing the bottom wall 12a, and is a bottomed rectangular cylindrical shape. The case body 12 is preferably a bottomed rectangular 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 shape" 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, and the like.

[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 continuously formed 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 examples 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-shaped member. The sealing plate 14 faces the bottom wall 12a of the case body 12. The sealing plate 14 is substantially rectangular in this case. The sealing plate 14 constitutes the top surface of the case 10. The case 10 is integrated by joining (e.g., welding) the sealing plate 14 to the periphery of the opening 12h of the case body 12. As shown in Figure 2, a joint (e.g., a welded joint) 10w is formed at the fitting portion between the case body 12 and the sealing plate 14. This seals (airtightly seals) the case 10.

[0018] As shown in Figures 1 and 2, the bottom wall 12a of the case body 12 is provided with an electrolyte injection hole 15, a gas discharge valve 17, and terminal lead-out holes 18 and 19. 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. The electrolyte injection hole 15 is sealed by a sealing member 16 after the electrolyte has been injected. The electrolyte injection hole 15 may also be provided on the sealing plate 14. The gas discharge valve 17 is a thin-walled portion configured to rupture when the pressure inside the case 10 exceeds a predetermined value, thereby discharging gas from inside the case 10 to the outside. The gas discharge valve 17 may also be provided on the sealing plate 14. The terminal lead-out holes 18 and 19 are formed at both ends of the long side direction Y of the bottom wall 12a, respectively. The terminal lead-out holes 18 and 19 penetrate the bottom wall 12a. As will be explained in more detail later, the positive terminal 30 and the negative terminal 40 are inserted through the terminal exit holes 18 and 19 of the bottom wall 12a, respectively.

[0019] 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 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 may 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).

[0020] Figure 3 is a schematic diagram showing the configuration of the electrode body 20. In Figure 3, 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.

[0021] As shown in Figure 3, 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."

[0022] As shown in Figure 3, 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).

[0023] As shown in Figure 3, 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 3). 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 made of a different material from the positive electrode 22. When the positive electrode 22 is the "first electrode," the positive electrode tab 22t is an example of the "first electrode tab."

[0024] 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. When the positive electrode 22 is the "first electrode," the positive electrode tab group 27 is an example of the "first electrode tab group."

[0025] As shown in Figure 3, 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.

[0026] As shown in Figure 3, 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, various additives, etc. 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.

[0027] As shown in Figure 3, 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).

[0028] As shown in Figure 3, 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 3) 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 3). 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 different component from the negative electrode 24. When the negative electrode 24 is the "first electrode," the negative electrode tab 24t is an example of the "first electrode tab."

[0029] 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. When the negative electrode 24 is the "first electrode," the negative electrode tab group 28 is an example of the "first electrode tab group."

[0030] As shown in Figure 3, 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, various additives, etc.

[0031] As shown in Figure 3, 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 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. 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.

[0032] 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.

[0033] 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 left end in Figures 1 and 2). The negative terminal 40 is attached to the other end of the long side direction Y of the bottom wall 12a (the right end in Figures 1 and 2). The positive terminal 30 is inserted through the terminal lead-out hole 18 of the bottom wall 12a, with a portion exposed to the outside of the case 10. The negative terminal 40 is inserted through the terminal lead-out hole 19 of the bottom wall 12a, with a portion exposed to the outside of the case 10. 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".

[0034] 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, it is possible to suppress a large load on the joint 10w even if an external force is applied to the terminals when the energy storage device 100 is in use. Therefore, the joint 10w becomes less susceptible to damage, and the sealing performance and reliability of the joint 10w can be improved.

[0035] As shown in Figures 1 and 2, the terminals (positive terminal 30 and / or negative terminal 40) are insulated from the bottom wall 12a of the case body 12 by an insulating member (in this case, a gasket 90). The terminals are fixed to the bottom wall 12a of the case body 12 via the gasket 90. The gasket 90 is preferably made of resin. The terminals may also be attached to the bottom wall 12a together with the gasket 90 by insert molding (integral molding). This increases the adhesion between the terminals, the gasket 90 and the bottom wall 12a, improving sealing performance and reliability. However, in other embodiments, the terminals may be fixed to the bottom wall 12a together with the gasket 90 by crimping or the like. For example, the terminals can be fixed to the case body 12 by connecting them to an external conductive member located on the outside of the case body 12 by crimping and / or welding. Alternatively, the terminals can be fixed to the case body 12 by crimping and / or welding to an internal conductive member located on the inside of the case body 12. Alternatively, they may be fixed to the bottom wall 12a via an adhesive layer (such as an adhesive).

[0036] 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 term "positive electrode" below can be appropriately replaced with "negative electrode". The technology disclosed herein is more preferably applied to both the positive electrode 22 side and the negative electrode 24 side.

[0037] Figure 4 is a magnified view of the vicinity of the positive electrode terminal 30. The positive electrode terminal 30 is inserted through a terminal lead-out hole 18 in the bottom wall 12a and extends from the inside (upper side of Figure 4) to the outside (lower side of Figure 4) of the case body 12. A portion of the positive electrode terminal 30 protrudes from the terminal lead-out hole 18 to the outer surface of the bottom wall 12a and is exposed to the outside of the case 10. The positive electrode terminal 30 is electrically connected to the positive electrode 22 of the electrode body 20. As shown in Figure 4, the positive electrode terminal 30 is electrically connected to the positive electrode 22 of the electrode body 20 via a positive electrode current collector 50 and a group of positive electrode tabs 27 (a plurality of positive electrode tabs 22t). 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. The positive terminal 30 further comprises a cylindrical portion 31, an outer flange portion 32, and an inner flange portion 33.

[0038] The cylindrical portion 31 is the part located inside the terminal exit hole 18. The cylindrical portion 31 extends in the vertical direction Z. Although not shown in the figure, the cylindrical portion 31 is annular in XY plan view. That is, the outer shape of the cylindrical portion 31 is cylindrical. The outer flange portion 32 is connected to the lower end of the cylindrical portion 31 (the end on the outer surface side of the bottom wall 12a) and is a part with a larger outer shape than the cylindrical portion 31. The outer flange portion 32 is located outside the case body 12 (on the outer surface side of the bottom wall 12a) of the terminal exit hole 18. As shown in Figure 1, the outer flange portion 32 is approximately rectangular in XY plan view. The inner flange portion 33 is connected to the upper end of the cylindrical portion 31 (the end on the electrode body 20 side) and is a part with a larger outer shape than the cylindrical portion 31. The inner flange portion 33 is positioned on the inside side (electrode body 20 side) of the case body 12 than the terminal lead-out hole 18. A spacer 80, which will be described later, is in contact with the inner flange portion 33. The outer shape of the outer flange portion 32 or the inner flange portion 33 can be larger than the inner diameter of the terminal lead-out hole 18. Also, the shape of the outer flange portion 32 and the inner flange portion 33 in plan view may be circular.

