Secondary batteries

Abstract

To improve the energy density of secondary batteries and to manufacture them stably. [Solution] In this secondary battery, an insulating sheet 700 and a spacer 600 (first spacer) are connected, and an insulating sheet 700 and a spacer 600 (second spacer) are connected. The case 100 includes a case body 110 having a first opening 113 at one end and a second opening 114 at the other end, a first sealing plate 120 that seals the first opening 113 and is welded to the case body 110, and a second sealing plate 130 that seals the second opening 114 and is welded to the case body 110. The first electrode tab 220 is located at the end of the electrode body 200 on the side of the first sealing plate 120, and the second electrode tab 250 is located at the end of the electrode body 200 on the side of the second sealing plate 130. The insulating sheet 700 has overlapping portions where the insulating sheets 700 overlap each other, and in the overlapping portions, there is a region facing the electrode body 200 where no joint is formed between the insulating sheets 700.

Description

Technical Field

[0001] This technology relates to secondary batteries.

Background Art

[0002] Japanese Patent No. 4537353 (Patent Document 1) discloses a rectangular secondary battery in which an electrode group (25) is housed in a case (14) having openings (14a, 14b) at both ends, and electrode terminals (21, 23) are attached to cap plates (33, 33') that seal the openings (14a, 14b).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the secondary battery described in Patent Document 1, there is room to improve the energy density and stably manufacture the secondary battery.

[0005] This technology has been made to solve the above problems, and an object thereof is to provide a secondary battery that can improve the energy density and be stably manufactured.

Means for Solving the Problems

[0006] This technology provides the following secondary battery. [1] An electrode body comprising a first electrode and a second electrode having a different polarity from the first electrode; a case for housing the electrode body; a first electrode tab electrically connected to the first electrode and located at one end of the electrode body; a second electrode tab electrically connected to the second electrode and located at the other end of the electrode body; a first spacer located opposite the first electrode tab; a second spacer located opposite the second electrode tab; and an insulating sheet located to cover the electrode body, the first spacer and the second spacer, wherein the insulating sheet and the first spacer are connected, and the insulating sheet and the A secondary battery comprising a case body having a first opening at one end and a second opening at the other end, a first sealing plate welded to the case body and sealing the first opening, and a second sealing plate welded to the case body and sealing the second opening, wherein the first electrode tab is positioned at the end of the electrode body on the first sealing plate side, the second electrode tab is positioned at the end of the electrode body on the second sealing plate side, and the insulating sheet has an overlapping portion where the insulating sheets overlap each other, and in the overlapping portion, there is a region facing the electrode body where no joint portion is formed between the insulating sheets.

[0007] [2] In a region where no joint is formed between the insulating sheets, there exists a gap through which gas can pass from between the insulating sheets and the electrode body to between the insulating sheets and the case, as described in [1].

[0008] [3] The secondary battery according to [1] or [2], wherein a first electrode terminal is attached to the first sealing plate, a second electrode terminal is attached to the second sealing plate, the first electrode tab is electrically connected to the first electrode terminal without an electrode body other than the electrode body, and the second electrode tab is electrically connected to the second electrode terminal without an electrode body other than the electrode body. [Effects of the Invention]

[0009] This technology improves the energy density of secondary batteries and enables the stable manufacture of secondary batteries. [Brief explanation of the drawing]

[0010] [Figure 1] This is a front view showing the configuration of a secondary battery according to Embodiment 1 of this technology. [Figure 2] This figure shows the secondary battery shown in Figure 1 as viewed from the direction of arrow II. [Figure 3] This figure shows the secondary battery shown in Figure 1 as viewed from the direction of arrow III. [Figure 4] Figure 1 shows the secondary battery as viewed from the direction of arrow IV. [Figure 5] This figure shows the secondary battery shown in Figure 1 as viewed from the direction of arrow V. [Figure 6] Figure 1 is a front cross-sectional view of a secondary battery. [Figure 7] This is a front view showing the negative electrode base plate before the negative electrode plate is formed. [Figure 8] Figure 7 shows a cross-sectional view of the negative electrode plate along line VIII-VIII. [Figure 9] This is a front view showing a negative electrode plate formed from a negative electrode base plate. [Figure 10] This is a front view showing the positive electrode raw material before the positive electrode plate is formed. [Figure 11] Figure 10 is a cross-sectional view of the positive electrode plate along line XI-XI. [Figure 12] This is a front view showing a positive electrode plate formed from a positive electrode base plate. [Figure 13] Figure 1 is a cross-sectional view of the secondary battery shown along line XIII-XIII. [Figure 14] Figure 1 is a cross-sectional view of the secondary battery along line XIV-XIV. [Figure 15] This is a first perspective view showing the overall configuration of the spacer. [Figure 16] This is a second perspective view showing the overall configuration of the spacer. [Figure 17] This is a flowchart showing the method for manufacturing a secondary battery according to Embodiment 1. [Figure 18] It is a perspective view showing a state before two electrode bodies included in the secondary battery according to Embodiment 1 overlap. [Figure 19] It is a XIX-XIX cross-sectional view of the electrode body and the current collector shown in FIG. 18. [Figure 20] It is a perspective view showing a state in which an insulating sheet and a spacer are attached to the electrode body. [Figure 21] It is a view showing a state where the insulating sheet is unfolded. [Figure 22] It is a view showing a state where another insulating sheet is unfolded. [Figure 23] It is a XXIII-XXIII cross-sectional view shown in FIG. 20. [Figure 24] It is a perspective view showing a state in which a holder and a spacer are attached to the electrode body. [Figure 25] It is a perspective view showing a state in which a first sealing plate is attached to the first current collector. [Figure 26] It is a XXVI-XXVI cross-sectional view of the electrode body and the current collector shown in FIG. 25. [Figure 27] It is a perspective view showing a state in which the electrode body is inserted into the case body. [Figure 28] It is a perspective view showing a state in which a second sealing plate is attached to the second current collector. [Figure 29] It is a XXIX-XXIX cross-sectional view of the electrode body and the current collector shown in FIG. 28. [Figure 30] It is a perspective view showing the configuration of the secondary battery according to Embodiment 1. [Figure 31] It is a cross-sectional view corresponding to the XXVI-XXVI cross-section of the electrode body and the current collector shown in FIG. 25 of the secondary battery according to Embodiment 2. [Figure 32] It is a cross-sectional view showing a state where the electrode tab is bent. [Figure 33] It is a first perspective view showing the overall configuration of the spacer according to Embodiment 2. [Figure 34] It is a second perspective view showing the overall configuration of the spacer according to Embodiment 2. [Figure 35]This is a perspective view showing the overall configuration of the spacer according to Embodiment 3. [Figure 36] This is a cross-sectional view corresponding to line XIII-XIII in Figure 1, relating to Embodiment 4. [Figure 37] This is a first perspective view showing the overall configuration of the spacer according to Embodiment 4. [Figure 38] This is a second perspective view showing the overall configuration of the spacer according to Embodiment 4. [Modes for carrying out the invention]