[0039] The through-hole 30h penetrates the positive terminal 30 in the vertical direction Z. The through-hole 30h extends from the inside to the outside of the case body 12. The through-hole 30h is provided along the terminal lead-out hole 18. As can be seen from Figures 1 and 4, the through-hole 30h is formed in a cylindrical shape here. Preferably, the through-hole 30h is circular in XY plan view. In the XY plan view, the center of the through-hole 30h coincides with the center of the outer flange 32 of the positive terminal 30. In the XY plan view, the center of the through-hole 30h coincides with the center of the inner flange 33 of the positive terminal 30. The positive current collector member 50 (specifically the second connection part 52), which will be described later, is inserted through the through-hole 30h.

[0040] The positive electrode current collector 50 is a conductive member 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 type of metal as the positive electrode tab 22t and / or the positive electrode terminal 30. As shown in Figure 4, the positive electrode current collector 50 has a first connection part 51 and a second connection part 52. When the positive electrode 22 is the "first electrode", the positive electrode current collector 50 is an example of the "first conductive member".

[0041] The first connection portion 51 is provided at the upper end (the end on the electrode body 20 side) of the positive electrode current collector member 50. The first connection 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 first connection portion 51 is joined (for example, by welding such as ultrasonic welding) to the positive electrode tab group 27 (multiple positive electrode tabs 22t). The first connection portion 51 is flat in shape and extends along the inner surface of the bottom wall 12a. As shown in Figure 4, in the long side direction Y, the width of the first connection portion 51 is wider than the width of the positive electrode tab group 27. The width of the first connection portion 51 is wider than the width of the through hole 30h of the positive electrode terminal 30.

[0042] The second connection portion 52 is provided at the lower end (the end on the bottom wall 12a side) of the positive electrode current collector member 50. The second connection portion 52 is located on the opposite side of the positive electrode tab group 27, with the first connection portion 51 in between. The second connection portion 52 is located in a position that overlaps with the positive electrode tab group 27 in an XY plan view. The second connection portion 52 is inserted into the through hole 30h of the positive electrode terminal 30. As can be seen from Figures 1 and 4, the second connection portion 52 here is columnar, specifically cylindrical. It is preferable that the second connection portion 52 be circular in an XY plan view. If both the second connection portion 52 of the positive electrode current collector member 50 and the through hole 30h of the positive electrode terminal 30 are circular in an XY plan view, the insertability of the second connection portion 52 and the airtightness of the through hole 30h after the second connection portion 52 is inserted can be improved. This, in turn, can improve the reliability of the energy storage device 100.

[0043] The second connecting portion 52 is smaller than the through-hole 30h of the positive terminal 30 and is inserted through the through-hole 30h of the positive terminal 30. This can increase the contact area between the positive terminal 30 and the positive current collector 50. Therefore, it becomes easier to maintain a more stable electrical connection between the positive terminal 30 and the positive current collector 50, and the conductivity reliability can be improved. However, the second connecting portion 52 only needs to be configured to be insertable into the through-hole 30h, and in other embodiments it may be a protruding portion or the like. Also, as described in the modified example (3) below, the second connecting portion 52 may be flat.

[0044] The second connecting portion 52 here extends from the inside to the outside of the case 10. The lower end of the second connecting portion 52 here is exposed to the outside of the case body 12 (the outer surface side of the bottom wall 12a). The lower end of the second connecting portion 52 here is contained within the through hole 30h. The lower end surface of the second connecting portion 52 here is substantially flush with the outer flange portion 32 of the positive terminal 30 (allowing for manufacturing tolerances, etc.). The second connecting portion 52 here does not protrude from the through hole 30h. However, as described in the modified example (3) below, the second connecting portion 52 may protrude from the through hole 30h.

[0045] The positive electrode current collector 50 is joined to the positive electrode terminal 30. In this embodiment, as shown in Figure 4, the periphery of the through hole 30h of the positive electrode terminal 30 and the second connection 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.

[0046] 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 second connection 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.

[0047] In this embodiment, the positive electrode 22 and the positive electrode terminal 30 are electrically connected via the positive electrode current collector 50, which is a conductive member. However, as described in the modified example (3) below, in other embodiments, the positive electrode 22 may be electrically connected to the positive electrode terminal 30 not via the positive electrode current collector 50, but for example, only via the group of positive electrode tabs 27, which are conductive members.

[0048] The negative electrode terminal 40 is electrically connected to the negative electrode 24 of the electrode body 20. 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 (see Figure 6). 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 and the negative electrode tab group 28 (multiple negative electrode tabs 24t). The negative electrode terminal 40 is preferably made of metal, and more preferably of copper or a copper alloy.

[0049] 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. The negative electrode current collector 60 has a first connection part 61 and a second connection part 62 (see Figure 6). When the negative electrode 24 is the "first electrode", the negative electrode current collector 60 is an example of the "first conductive member".

[0050] As shown in Figure 2, the spacer 80 is positioned inside the case 10 between the bottom wall 12a (specifically the inner surface, the upper surface in Figure 2) and the electrode body 20 (specifically the lower surface in Figure 2). As shown in Figure 4, the spacer 80 is positioned here between the inner flange 33 of the positive electrode terminal 30 fixed to the bottom wall 12a and the first connection portion 51 of the positive electrode current collector member 50. The spacer 80 is typically insulating and preferably made of resin. The material of the spacer 80 may be the same as that exemplified as the material of the electrode body holder 29. The spacer 80 is a single component here. However, the spacer 80 may consist of multiple components, for example, positioned at spaced distances from each other. For example, a first spacer and a second spacer can be positioned on the positive electrode terminal 30 side and the negative electrode terminal 40 side, respectively.

[0051] Figure 5 is a schematic plan view of the spacer 80. In Figure 5, 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. As shown in Figure 5, the spacer 80 has a flat base portion 89 and a pair of end through holes 85 and 86. The spacer 80 also has a central through hole 81.

[0052] As shown in Figure 2, the base portion 89 extends along the bottom wall 12a of the case body 12. In an XY plan view, the outer shape of the base portion 89 is preferably approximately the same as or larger than the outer shape of the electrode body 20. As shown in Figure 5, in an XY plan view, the outer edge of the spacer 80 (more specifically the base portion 89) is preferably in contact with or 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.

[0053] As shown in Figure 2, the central through-hole 81 is located in the portion opposite to the electrolyte injection hole 15 and the gas discharge valve 17 (the portion that overlaps in the XY plane view). As a result, in the vertical Z direction, the electrolyte injection hole 15 and the gas discharge valve 17 are directly opposite to the electrode body 20 (or electrode body holder 29), respectively. The positive electrode current collector 50 (specifically, the columnar second connecting portion 52) is inserted through the end through-hole 85. The negative electrode current collector 60 (specifically, the columnar second connecting portion 62) is inserted through the end through-hole 86. As a result, the spacer 80 is integrated (connected) with the electrode body 20 and the conductive members (positive electrode current collector 50 and / or negative electrode current collector 60).

[0054] The spacer 80 has an outer shape that is approximately the same as the inner surface of the side wall of the case body 12, and has end through holes 85 and 86 through which the conductive members (positive electrode current collector 50 and / or negative electrode current collector 60) are inserted, making it easier to guide the electrode body 20 and the conductive members to the desired position in the insertion step (step 2) of the manufacturing method described later. In other words, the spacer 80 can also function as a guide member for the electrode body 20 and a positioning member for the conductive members. Consequently, in the joining step (step 3) of the manufacturing method described later, it becomes easier to stably bring the conductive members into contact with the terminals (positive electrode terminal 30 and / or negative electrode terminal 40) and join them.

[0055] [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) Insertion step; (Step 3) Joining step; (Step 4) 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 performed substantially simultaneously. Similarly, the order of (Step 3) Joining step and (Step 4) Sealing step is not particularly limited and may be reversed or performed substantially simultaneously. Furthermore, the manufacturing method disclosed herein may include other steps at any stage. For example, after (Step 4) Sealing step, a step of pouring electrolyte into the case 10 may be included. Figure 6 is an explanatory diagram of (Step 1A) Case preparation step and (Step 2) Insertion step. Note that in Figure 6, the bottom wall 12a of the case body 12 is in an inverted position facing vertically upward, taking into consideration the workability in the (Step 3) Joining step described later.

[0056] (Step 1A) In the case preparation step, the case body 12 and the sealing plate 14 are prepared. Specifically, the case body 12 is a bottomed cylindrical case body having a bottom wall 12a, side walls 12b and 12c and an opening 12h, and the sealing plate 14 seals the opening 12h. 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, it is preferable that the case body 12 has terminals (positive terminal 30 and / or negative terminal 40) pre-attached to the bottom wall 12a, as shown in the upper part of Figure 6. It is preferable that the terminals are attached to the bottom wall 12a in an insulated state from the bottom wall 12a via an insulating member (here, a gasket 90). The method of attaching the terminals is not particularly limited. Here, the terminals are pre-attached to the bottom wall 12a together with the gasket 90 by insert molding (integral molding).

[0057] In other words, the case body 12 is prepared as a single molded product integrated with the gasket 90 and terminals (positive terminal 30 and / or negative terminal 40). However, in other embodiments, the terminals may be attached to the bottom wall 12a by crimping (riveting) or the like, or they may be attached to the bottom wall 12a via an adhesive layer (adhesive, etc.). Also, as described in the modified example (4) below, the terminals do not necessarily have to be attached to the bottom wall 12a beforehand; for example, they can be attached to the bottom wall 12a in an insertion process or joining process described later.

[0058] (Step 1B) In the electrode preparation step, the electrode body 20 is prepared. The electrode body 20 may be a purchased product 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 longitudinally around a winding axis WL 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 flat to produce a flat-shaped electrode body 20. Then, multiple positive electrode tabs 22t are bundled together, preferably by joining the positive electrode tabs 22t together to form a group of positive electrode tabs 27. Similarly, multiple negative electrode tabs 24t are bundled together, preferably by joining the negative electrode tabs 24t together to form a group of negative electrode tabs 28.

[0059] (Step 2) In the insertion step, after the case preparation step, the electrode body 20 with the conductive members (positive electrode current collector 50 and / or negative electrode current collector 60) attached is inserted into the case body 12, and at least a portion of the conductive members is inserted into the through holes 30h of the terminals (positive electrode terminal 30 and / or negative electrode terminal 40). In some embodiments, before inserting the electrode body 20 into the case body 12, an assembly including the electrode body 20, conductive members and spacers 80 is first prepared, as shown in the lower part of Figure 6.

[0060] Specifically, for example, the first connection portion 51 of the positive electrode current collector 50 is attached to the positive electrode tab group 27 of the electrode body 20 by welding, such as ultrasonic welding, resistance welding, or laser welding. Similarly, the first connection portion 61 of the negative electrode current collector 60 is attached to the negative electrode tab group 28 of the electrode body 20. This integrates (connects) the electrode body 20 and the conductive members (positive electrode current collector 50 and / or negative electrode current collector 60). Then, the electrode body 20 is covered with an electrode body holder 29 (such as a resin sheet).

[0061] Next, a spacer 80 having end through holes 85 and 86 is prepared, and the spacer 80 is connected to the conductive member. Here, the columnar second connection portion 52 of the positive electrode current collector member 50 and the columnar second connection portion 62 of the negative electrode current collector member 60 are inserted through the end through holes 85 and 86 of the spacer 80, respectively. As a result, the electrode body 20 is integrated (connected) with the spacer 80. The spacer 80 is placed on the first connection portion 51 of the positive electrode current collector member 50 and the first connection portion 61 of the negative electrode current collector member 60.

[0062] In this embodiment, the two members are integrated (connected) by inserting the columnar second connecting portion 52 of the positive electrode current collector member 50 and the columnar second connecting portion 62 of the negative electrode current collector member 60 through the end through holes 85 and 86 of the spacer 80, but the method of integration is not limited to this. In other embodiments, the spacer 80 may have, instead of or in addition to the end through holes 85 and 86, a portion (for example, a fitting recess or a fixing claw portion) to which the first connecting portion 51 of the positive electrode current collector member 50 and / or the first connecting portion 61 of the negative electrode current collector member 60 are positioned. The spacer 80 and the conductive members (positive electrode current collector member 50 and / or negative electrode current collector member 60) may then be integrated (connected) via the fitting recess or fixing claw portion.

[0063] Next, as shown by the arrows in Figure 6, the electrode body 20, integrated with the spacer 80, is inserted into the case body 12. More specifically, the electrode body 20 is inserted through the opening 12h of the case body 12 so that the side with the conductive members (positive electrode current collector 50 and / or negative electrode current collector 60) attached faces the bottom wall 12a. 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 of the case body 12 (a pair of long side walls 12b and a pair of short side walls 12c). Therefore, 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 can function as a guide member that guides the electrode body 20 to a desired position.