[0011] Embodiments of this technology are described below. Note that the same or corresponding parts may be denoted by the same reference numerals, and their descriptions may not be repeated.

[0012] In the embodiments described below, when referring to the number, quantity, etc., unless otherwise specified, the scope of this technology is not necessarily limited to that number, quantity, etc. Also, in the embodiments described below, each component is not necessarily essential to this technology unless otherwise specified. Furthermore, this technology is not necessarily limited to achieving all of the effects and advantages mentioned in these embodiments.

[0013] In this specification, the terms "comprise," "include," and "have" are in open-ended form. That is, if a configuration includes one configuration, it may also include other configurations, or it may not.

[0014] Furthermore, where geometric terms and terms describing positional and directional relationships are used in this specification, such as "parallel," "orthogonal," "45° oblique," "coaxial," and "alongside," these terms allow for manufacturing tolerances or slight variations. Where terms describing relative positional relationships, such as "upper" and "lower," are used in this specification, these terms are used to indicate the relative positional relationship in a single state, and the relative positional relationship may be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, by inverting the entire mechanism upside down).

[0015] In this specification, “secondary battery” is not limited to lithium-ion batteries, but may include other secondary batteries such as nickel-metal hydride batteries and sodium-ion batteries. In this specification, “electrode” may refer collectively to the positive electrode and the negative electrode.

[0016] In the drawings, the direction along the winding axis of the electrode body of the secondary battery is defined as the X direction, the short side of the electrode body as viewed from the X direction is defined as the Y direction, and the long side of the electrode body as viewed from the X direction is defined as the Z direction. Furthermore, in order to facilitate understanding of the invention, the dimensions of each component in the drawings have been altered from the actual dimensions in some cases.

[0017] In this specification, the first direction (X direction) may be referred to as the "width direction" of the secondary battery or case body, the second direction (Y direction) may be referred to as the "thickness direction" of the secondary battery or case body, and the third direction (Z direction) may be referred to as the "height direction" of the secondary battery or case body.

[0018] (Embodiment 1) (Overall battery configuration) Figure 1 is a front view of the secondary battery 1 according to this embodiment. Figures 2 to 5 show the secondary battery 1 shown in Figure 1 as viewed from the directions of arrows II, III, IV, and V, respectively. Figure 6 is a front cross-sectional view of the secondary battery 1 shown in Figure 1. Note that the spacer 600, which will be described later, is not shown in the cross-sectional view shown in Figure 6 for the sake of explanation.

[0019] The secondary battery 1 can be installed in electric vehicles (BEVs), plug-in hybrid electric vehicles (PHEVs), and hybrid electric vehicles (HEVs), etc. However, the use of the secondary battery 1 is not limited to automotive applications.

[0020] As shown in Figures 1 to 6, the secondary battery 1 includes a case 100, an electrode body 200, electrode terminals 300, and a current collector 400. The case 100 includes a case body 110, a first sealing plate 120, and a second sealing plate 130.

[0021] When a battery pack including a secondary battery 1 is constructed, multiple secondary batteries 1 are stacked in the thickness direction. The stacked secondary batteries 1 may be constrained in the stacking direction (Y direction) by a restraining member to form a battery module, or the battery pack may be directly supported on the side of the battery pack case without using a restraining member.

[0022] The case body 110 consists of a cylindrical, preferably rectangular, member. This results in a rectangular secondary battery 1. The case body 110 is made of metal. Specifically, the case body 110 is made of aluminum, aluminum alloy, iron, or iron alloy.