[0064] In this embodiment, as the spacer 80 moves along the side walls 12b and 12c of the case body 12 towards the bottom wall 12a, the conductive members (positive electrode current collector 50 and negative electrode current collector 60) also move towards the bottom wall 12a, and at least a portion of the conductive members is inserted into the through holes 30h and 40h of the terminals (positive electrode terminal 30 and negative electrode terminal 40). Specifically, the columnar second connecting portion 52 of the positive electrode current collector 50 is inserted through the through hole 30h of the positive electrode terminal 30. Similarly, the columnar second connecting portion 62 of the negative electrode current collector 60 is inserted through the through hole 40h of the negative electrode terminal 40. This allows the conductive members to be 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 also function as a positioning member that guides the conductive members to a desired joining position. In this embodiment, the end face of the second connection portion 52 of the positive electrode current collector 50 is flush with the outer flange portion 32 of the positive electrode terminal 30.

[0065] In this embodiment, as shown in Figure 6, 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.

[0066] (Step 3) In the joining process, after the insertion process, the conductive members (positive electrode current collector 50 and / or negative electrode current collector 60) and the terminals (positive electrode terminal 30 and / or negative electrode terminal 40) are joined. In this embodiment, with the bottom wall 12a facing upward in an inverted position, the electrode body 20 is pressed from the opening 12h side and pressed against the bottom wall 12a side, maintaining the state in which the second connecting portion 52 of the positive electrode current collector 50 is inserted into the through hole 30h of the positive electrode terminal 30. Preferably, the end face of the second connecting portion 52 and the periphery of the through hole 30h of the positive electrode terminal 30 are kept substantially flush. This allows the positive electrode current collector 50 and the positive electrode terminal 30 to be brought into contact. Then, the portion where the second connecting portion 52 of the positive electrode current collector 50 inserted into the through hole 30h and the positive electrode terminal 30 come into contact is joined. In this embodiment, the tip of the second connecting portion 52 of the positive electrode current collector 50 and the outer flange portion 32 of the positive electrode terminal 30 are joined at the periphery of the through hole 30h of the positive electrode terminal 30. This allows the positive electrode current collector 50 and the positive electrode terminal 30 to be stably joined.

[0067] The joining method is not particularly limited. In some embodiments, it is preferable to weld the case body 12 by irradiating it with an energy ray such as a laser 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 conductive member and the terminal more stably. In this embodiment, an annular (e.g., circular) joint J is formed along the through hole 30h.

[0068] (Step 4) 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.

[0069] [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).

[0070] 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.

[0071] (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.

[0072] 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.

[0073] (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 another conductive member (positive electrode current collector 50 and / or negative electrode current collector 60) as an electrode tab.

[0074] (2) Spacer: (2-1) For example, in the embodiment of Figure 5 described above, the outer edge of the spacer 80 (more specifically, the base portion 89) was in contact with or close to the entire circumference of the side walls of the case body 12 (a pair of long side walls 12b and a pair of short side walls 12c). However, it is not limited to this. Figure 7 is a modified diagram corresponding to Figure 5. The spacer 180 shown in Figure 7 has a flat base portion 189, a central through hole 181, and end through holes 185 and 186, and further includes a first extension portion 189b extending from the base portion 189 toward an opposing pair of long side walls 12b, and a second extension portion 189c extending from the base portion 189 toward an opposing pair of short side walls 12c. In the spacer 180, the first extension portion 189b and the second extension portion 189c are in contact with or close to a part of the side wall of the case body 12. Even a spacer 180 of this form can function adequately as a guide member for the electrode body 20 or as a positioning member for the conductive member, as described above.

[0075] (2-2) In the embodiment described above, for example, the base portion 89 of the spacer 80 was flat. However, the invention is not limited to this. Figure 8 is a modified example corresponding to Figure 4. As shown in Figure 8, the spacer 280 is provided on the periphery of the positive electrode terminal 30 and the group of positive electrode tabs 27 and has a thin-walled region A1 with a relatively thin thickness, and is provided at a position away from the positive electrode terminal 30 and the group of positive electrode tabs 27 and has a relatively thick-walled region A2. This makes it possible to secure a gap between the electrode body 20 and the bottom wall 12a of the case body 12 on the periphery of the positive electrode terminal 30 and the group of positive electrode tabs 27. With this configuration, when the bottom wall 12a of the case body 12 is positioned vertically downward during the manufacture or use of the energy storage device 100, the weight of the electrode body 20 is applied to the thick-walled region A2, as shown by the arrow in Figure 8. Therefore, damage to the conductive path and the part to which the positive electrode terminal 30 is attached due to the weight of the electrode body 20 can be effectively suppressed. Furthermore, even if external forces such as vibration or shock are applied when the energy storage device 100 is in use, the electrode body 20 will be less likely to move toward the bottom wall 12a.

[0076] In the modified example shown in Figure 8, the gap between the electrode body 20 and the bottom wall 12a is divided into two sections in the vertical direction Z by the thin-walled region A1 of the spacer 280. Specifically, in the vertical direction Z, a first space S1 is secured between the electrode body 20 and the thin-walled region A1 of the spacer 280, and a second space S2 is secured between the thin-walled region A1 of the spacer 280 and the bottom wall 12a. By securing the first space S1, damage to the positive electrode tab group 27 can be effectively suppressed, and conductivity reliability can be improved. Furthermore, by securing the second space S2, the contact between the portion to which the positive electrode terminal 30 is attached, particularly the bottom wall 12a, the gasket 90, and the positive electrode terminal 30, can be easily maintained, improving sealing performance and reliability.

[0077] While not particularly limited, the thickness T1 of the thick-walled region A2 (perpendicular length to the bottom wall 12a) is preferably 0.5 times or more, more preferably 0.6 times or more, and even more preferably 0.7 times or more, the distance D1 from the end face of the electrode body 20 on the bottom wall 12a side to the bottom wall 12a. In addition, in the long side direction Y, the width of the thin-walled region A1 is preferably longer than the width of the positive electrode tab group 27, and more preferably longer than the width of the first connection portion 51 of the positive electrode current collector member 50. Furthermore, the thickness T1 of the thick-walled region A2 is preferably 2 times or more, and more preferably 3 times or more, the thickness of the thin-walled region A1.

[0078] (2-3) In addition, for example, in the embodiment described above, the spacer 80 functioned as a positioning member for the conductive members (positive electrode current collector 50 and / or negative electrode current collector 60). However, the method of positioning the conductive members is not limited to this. The spacer 80 does not have to function as a positioning member. In a modified example, the electrode holder 29 may function as a positioning member for the conductive members. In this case, it is preferable that the outer edge of the electrode body 20 enclosed in the electrode holder 29 abuts against or is close to the inner surface of the side wall of the case body 12. The gap between the outer edge of the electrode body 20 enclosed in the electrode holder 29 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 electrode holder 29) is preferably 1 mm or less, more preferably 0.8 mm or less, and even more preferably 0.5 mm or less. Furthermore, it is preferable that the electrode holder 29 has an end through-hole on the side where the conductive members (positive electrode current collector 50 and / or negative electrode current collector 60) are arranged, and that the conductive members (more specifically, the second connecting portion inserted into the terminal through-hole) pass through the end through-hole.