[0023] As shown in Figures 1 and 2, a first sealing plate 120 and a second sealing plate 130 are provided at both ends of the case body, respectively. The case body 110 can be formed into a rectangular tube shape by, for example, bringing together the ends of bent plate-like members (joint portion 115 as illustrated in Figure 2) and joining them together (for example, by laser welding). The corners of the "rectangular tube" may have a rounded shape.

[0024] In this embodiment, the case body 110 is formed to be longer in the width direction (X direction) of the secondary battery 1 than in the thickness direction (Y direction) and height direction (Z direction) of the secondary battery 1. The dimension (width) of the case body 110 in the X direction is preferably about 30 cm or more. This makes it possible to construct a relatively large (high capacity) secondary battery 1. The dimension (height) of the case body 110 in the Z direction is preferably about 20 cm or less, more preferably about 15 cm or less, and even more preferably about 10 cm or less. This makes it possible to construct a relatively low-height secondary battery 1, which improves, for example, its mountability in a vehicle.

[0025] The case body 110 includes a pair of first side sections 111 and a pair of second side sections 112. The pair of first side sections 111 constitute a part of the side surface of the case 100. The pair of second side sections 112 constitute the bottom and top surfaces of the case 100. Each of the pair of first side sections 111 and the pair of second side sections 112 is provided so as to intersect each other. The pair of first side sections 111 and the pair of second side sections 112 are connected at their respective ends. It is desirable that each of the pair of first side sections 111 has a larger area than each of the pair of second side sections 112.

[0026] As shown in Figure 5, a gas exhaust valve 150 is provided on one of the pair of second side portions 112A. The gas exhaust valve 150 extends in the width direction (X direction) of the secondary battery 1. The gas exhaust valve 150 extends in the X direction to the extent that it does not reach the ends of the case body 110 from the center in the X direction. The gas exhaust valve 150 can be modified as appropriate.

[0027] The thickness of the plate-shaped member in the gas discharge valve 150 is thinner than the thickness of the other plate-shaped members in the case body 110. As a result, when the pressure inside the case 100 exceeds a predetermined value, the gas discharge valve 150 preferentially ruptures compared to other parts of the case body 110, and discharges the gas inside the case 100 to the outside.

[0028] As shown in Figure 2, a joint portion 115 is formed on the other second side portion 112B of the pair of second side portions 112. The joint portion 115 extends in the width direction (X direction) of the secondary battery 1. At the joint portion 115, the ends of the plate-shaped members constituting the case body 110 are joined together.

[0029] As shown in Figure 3, a first opening 113 is provided at the first side end of the case body 110 in the first direction (X direction). The first opening 113 is sealed by a first sealing plate 120. A joint 115 is formed in the first opening 113 to seal it. The first opening 113 and the first sealing plate 120 have a substantially rectangular shape with the Y direction being the short side and the Z direction being the long side.

[0030] A negative electrode terminal 301 (first electrode terminal) is provided on the first sealing plate 120. The position of the negative electrode terminal 301 can be changed as appropriate.

[0031] As shown in Figure 4, a second opening 114 is provided at the end of the case body 110 on the second side opposite to the first side in the first direction (X direction). That is, the second opening 114 is located at the end opposite to the first opening 113. The second opening 114 is sealed by a second sealing plate 130. A joint 115 is formed in the second opening 114 to seal it. The second opening 114 and the second sealing plate 130 have a substantially rectangular shape with the Y direction being the short side and the Z direction being the long side.

[0032] A positive electrode terminal 302 (second electrode terminal) and an injection hole 134 are provided on the second sealing plate 130. The positions of the positive electrode terminal 302 and the injection hole 134 can be changed as appropriate.

[0033] The first sealing plate 120 and the second sealing plate 130 are made of metal. Specifically, the first sealing plate 120 and the second sealing plate 130 are made of aluminum, aluminum alloy, iron, or iron alloy, etc.

[0034] The negative electrode terminal 301 is electrically connected to the negative electrode (first electrode) of the electrode body 200. The negative electrode terminal 301 is attached to the first sealing plate 120, i.e., the case 100.

[0035] The positive terminal 302 is electrically connected to the positive electrode (second electrode) of the electrode body 200. The positive terminal 302 is attached to the second sealing plate 130, i.e., the case 100.

[0036] The negative electrode terminal 301 is made of a conductive material (more specifically, a metal), such as copper or a copper alloy. A portion or layer made of aluminum or an aluminum alloy may be provided on the outer surface of the negative electrode terminal 301.

[0037] The positive terminal 302 is made of a conductive material (more specifically, a metal), which may be made of aluminum or an aluminum alloy, for example.

[0038] The injection hole 134 is sealed by a sealing member (not shown). For example, a blind rivet or other metal member can be used as the sealing member.

[0039] The electrode body 200 is a flat-shaped electrode body having a positive electrode plate and a negative electrode plate, which will be described later. Specifically, the electrode body 200 is a wound-type electrode body in which a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are wound together via a strip-shaped separator (not shown). However, in this specification, "electrode body" is not limited to a wound-type electrode body, and may also be a laminated-type electrode body in which multiple positive electrode plates and multiple negative electrode plates are alternately stacked. The strip-shaped separator can be made of, for example, a polyolefin microporous film. The electrode body may include multiple positive electrode plates and multiple negative electrode plates, and positive electrode tabs provided on each positive electrode plate may be stacked to form a group of positive electrode tabs, or negative electrode tabs provided on each negative electrode plate may be stacked to form a group of negative electrode tabs. The electrode body 200 may include multiple wound-type electrode bodies, or it may include multiple laminated-type electrode bodies.