[0079] (3) Conduction path: The joint J is not limited to the embodiment shown in Figure 4. The joint J may be formed inside the through hole 30h. The conductive path can also be modified as shown in the first to third modifications below.

[0080] (3-1) First variation Figure 9 is a diagram corresponding to Figure 4 relating to the first modified example. As shown in Figure 9, in this modified example, the inner flange portion 133 of the positive electrode terminal 130 has a chamfered portion 133c at the corner on the through hole 130h side (the side connected to the cylindrical portion 131). This can improve the ease of insertion when inserting the positive electrode current collector member 150 (specifically the second connection portion 152) into the through hole 130h. The chamfered portion 133c is formed continuously in the circumferential direction of the through hole 130h. The shape of the chamfered portion 133c is not particularly limited, but for example, it can be a C-shaped chamfer with the corner cut off at a predetermined angle (e.g., 45 degrees), or an R-shaped chamfer with the corner rounded.

[0081] In this modified example, the outer flange portion 132 of the positive terminal 130 has a recess 132r provided on the side of the case body 12 furthest from the bottom wall 12a (the lower side in Figure 9), and a stepped portion 132s provided within the recess 132r. The positive terminal 130 also has a cover member 139 in this example. Although the cover member 139 is part of the positive terminal 130 in this example, the cover member 139 does not have to be part of the positive terminal 130.

[0082] The recess 132r is provided around the through hole 130h so as to surround the through hole 130h. In an XY plan view, the outer shape of the recess 132r is approximately annular (specifically, approximately circular). In an XY plan view, the center of the recess 132r coincides with the center of the through hole 130h. The outer diameter of the recess 132r is larger than that of the through hole 130h. The outer diameter of the recess 132r is also larger than that of the inner flange portion 133. The stepped portion 132s is provided on the inner surface of the recess 132r. In a plan view, the outer shape of the stepped portion 132s is approximately annular (specifically, approximately circular). The cover member 139 is fitted into the stepped portion 132s. The stepped portion 132s also functions as a guide to indicate the position for fitting the cover member 139.

[0083] In this modified example, a joint J1 between the positive electrode current collector 150 (first conductive member) and the positive electrode terminal 130 (first electrode terminal) is provided within the recess 132r. More specifically, the joint J1 is provided on the bottom surface of the recess 132r (a part of the outer flange portion 132, which is the surface facing the cover member 139). The joint J1 may be provided continuously in the circumferential direction (ring-shaped) along the boundary portion between the positive electrode terminal 130 and the second connection portion 152 of the positive electrode current collector 150, or it may consist of a plurality of spot joints arranged at spaced-apart positions in the circumferential direction. By arranging the joint J1 within the recess 132r, the joint J1 is less likely to protrude toward the outer surface side of the bottom wall 12a. Therefore, interference between the joint J1 and other members, resulting in damage or breakage, can be suppressed.

[0084] The cover member 139 is positioned to cover the joint J1 between the positive terminal 130 and the positive current collector 150. The cover member 139 is a plate-shaped member in this case. The cover member 139 is conductive and preferably made of metal, and may be made of the same type of metal as the outer flange 132, for example. The outer shape of the cover member 139 is approximately circular. The cover member 139 seals the opening of the recess 132r. Having the cover member 139 ensures a more reliable seal inside the case 10. The cover member 139 is fitted into the stepped portion 132s in this case. The outer surface of the cover member 139 is approximately flush with the lower end surface of the outer flange 132 (more specifically, the outer peripheral edge of the recess 132r).

[0085] A joint (e.g., a welded joint) 139w is formed at the fitting portion between the outer peripheral edge of the recess 132r and the cover member 139. The joint 139w is annular (e.g., circular) and is continuously provided around the entire circumference at the boundary between the outer peripheral edge of the recess 132r and the cover member 139. As a result, the recess 132r is airtightly sealed. In order to improve the sealing performance of the fitting portion, a sealing member made of rubber or resin may be placed on the portion of the outer flange 132 that abuts against the cover member 139 (e.g., the outer peripheral edge of the stepped portion 132s).

[0086] In this case, the cover member 139 is entirely housed within the recess 132r. By positioning the cover member 139 within the recess 132r, the protruding height of the cover member 139 can be suppressed. Furthermore, it is possible to prevent the cover member 139 and the joint portion 139w from interfering with other members and being damaged or broken.

[0087] In this modified example, the cover member 139 is flat and attached to the opening of the recess 132r, but the configuration of the cover member is not limited to this. The cover member may be cup-shaped, for example, having a convex portion and an outer edge portion provided around the entire circumference of the convex portion. A space is formed inside the convex portion. In this case, the convex portion of the cover member may be placed over the joint J1 between the positive terminal 130 and the positive current collector 150, and the outer edge portion of the cover member may be joined (for example, by welding) to the outer flange portion 132 around the joint J1.

[0088] In this modified example, as shown in Figure 9, no spacer is placed between the bottom wall 12a and the electrode body 120. Here, the inner flange portion 133 of the positive electrode terminal 130 fixed to the bottom wall 12a and the first connection portion 151 of the positive electrode current collector 150 are in direct contact even inside the case body 12. However, as with the embodiment shown in Figure 4 above, a spacer may be placed between the bottom wall 12a and the electrode body 120.

[0089] The manufacturing process for this modified example further includes (Step 3X) the cover attachment step in addition to (Step 3) the joining step of the embodiment described above. Figures 10A and 10B are explanatory diagrams of the manufacturing process for the first modified example. In Figures 10A and 10B, the vicinity of the positive electrode terminal 130, which is a key part, is partially enlarged. Also, in this example, the bottom wall 12a of the case body 12 is in an inverted position facing upward in the vertical direction. In this modified example, as shown in Figure 10A, a positive electrode current collector 150 as a conductive member is attached to the electrode body 120 (more specifically, the positive electrode tab group 127). More specifically, the positive electrode tab group 127 of the electrode body 120 is positioned offset from the second connection part 152 of the first connection part 151. The positive electrode tab group 127 is positioned so as not to overlap with the second connection part 152 in an XY plan view. For example, by joining the positive electrode tab group 127 to a flat plate-shaped region of the first connection portion 151 where the second connection portion 152 is not formed, the first connection portion 151 and the positive electrode tab group 127 can be stably joined by ultrasonic bonding or the like.

[0090] (Step 2) In the insertion step, for example, the case body 12 is inverted so that the bottom wall 12a faces vertically upward, and the columnar second connecting portion 152 of the positive electrode current collector member 150 is inserted into the through hole 130h of the positive electrode terminal 130, as shown by the arrow in Figure 10A. As shown in Figure 10B, the end face of the second connecting portion 152 inserted into the through hole 130h is substantially flush with the bottom surface of the recess 132r. The tip of the second connecting portion 152 does not protrude into the recess 132r, or is positioned within the recess 132r.

[0091] (Step 3) In the joining process, the positive electrode current collector 150 (first conductive member) and the positive electrode terminal 130 (first electrode terminal) are joined within the recess 132r. Specifically, the end face of the second connection portion 152 of the positive electrode current collector 150 inserted into the through hole 130h and the outer flange portion 132 of the positive electrode terminal 130 are joined at the point where they come into contact. The joining may be performed continuously in the circumferential direction along the boundary between the positive electrode terminal 130 and the positive electrode current collector 150, or it may be performed intermittently in the circumferential direction as spot joining. This forms a joint portion J1 (see Figure 9) within the recess 132r.

[0092] (Step 3X) In the cover mounting process, after the joining process, the joint J1 between the positive electrode current collector 150 (first conductive member) and the positive electrode terminal 130 (first electrode terminal) is covered with the cover member 139. Specifically, the cover member 139 is fitted into the stepped portion 132s of the recess 132r, and the outer peripheral edge of the recess 132r and the cover member 139 are joined. The joining method is not particularly limited. In some embodiments, it is preferable to weld the joint by irradiating the fitting portion between the outer flange portion 132 and the cover member 139 along the periphery of the recess 132r with an energy ray such as a laser. It is preferable to perform the joining continuously in the circumferential direction along the boundary portion between the outer flange portion 132 and the cover member 139. This forms the joint portion 139w (see Figure 9), and the recess 132r is sealed.

[0093] (3-2) Second variation Figure 11 is a diagram corresponding to Figure 4 relating to the second modified example. As shown in Figure 11, in this modified example, a positive electrode current collector 250 is attached to the electrode body 220 (specifically, the positive electrode tab group 227) as a conductive member. Unlike the first modified example described above, the positive electrode current collector 250 is made by bending a plate-shaped member. Other than this, this modified example is the same as the first modified example described above. In this modified example, in order to more reliably ensure airtightness, it is preferable that the positive electrode terminal 230 has a cover member 239, similar to the first modified example described above.

[0094] The positive electrode current collector 250 of this modified example has a first connection portion 251 and a second connection portion 252. The second connection portion 252 has an extended portion 252e that extends from the first connection portion 251 and is inserted into the through hole 230h of the positive electrode terminal 230, and a bent portion 252b that is bent from the extended portion 252e. The extended portion 252e extends along the through hole 230h. The bent portion 252b here extends along the first connection portion 251 (approximately horizontal to the first connection portion 251). The bent portion 252b abuts against the bottom surface of the recess 232r of the positive electrode terminal 230. The bent portion 252b is joined to the bottom surface of the recess 232r (part of the outer flange portion 232) outside the case body 12. A joint J2 between the positive electrode terminal 230 and the positive electrode current collector 250 (conductive member) is provided on the bottom surface of the recess 232r.

[0095] The manufacturing process for this modified example further includes a (step 2X) bending step after the (step 2) insertion step of the first modified example described above. Figures 12A and 12B are explanatory diagrams of the manufacturing process for the first modified example. In Figures 12A and 12B, the vicinity of the positive electrode terminal 230, which is a key part, is partially enlarged. Also, in this example, the bottom wall 12a of the case body 12 is in an inverted position facing upward in the vertical direction. In this modified example, in the (step 2) insertion step, as shown in Figure 12A, the flat second connecting portion 252 of the positive electrode current collector member 250 is inserted into the through hole 230h of the positive electrode terminal 230. The tip of the second connecting portion 252 protrudes from the through hole 230h and extends into the recess 232r.

[0096] (Step 2X) In the bending process, after the insertion process, the positive electrode current collector 250 (first conductive member) is deformed as shown in Figure 12B. Specifically, the portion (tip portion) protruding from the through hole 230h of the second connection portion 252 is bent. Here, the tip portion of the second connection portion 252 is bent in an approximately L-shape with respect to the bottom surface of the recess 232r. As a result, a bent portion 252b is formed at the tip of the extended portion 252e.

[0097] (Step 3) In the joining process, after the bending process, the deformed positive electrode current collector 250 is brought into contact with the positive electrode terminal 230 (first electrode terminal) and joined to the positive electrode terminal 230. Specifically, the bent portion 252b of the positive electrode current collector 250 is brought into contact with the bottom surface of the recess 232r of the positive electrode terminal 230 and joined to the outer flange portion 232 (see Figure 11). This forms a joint portion J2 (see Figure 11) within the recess 232r. By providing the bent portion 252b as in this modified example, the positive electrode current collector 250 and the positive electrode terminal 230 can be joined more stably. Furthermore, even if an external force is applied when the energy storage device 100 is in use, the second connection portion 252 can bend and absorb the external force, thereby reducing the load on the joint portion J2. Consequently, the conductivity reliability of the joint portion J2 can be improved.

[0098] (Step 3X) In the cover mounting process, after the joining process, the cover member 239 is fitted into the stepped portion 232s (see Figure 11) of the recess 232r, similar to the first modified example described above, and the outer flange portion 232 and the cover member 239 are joined along the periphery of the recess 232r, thereby forming the joint portion 239w (see Figure 11).

[0099] (3-3) Third Variation Figure 13 is a diagram corresponding to Figure 4 relating to the third modified example. As shown in Figure 13, in this modified example, the positive electrode terminal 330 has a cylindrical portion 331, an outer flange portion 332, and a through hole 330h. The positive electrode terminal 330 here does not have an inner flange portion. Also in this modified example, the positive electrode current collector is not attached to the electrode body 320 (without the interposition of a positive electrode current collector), and a group of positive electrode tabs 327, composed of multiple positive electrode tabs 322t, is directly inserted into the through hole 330h of the positive electrode terminal 330. In this modified example, the group of positive electrode tabs 327 is an example of the "first conductive member".

[0100] The protruding length (vertical length protruding from the base) of the positive electrode tab 22t can be, for example, 5 mm or more, or 10 mm or more. Multiple positive electrode tabs 322t may be joined together by welding or the like to form a single unit before being inserted into the through hole 330h of the positive electrode terminal 330. In this modified example, in order to more reliably ensure airtightness, it is preferable that the positive electrode terminal 330 has a cover member 339, similar to the first and second modified examples described above.