[0040] As shown in Figure 6, the case 100 houses the electrode body 200. In Figure 6, the first electrode body 201, which will be described later, is shown as an example. The first electrode body 201 is housed in the case 100 so that its winding axis is parallel to the X direction.

[0041] Specifically, one or more wound electrode bodies are housed inside the insulating sheet 700 (described later) placed within the case 100, together with an electrolyte (not shown). As the electrolyte (non-aqueous electrolyte), for example, a non-aqueous solvent prepared by mixing ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) in a volume ratio (25°C) of 30:30:40, in which LiPF6 is dissolved at a concentration of 1.2 mol / L can be used. Alternatively, a solid electrolyte may be used instead of the electrolyte.

[0042] The first electrode body 201 includes a main body (a portion in which a positive electrode plate and a negative electrode plate are stacked with a separator in between), a first electrode tab 220 (a group of negative electrode tabs), and a second electrode tab 250 (a group of positive electrode tabs).

[0043] The main body is composed of a negative electrode plate 210 and a positive electrode plate 240, which will be described later. The first electrode tab 220 is located at the first side end of the first electrode body 201 in a first direction (X direction) relative to the main body. In this embodiment, the first side is the side of the first sealing plate 120. The second electrode tab 250 is located at the second side end of the first electrode body 201 in a first direction (X direction) relative to the main body. In this embodiment, the second side is the side of the second sealing plate 130.

[0044] The first electrode tab 220 and the second electrode tab 250 are formed to protrude from the central portion of the electrode body 200 toward the first sealing plate 120 or the second sealing plate 130, respectively.

[0045] The current collector 400 includes a negative electrode current collector 400A and a positive electrode current collector 400B. The negative electrode current collector 400A and the positive electrode current collector 400B are each made of plate-shaped members. The electrode body 200 is electrically connected to the negative electrode terminal 301 and the positive electrode terminal 302 via the current collector 400.

[0046] The negative electrode current collector 400A is positioned on the first sealing plate 120 via a resin insulating member. The negative electrode current collector 400A is electrically connected to the first electrode tab 220 and the negative electrode terminal 301. The negative electrode current collector 400A is made of a conductive material (more specifically, a metal), such as copper or a copper alloy. Further details of the negative electrode current collector 400A will be described later.

[0047] The positive electrode current collector 400B is positioned on the second sealing plate 130 via a resin insulating member. The positive electrode current collector 400B is electrically connected to the second electrode tab 250 and the positive electrode terminal 302. The positive electrode current collector 400B is made of a conductive material (more specifically, a metal), such as aluminum or an aluminum alloy. The second electrode tab 250 may be electrically connected to the second sealing plate 130 directly or via the positive electrode current collector 400B. In this case, the second sealing plate 130 may also function as the positive electrode terminal 302. Further details of the positive electrode current collector 400B will be described later.

[0048] (Configuration of electrode body 200) Figure 7 is a front view showing the negative electrode base plate 210S before the negative electrode plate 210 (first electrode) is formed, Figure 8 is a cross-sectional view of the negative electrode base plate 210S shown in Figure 7, and Figure 9 is a front view showing the negative electrode plate 210 formed from the negative electrode base plate 210S.

[0049] The negative electrode plate 210 is manufactured by processing the negative electrode base plate 210S. As shown in Figures 7 and 8, the negative electrode base plate 210S includes a negative electrode core 211 and a negative electrode active material layer 212. The negative electrode core 211 is copper foil or copper alloy foil.

[0050] The negative electrode core body 211 has a negative electrode active material layer 212 formed on both sides, except for one end. The negative electrode active material layer 212 is formed by applying a negative electrode active material slurry using a die coater.

[0051] The negative electrode active material layer slurry is prepared by kneading graphite as the negative electrode active material, styrene-butadiene rubber (SBR) and carboxymethylcellulose (CMC) as binders, and water as a dispersion medium, so that the mass ratio of graphite:SBR:CMC is approximately 98:1:1.

[0052] The negative electrode core 211, to which the negative electrode active material layer slurry has been applied, is dried to remove water contained in the negative electrode active material layer slurry, thereby forming the negative electrode active material layer 212. Furthermore, by compressing the negative electrode active material layer 212, a negative electrode base plate 210S containing the negative electrode core 211 and the negative electrode active material layer 212 is formed. The negative electrode plate 210 is formed by cutting the negative electrode base plate 210S into a predetermined shape. The negative electrode base plate 210S can be cut by laser processing using energy beam irradiation, mold processing, or cutter processing.

[0053] As shown in Figure 9, a plurality of negative electrode tabs 230, each made of a negative electrode core 211, are provided at one end in the width direction of the negative electrode plate 210 formed from the negative electrode base plate 210S. When the negative electrode plate 210 is wound, the plurality of negative electrode tabs 230 are stacked to form the first electrode tab 220. As a result, the first electrode tab 220 is connected to the negative electrode plate 210 (first electrode). The position and protruding length of each of the plurality of negative electrode tabs 230 are appropriately adjusted considering the state in which the first electrode tab 220 is connected to the negative electrode current collector 400A. Note that the shape of the negative electrode tab 230 is not limited to that illustrated in Figure 8.

[0054] Figure 10 is a front view showing the positive electrode base plate 240S before the positive electrode plate 240 (second electrode) is formed, Figure 11 is a cross-sectional view of the positive electrode base plate 240S shown in Figure 10 from line XI, and Figure 12 is a front view showing the positive electrode plate 240 formed from the positive electrode base plate 240S.

[0055] The positive electrode plate 240, which is the second electrode, has a different polarity from the negative electrode plate 210, which is the first electrode. The positive electrode plate 240 is manufactured by processing a positive electrode base plate 240S. As shown in Figures 10 and 11, the positive electrode base plate 240S includes a positive electrode core 241, a positive electrode active material layer 242, and a positive electrode protective layer 243. The positive electrode core 241 is aluminum foil or aluminum alloy foil.

[0056] A positive electrode active material layer 242 is formed on the positive electrode core 241, except for one end on both sides. The positive electrode active material layer 242 is formed on the positive electrode core 241 by applying a positive electrode active material slurry using a die coater.

[0057] The positive electrode active material layer slurry is prepared by kneading lithium nickel cobalt manganese composite oxide as the positive electrode active material, polyvinylidene fluoride (PVdF) as a binder, carbon material as a conductive material, and N-methyl-2-pyrrolidone (NMP) as a dispersion medium, such that the mass ratio of lithium nickel cobalt manganese composite oxide:PVdF:carbon material is approximately 97.5:1:1.5.

[0058] The positive electrode protective layer 243 is in contact with the positive electrode core 241 and is formed on one end of the positive electrode active material layer 242 in the width direction. The positive electrode protective layer 243 is formed on the positive electrode core 241 by applying a positive electrode protective layer slurry with a die coater. The positive electrode protective layer 243 has an electrical resistance greater than that of the positive electrode active material layer 242.

[0059] The positive electrode protective layer slurry is prepared by kneading alumina powder, carbon material as a conductive material, PVdF as a binder, and NMP as a dispersion medium, such that the mass ratio of alumina powder:carbon material:PVdF is approximately 83:3:14.

[0060] The positive electrode core 241, to which the positive electrode active material layer slurry and positive electrode protective layer slurry have been applied, is dried to remove NMP contained in the positive electrode active material layer slurry and positive electrode protective layer slurry, thereby forming the positive electrode active material layer 242 and positive electrode protective layer 243. Furthermore, by compressing the positive electrode active material layer 242, a positive electrode base plate 240S containing the positive electrode core 241, positive electrode active material layer 242, and positive electrode protective layer 243 is formed. The positive electrode plate 240 is formed by cutting the positive electrode base plate 240S into a predetermined shape. The positive electrode base plate 240S can be cut by laser processing using energy beam irradiation, mold processing, or cutter processing.

[0061] As shown in Figure 12, a plurality of positive electrode tabs 260, each made of a positive electrode core 241, are provided at one end in the width direction of the positive electrode plate 240 formed from the positive electrode base plate 240S. When the positive electrode plate 240 is wound, the plurality of positive electrode tabs 260 are stacked to form a second electrode tab 250. As a result, the second electrode tab 250 is connected to the positive electrode plate 240 (second electrode). The position and protruding length of each of the plurality of positive electrode tabs 260 are appropriately adjusted considering the state in which the second electrode tab 250 is connected to the positive electrode current collector 400B. Note that the shape of the positive electrode tab 260 is not limited to that exemplified in Figure 12.

[0062] A positive electrode protective layer 243 is provided at the base of each of the multiple positive electrode tabs 260. However, a positive electrode protective layer 243 is not necessarily provided at the base of each positive electrode tab 260.

[0063] In a typical example, the thickness of the negative electrode tab 230 (one piece) is less than the thickness of the positive electrode tab 260 (one piece). In this case, the thickness of the first electrode tab 220 is less than the thickness of the second electrode tab 250.

[0064] (Connection structure between electrode body 200 and current collector 400) Figure 13 is a cross-sectional view of the secondary battery shown in Figure 1 along line XIII-XIII. As shown in Figure 13, the electrode body 200 includes a first electrode body 201 and a second electrode body 202. Each of the first electrode body 201 and the second electrode body 202 includes a first electrode (negative electrode) and a second electrode (positive electrode). The electrode body 200 may be composed of three or more electrode bodies.

[0065] The electrode body 200 is formed by stacking a first electrode body 201 and a second electrode body 202. The first electrode body 201 and the second electrode body 202 are aligned in the thickness direction (Y direction) of the first electrode body 201 and the second electrode body 202.

[0066] The first electrode body 201 includes a first electrode tab 220. The first electrode tab 220 is electrically connected to the first electrode at a first end 205 in the X direction. The second electrode body 202 includes a third electrode tab 270. The third electrode tab 270 is electrically connected to the first electrode at a third end 207 in the X direction.

[0067] The first electrode tab 220 has a curved portion 221 (first curved portion) and a tip portion 222. The curved portion 221 (first curved portion) is the part of the first electrode tab 220 that is curved relative to the tip portion 222 on the side to which the first electrode is connected. The first electrode tab 220 includes a recess 221a (first recess) in which the region opposite to the convex portion 616 (first convex portion) provided on the spacer 600, which will be described in detail later, is recessed. The tip portion 222 is the part of the first electrode tab 220 located at the end opposite to the side to which the first electrode is connected.