[0101] The positive electrode tab group 327 is inserted into the through hole 330h of the positive electrode terminal 330. The positive electrode tab group 327 has an extended portion 327e and a bent portion 327b that is bent from the extended portion 327e, similar to the second connection portion 252 of the positive electrode current collector member 250 in the second modified example. The bent portion 327b abuts against the bottom surface of the recess 332r of the positive electrode terminal 330. The bent portion 327b is joined to the positive electrode terminal 330. Specifically, the bent portion 327b is joined to the bottom surface of the recess 332r (part of the outer flange portion 332) outside the case body 12. A joint portion J3 between the positive electrode terminal 330 and the positive electrode tab group 327 (conductive member) is provided on the bottom surface of the recess 332r.

[0102] The manufacturing process for this modified example may be the same as that for the second modified example, except that the conductive member (positive electrode current collector 250) is a group of positive electrode tabs 327. For example, in (step 2) insertion step, the group of positive electrode tabs 327 (first electrode tab group) is inserted into the through hole 330h of the positive electrode terminal 330 (first electrode terminal); in (step 2X) bending step, the group of positive electrode tabs 327 is deformed to form a bent portion 327b at the tip of the extended portion 327e; and in (step 3) joining step, the bent portion 327b of the group of positive electrode tabs 327 is brought into contact with the positive electrode terminal 330 to join it with the positive electrode terminal 330. Furthermore, in the (Step 3X) cover mounting process, similar to the first and second modified examples described above, the cover member 339 is fitted into the stepped portion 332s of the recess 332r, and the outer flange portion 332 and the cover member 339 are joined along the periphery of the recess 332r, thereby forming the joint portion 339w.

[0103] In this modified example, the positive electrode tab group 327 is directly joined to the positive electrode terminal 330, but for example, another (second) conductive member may be attached to the tip of the bent portion 327b, and this second conductive member may be joined to the positive electrode terminal 330. By providing the bent portion 252b as in this modified example, the positive electrode tab group 327 or the second conductive member connected thereto can be made to contact the positive electrode terminal 30 more stably. Furthermore, even if an external force is applied when the energy storage device 100 is in use, the load on the joint J3 can be reduced. Consequently, the conductivity reliability of the joint J3 can be improved.

[0104] In this modified example, similar to the embodiment shown in Figure 4 above, a spacer 380 is positioned between the bottom wall 12a of the case body 12 and the electrode body 320. A portion of the spacer 380 is positioned within the through-hole 330h of the positive electrode terminal 330. That is, the spacer 380 has a support portion 380s that supports at least a portion of the positive electrode tab group 327. The support portion 380s extends from the base portion 389 of the spacer 380 along the positive electrode tab group 327 (specifically the extended portion 327e). The support portion 380s does not protrude into the recess 332r in this example. The support portion 380s is inserted into the through-hole 330h of the positive electrode terminal 330 while supporting at least a portion of the positive electrode tab group 327. This prevents damage or breakage of the positive electrode tab group 327.

[0105] (3-4) Fourth variation Figure 14 is a diagram corresponding to Figure 4 relating to the fourth modified example. As shown in Figure 14, in this modified example, unlike the embodiment of Figure 4 described above, in the XY plan view, the center of the through hole 430h of the positive terminal 430 is offset from the center of the outer flange portion 432 of the positive terminal 430. On one side of the outer flange portion 432 in the long side direction Y, a wider area Aw is secured than on the other side in the long side direction Y for connecting external connecting members such as busbars.

[0106] In this modified example, the cylindrical portion 431 of the positive electrode terminal 430 has a chamfered portion 431c at the corner on the through hole 430h side (the portion that can first come into contact with the positive electrode current collector 450). This can improve the ease of insertion when inserting the positive electrode current collector 450 into the through hole 430h. The chamfered portion 431c is formed continuously in the circumferential direction of the through hole 430h. The shape of the chamfered portion 431c is not particularly limited, but for example, it can be a chamfered shape with the corner cut off at a predetermined angle (e.g., 45 degrees), or a rounded shape with the corner rounded.

[0107] Furthermore, in this modified example, unlike the embodiment shown in Figure 4 above, the columnar second connecting portion 452 of the positive electrode current collector member 450 protrudes significantly outward from the through hole 430h of the positive electrode terminal 430. Therefore, in this modified example, the joint portion J4 is formed on the outside of the case body 12, in the middle of the columnar second connecting portion 452. The second connecting portion 452 has a protruding portion 452p at its tip (the end opposite to the first connecting portion 451). This allows the second connecting portion 452 to be brought into suitable contact with the outer flange portion 432 of the positive electrode terminal 430 by pulling the protruding portion 452p during the joining process (step 3). The length of the protruding portion 452p protruding from the through hole 430h is preferably 1 mm or more (for example, 1 to 10 mm), and more preferably 3 to 5 mm, so that it is easy to grip.

[0108] The protruding portion 452p is provided with a notch 452n (including a constriction, recess, etc.) to facilitate pulling during the joining process. The notch 452n is located on the tip side of the joining portion J4 (the part away from the first connecting portion 451). The tip of the protruding portion 452p has a rounded corner shape. This improves the ease of insertion when inserting the second connecting portion 452 into the through hole 430h. It also prevents the protruding portion 452p from interfering with other members and being damaged or broken. The R shape is preferably R = 0.1 to 0.5 when the diameter of the columnar second connecting portion 452 is 1.

[0109] (4) Terminal installation: For example, in the embodiment shown in Figure 6 above, in the (Step 1A) case preparation step, the terminals (positive terminal 30 and / or negative terminal 40) were pre-attached to the bottom wall 12a of the case body 12. That is, the case body 12 was prepared as a single molded product integrated with the gasket 90 and the terminals (positive terminal 30 and / or negative terminal 40). However, it is not limited to this. The terminals can also be attached to the bottom wall 12a in the (Step 3) joining step, for example. In one example, first, in the (Step 2) insertion step, the terminal exit holes 18 and 19 of the bottom wall 12a are sandwiched between the terminals (positive terminal 30 and / or negative terminal 40) and the conductive members (positive current collector 50 and / or negative current collector 60) from the inside and outside of the case body 12, and at least a part of the conductive members is inserted into the terminal through holes 30h and 40h. Then, in the (Step 3) joining step, the terminals and the conductive members are joined (for example, by welding). This allows the terminals to be attached to the bottom wall 12a (via insulating material, if necessary) almost simultaneously with the formation of the joint J.