[0068] The third electrode tab 270 has a curved portion 271 (third curved portion) and a tip portion 272. The curved portion 271 (third curved portion) is the part of the third electrode tab 270 that is curved relative to the tip portion 272 on the side to which the first electrode is connected. The third electrode tab 270 includes a recess 271a (third recess) in which the region opposite to the convex portion 626 (second convex portion) provided on the spacer 600, which will be described in detail later, is recessed. The tip portion 272 is the part of the third electrode tab 270 located at the end opposite to the side to which the first electrode is connected.

[0069] The first electrode tab 220 and the third electrode tab 270 are each curved in opposite directions so that their tips 222 and 272 are closer together. In this embodiment, the tips 222 and 272 are spaced apart, but the configuration is not limited to this, and the tips 222 and 272 may be in contact with each other.

[0070] The negative electrode current collector 400A electrically connects the negative electrode terminal 301 to the first electrode tab 220 and the third electrode tab 270. In this embodiment, the negative electrode current collector 400A is connected to the negative electrode terminal 301 between the electrode body 200 and the first sealing plate 120.

[0071] The negative electrode current collector 400A includes a first current collector 410, a third current collector 430, and a first electrode terminal side current collector 440.

[0072] The first current collector 410 is a plate-shaped member. The first current collector 410 has a longitudinal direction in the Z direction and a short direction in the Y direction. The third current collector 430 is a plate-shaped member. The third current collector 430 has a longitudinal direction in the Z direction and a short direction in the Y direction. The first current collector 410 and the third current collector 430 are arranged in parallel in the X direction. Thus, the first current collector 410 and the third current collector 430 are composed of separate parts.

[0073] The first electrode tab 220 is joined to the first current collector 410 at a joining point 411, which will be described later. The third electrode tab 270 is joined to the third current collector 430 at a joining point 431, which will be described later. The joining points 411 and 431 can be formed by, for example, ultrasonic welding, resistance welding, laser welding, crimping, etc. In this embodiment, the first electrode tab 220 and the first current collector 410, and the third electrode tab 270 and the third current collector 430 are joined by, for example, ultrasonic welding.

[0074] The first electrode terminal-side current collector 440 is joined to the first current collector 410 and the third current collector 430 at a joint (not shown) located at its Z-direction end. The first electrode terminal-side current collector 440 is connected to the negative electrode terminal 301. The connection between the first electrode terminal-side current collector 440 and the negative electrode terminal 301 can be formed, for example, by crimping and / or welding.

[0075] The negative electrode terminal 301 is exposed on the outside of the first sealing plate 120 and is positioned to reach the first electrode terminal side current collector 440 of the negative electrode current collector 400A, which is provided on the inner surface side of the first sealing plate 120. The negative electrode terminal 301 is connected to the first plate portion 303.

[0076] The first plate portion 303 is located on the outside of the first sealing plate 120. The first plate portion 303 is arranged along the first sealing plate 120. The first plate portion 303 is conductive. The first plate portion 303 is arranged to secure connection area with busbars, etc., that electrically connect the secondary battery 1 to other adjacent secondary batteries. The connection between the negative electrode terminal 301 and the first plate portion 303 can be formed, for example, by laser welding.

[0077] A first insulating member 510 is placed between the first plate portion 303 and the first sealing plate 120. A second insulating member 520 is placed between the negative electrode terminal 301 and the first sealing plate 120. A third insulating member 530 is placed between the first electrode terminal side current collector 440 and the first sealing plate 120.

[0078] However, the negative terminal 301 may be electrically connected to the first sealing plate 120. Alternatively, the first sealing plate 120 may also function as the negative terminal 301.

[0079] A spacer 600 (first spacer) is positioned between the first sealing plate 120 and the electrode body 200. This spacer 600 suppresses large movements of the electrode body 200 within the case 100. The spacer 600 is made of an insulating resin material. The spacer 600 includes a first component 610 and a second component 620. The first component 610 and the second component 620 are engaged with each other at engaging portions (not shown) at both ends in the Z direction.

[0080] The first component 610 has a protrusion 616 (first protrusion) on the end side facing the electrode body 200 in the X direction, which protrudes toward the second component 620 in the Y direction. The second component 620 has a protrusion 626 (second protrusion) on the end side facing the electrode body 200 in the X direction, which protrudes toward the first component 610 in the Y direction. By providing the protrusions 616 (first protrusion) and 626 (second protrusion), the spacer 600 acts as a guide to facilitate the curvature of the curved portion 221 (first curvature) and the curved portion 271 (third curvature) when they are curved. The detailed structure of the spacer 600 will be described later.

[0081] A resin insulating sheet 700 is placed between the electrode body 200 and the case body 110. More specifically, the insulating sheet 700 covers the electrode body 200 and also surrounds the side wall of the spacer 600 on the case body 110 side, so the spacer 600 is covered by the insulating sheet 700. Furthermore, the insulating sheet 700 is connected to the spacer 600 by a method described later.

[0082] The insulating sheet 700 may be made of, for example, a resin. More specifically, the material of the insulating sheet 700 may be, for example, polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyimide (PI), or polyolefin (PO).

[0083] Furthermore, the third insulating member 530 is positioned between the spacer 600 (first spacer) and the first sealing plate 120. Alternatively, the spacer 600 may be placed in contact with the third insulating member 530, or with the first sealing plate 120.

[0084] Figure 14 is a cross-sectional view of the secondary battery shown in Figure 1, taken along the line XIV-XIV. In this embodiment, the connection structure between the electrode body 200 and the current collector 400 on the second electrode (positive electrode) side of the secondary battery 1 differs from the configuration on the first electrode (negative electrode) side in that the parts corresponding to the first current collector 410 and the third current collector 430 on the first electrode (negative electrode) side are made up of a single component.

[0085] The first electrode body 201 includes a second electrode tab 250. The second electrode tab 250 is electrically connected to the second electrode at a second end 206 in the X direction. The second electrode body 202 includes a fourth electrode tab 280. The fourth electrode tab 280 is electrically connected to the second electrode at a fourth end 208 in the X direction.

[0086] The second electrode tab 250 has a curved portion 251 (second curved portion) and a tip portion 252. The curved portion 251 (second curved portion) is the part of the second electrode tab 250 that is curved relative to the tip portion 252 on the side to which the second electrode is connected. The second electrode tab 250 includes a recess 251a (second recess) in which the region opposite to the convex portion 616 (second convex portion) provided on the spacer 600 (second spacer), which will be described in detail later, is recessed. The tip portion 252 is the part of the second electrode tab 250 located at the end opposite to the side to which the second electrode is connected.

[0087] The fourth electrode tab 280 has a curved portion 281 (fourth curved portion) and a tip portion 282. The curved portion 281 (fourth curved portion) is the part of the fourth electrode tab 280 that is curved relative to the tip portion 282 on the side to which the second electrode is connected. The fourth electrode tab 280 includes a recess 281a (fourth recess) in which the region opposite to the convex portion 626 (fourth convex portion) provided on the spacer 600, which will be described in detail later, is recessed. The tip portion 282 is the part of the fourth electrode tab 280 located at the end opposite to the side to which the second electrode is connected.

[0088] The second electrode tab 250 and the fourth electrode tab 280 are each curved in opposite directions so that their tips 252 and 282 are closer together. In this embodiment, the tips 252 and 272 are spaced apart, but the configuration is not limited to this, and the tips 252 and 282 may be in contact with each other.

[0089] The positive electrode current collector 400B electrically connects the positive electrode terminal 302 to the second electrode tab 250 and the fourth electrode tab 280. In this embodiment, the positive electrode current collector 400B is connected to the positive electrode terminal 302 between the electrode body 200 and the second sealing plate 130.

[0090] The positive electrode current collector 400B includes a second current collector 420 and a second electrode terminal side current collector 450.

[0091] The second current collector 420 is a plate-shaped member. The second current collector 420 has a longitudinal direction in the Z direction and a short direction in the Y direction. The second current collector 420 is composed of a single, integrated part.

[0092] The second electrode tab 250 and the fourth electrode tab 280 are joined to the second current collector 420, which is made up of a single component, at a joint 421 described later. The joint 421 can be formed by, for example, ultrasonic welding, resistance welding, laser welding, crimping, etc. In this embodiment, the second electrode tab 250 and the fourth electrode tab 280 and the second current collector 420 are joined by, for example, ultrasonic bonding.

[0093] The second electrode terminal-side current collector 450 is joined to the second current collector 420 at a joint (not shown) located at its Z-direction end. The second electrode terminal-side current collector 450 is connected to the positive electrode terminal 302. The connection between the second electrode terminal-side current collector 450 and the positive electrode terminal 302 can be formed, for example, by crimping and / or welding.

[0094] The positive terminal 302 is exposed on the outside of the second sealing plate 130 and is positioned to reach the second electrode terminal side current collector 450 of the positive current collector 400B, which is provided on the inner surface side of the second sealing plate 130. The positive terminal 302 is connected to the second plate portion 304.

[0095] The second plate portion 304 is located on the outside of the second sealing plate 130. The second plate portion 304 is arranged along the second sealing plate 130. The second plate portion 304 is conductive. The second plate portion 304 is arranged to secure connection area with busbars, etc., that electrically connect the secondary battery 1 to other adjacent secondary batteries. The connection between the positive electrode terminal 302 and the second plate portion 304 can be formed, for example, by laser welding.

[0096] A first insulating member 510 is placed between the second plate portion 304 and the second sealing plate 130. A second insulating member 520 is placed between the positive terminal 302 and the second sealing plate 130. A third insulating member 530 is placed between the second electrode terminal side current collector 450 and the second sealing plate 130.

[0097] However, the positive terminal 302 may be electrically connected to the second sealing plate 130. Alternatively, the second sealing plate 130 may also function as the positive terminal 302.

[0098] A spacer 600 (second spacer) is positioned between the second sealing plate 130 and the electrode body 200. This spacer 600 (second spacer) suppresses large movements of the electrode body 200 within the case 100. The spacer 600 is made of an insulating resin material. The spacer 600 includes a first component 610 and a second component 620. The first component 610 and the second component 620 are engaged with each other at engaging portions (not shown) at both ends in the Z direction.

[0099] A resin insulating sheet 700 (electrode holder) is placed between the electrode body 200 and the case body 110.