[0110] As described above, specific embodiments of the technology disclosed herein include those described in the following sections. Item 1: 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 conductive member, 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 having a through hole, and the first conductive member being inserted into the through hole and joined to the first electrode terminal. Item 2: The energy storage device according to Item 1, wherein the first electrode has a first electrode tab, a first current collector as the first conductive member is attached to the first electrode tab, and the first current collector is inserted into the through hole of the first electrode terminal and joined to the first electrode terminal. Item 3: The energy storage device according to Item 1, wherein the first electrode has a group of first electrode tabs comprising a plurality of first electrode tabs, the group of first electrode tabs is inserted into the through hole of the first electrode terminal, and the group of first electrode tabs, or a conductive member connected to the group of first electrode tabs, is joined to the first electrode terminal. Item 4: The energy storage device according to any one of items 1 to 3, wherein the first electrode terminal has a recess on the side furthest from the bottom wall, and the joint between the first conductive member and the first electrode terminal is provided within the recess. Item 5: The energy storage device according to any one of items 1 to 4, further comprising a cover member that covers the joint between the first conductive member and the first electrode terminal. Item 6: The energy storage device according to any one of items 1 to 5, further comprising a spacer disposed between the bottom wall and the electrode body. Item 7: 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 conductive member, wherein the case comprises a bottomed cylindrical case body having a bottom wall, side walls 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 has a through hole A method for manufacturing an energy storage device, comprising: a case preparation step of preparing the case body and the sealing plate; an insertion step of inserting the electrode body to which the first conductive member is attached into the case body after the case preparation step and inserting at least a portion of the first conductive member into the through hole of the first electrode terminal; and a joining step of joining the first conductive member and the first electrode terminal after the insertion step. Item 8: The manufacturing method according to Item 7, wherein the first electrode has a first electrode tab, and a first current collector as the first conductive member is attached to the first electrode tab, and in the insertion step, the first current collector is inserted into the through hole of the first electrode terminal, and in the joining step, the first current collector and the first electrode terminal are joined together. Item 9: The first electrode has a first electrode tab group including a plurality of first electrode tabs. In the insertion step, the first electrode tab group is inserted into the through hole of the first electrode terminal. In the bonding step, the first electrode tab group, or a conductive member connected to the first electrode tab group, and the first electrode terminal are bonded together. The manufacturing method according to item 7. Item 10: The first electrode terminal has a recess on a surface on the side far from the bottom wall. In the bonding step, the first conductive member and the first electrode terminal are bonded together within the recess. The manufacturing method according to any one of items 7 to 9. Item 11: After the bonding step, the manufacturing method according to any one of items 7 to 10 further includes a cover attachment step of covering the bonding portion between the first conductive member and the first electrode terminal with a cover member. Item 12: The power storage device further includes a spacer disposed between the bottom wall and the electrode body. In the insertion step, after integrating the electrode body to which the first conductive member is attached with the spacer, the electrode body in a state integrated with the spacer is inserted into the case body. The manufacturing method according to any one of items 7 to 11. Item 13: After the insertion step, the first conductive member is deformed. In the bonding step, the deformed first conductive member is brought into contact with the first electrode terminal and bonded to the first electrode terminal. The manufacturing method according to any one of items 7 to 12.

Description of reference numerals

[0111] 10 Case 12 Case body 12a Bottom wall 14 Sealing plate 20, 120, 220, 320 Electrode body 22 Positive electrode (first electrode / second electrode) 24 Negative electrode (first electrode / second electrode) 27, 127, 227 Positive electrode tab group (first conductive member) 30, 130, 230, 330, 430 Positive electrode terminal (first electrode terminal) 30h, 130h, 230h, 330h, 430h Through hole 40 Negative electrode terminal 50, 150, 250, 450 Positive electrode current collector (first conductive member) 60 Negative electrode current collector 80, 180, 280, 380 spacers 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 conductive member, 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 and has a through hole. The first conductive member is inserted into the through hole and joined to the first electrode terminal in the energy storage device.

2. The first electrode has a first electrode tab, A first current collector, which is the first conductive member, is attached to the first electrode tab. The first current collector is inserted into the through hole of the first electrode terminal and joined to the first electrode terminal. The energy storage device according to claim 1.

3. The first electrode has a group of first electrode tabs, which includes a plurality of first electrode tabs. The first electrode tab group is inserted into the through hole of the first electrode terminal, The first electrode tab group, or a conductive member connected to the first electrode tab group, is joined to the first electrode terminal. The energy storage device according to claim 1.

4. The first electrode terminal has a recess on the side furthest from the bottom wall, The joint between the first conductive member and the first electrode terminal is provided within the recess. The energy storage device according to any one of claims 1 to 3.

5. The system further comprises a cover member that covers the joint between the first conductive member and the first electrode terminal. The energy storage device according to any one of claims 1 to 3.

6. The system further comprises a spacer disposed between the bottom wall and the electrode body. The energy storage device according to any one of claims 1 to 3.

7. 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 conductive member, 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 and has a through hole. The first conductive member is inserted into the through hole and joined to the first electrode terminal. A case preparation step involves preparing the case body and the sealing plate, After the case preparation step, the electrode body to which the first conductive member is attached is inserted into the case body, and at least a portion of the first conductive member is inserted into the through hole of the first electrode terminal in an insertion step, After the insertion step, a bonding step is performed to join the first conductive member and the first electrode terminal, A method for manufacturing an energy storage device, including the method described above.

8. The first electrode has a first electrode tab, A first current collector, which serves as the first conductive member, is attached to the first electrode tab. In the insertion step, the first current collector is inserted into the through hole of the first electrode terminal. In the joining process, the first current collector and the first electrode terminal are joined together. The manufacturing method according to claim 7.

9. The first electrode has a group of first electrode tabs, which includes a plurality of first electrode tabs. In the insertion step, the first electrode tab group is inserted into the through hole of the first electrode terminal. In the bonding step, the first electrode tab group, or a conductive member connected to the first electrode tab group, is bonded to the first electrode terminal. The manufacturing method according to claim 7.

10. The first electrode terminal has a recess on the side furthest from the bottom wall, In the bonding process, the first conductive member and the first electrode terminal are bonded within the recess. The manufacturing method according to any one of claims 7 to 9.

11. The process further includes a cover attachment step in which the joint between the first conductive member and the first electrode terminal is covered with a cover member after the bonding step, The manufacturing method according to any one of claims 7 to 9.

12. The energy storage device further comprises a spacer disposed between the bottom wall and the electrode body, In the insertion step, After integrating the electrode body to which the first conductive member is attached with the spacer, The electrode body, integrated with the spacer, is inserted into the case body. The manufacturing method according to any one of claims 7 to 9.

13. After the insertion step, the first conductive member is deformed, In the bonding process, the deformed first conductive member is brought into contact with the first electrode terminal and bonded to the first electrode terminal. The manufacturing method according to any one of claims 7 to 9.

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