[0100] On the second electrode (positive electrode) side of the secondary battery 1, a resin insulating sheet 700 (electrode holder) is placed between the electrode body 200 and the case body 110. More specifically, the insulating sheet 700 covers the electrode body 200 and also surrounds the side of the spacer 600 (second spacer) on the case body 110 side, so the spacer 600 (second spacer) is covered by the insulating sheet 700. Furthermore, the insulating sheet 700 is connected to the spacer 600 by a method described later.

[0101] Furthermore, the third insulating member 530 is positioned between the spacer 600 (second spacer) and the second sealing plate 130. Alternatively, the spacer 600 may be placed in contact with the third insulating member 530. Alternatively, the spacer 600 may be placed in contact with the second sealing plate 130.

[0102] (Spacer 600) The detailed structure of the spacer 600 will be described with reference to Figures 15 and 16. Figure 15 is a first perspective view showing the overall configuration of the spacer 600, and Figure 16 is a second perspective view taken from the opposite side of the first perspective view. The first perspective view is a view taken from the first sealing plate 120 (second sealing plate 130) side when the spacer 600 is placed between the first sealing plate 120 (second sealing plate 130) and the electrode body 200.

[0103] The spacer 600 is made of an insulating resin material. The spacer 600 includes a first part 610 and a second part 620. When the first part 610 and the second part 620 are coupled to each other, it has an annular shape and is configured to be divisible into two parts along the Y direction. As the spacer 600 is made of two parts in this way, it is positioned to sandwich the electrode tab. Note that the spacer 600 is not limited to being made of two parts, but may be made of one part as shown in Figure 35 below, or it may be made of two or more parts.

[0104] The first component 610 has a side wall portion 611 extending in the Z direction, and connecting walls 612 and 614 extending from both ends of the side wall portion 611 toward the second component 620. A plate portion 617 is provided at the corner of the connection between the side wall portion 611 and the connecting wall 612. The plate portion 617 is provided with a slit-shaped through hole 617s. Similarly, a plate portion 618 is provided at the corner of the connection between the side wall portion 611 and the connecting wall 614. The plate portion 618 is provided with a slit-shaped through hole 618s. A protrusion 616 is provided at the X-direction end of the side wall portion 611, projecting toward the second component 620 in the Y direction.

[0105] The plate portions 617 and 618 described above are located on the end face side of the electrode body. These plate portions may or may not be in contact with the end face of the electrode body, but even if they are not in contact, the shortest distance is preferably within 2 mm, and more preferably within 1 mm. Furthermore, by providing the through hole 618s, when the secondary battery 1 shown in Figure 1 is placed with the Z direction facing upward (the direction in which the first openings 113 and second openings 114 at both ends of the case body 110 are arranged to the left and right), even if the electrolyte that is pushed out of the electrode body during charging (generally the electrode plates expand) flows out to the outside of this part, it is made easier for it to return into the electrode body during discharge (generally the electrode plates contract).

[0106] In the spacer 600 (first spacer) positioned between the first sealing plate 120 and the electrode body 200, the protrusion 616 constitutes the first protrusion, and in the spacer 600 (second spacer) positioned between the second sealing plate 130 and the electrode body 200, it constitutes the third protrusion.

[0107] The second part 620 has a side wall portion 621 extending in the Z direction, and connecting walls 622 and 624 extending from both ends of the side wall portion 621 toward the first part 610. A plate portion 627 is provided at the corner of the connection between the side wall portion 621 and the connecting wall 622. The plate portion 627 is provided with a slit-shaped through hole 627s. Similarly, a plate portion 628 is provided at the corner of the connection between the side wall portion 621 and the connecting wall 624. The plate portion 628 is provided with a slit-shaped through hole 628s. A protrusion 626 is provided at the X-direction end of the side wall portion 621, projecting toward the first part 610 in the Y direction.

[0108] The plate portions 627 and 628 described above are located on the end face side of the electrode body. These plate portions may or may not be in contact with the end face of the electrode body, but even if they are not in contact, the shortest distance is preferably within 2 mm, and more preferably within 1 mm. Furthermore, by providing the through hole 628s, when the secondary battery 1 shown in Figure 1 is placed with the Z direction facing upward (the direction in which the first openings 113 and second openings 114 at both ends of the case body 110 are arranged to the left and right), even if the electrolyte that is pushed out of the electrode body during charging (generally the electrode plates expand) flows out to the outside of this part, it is made easier for it to return into the electrode body during discharge (generally the electrode plates contract).

[0109] In the spacer 600 (first spacer) positioned between the first sealing plate 120 and the electrode body 200, the protrusion 626 constitutes a second protrusion, and in the spacer 600 (second spacer) positioned between the second sealing plate 130 and the electrode body 200, it constitutes a fourth protrusion.

[0110] Between the connecting wall 612 and the connecting wall 622, there are mutually detachable engaging claws 613 and engaging grooves 623. Similarly, between the connecting wall 614 and the connecting wall 624, there are mutually detachable engaging claws 615 and engaging grooves 625.

[0111] Furthermore, when comparing the thickness in the X direction of the spacer 600 placed on the first electrode tab 220 and the third electrode tab 270 (thickness on the negative electrode side) with the thickness in the X direction of the spacer 600 placed on the second electrode tab 250 and the fourth electrode tab 280 (thickness on the positive electrode side), the thickness on the positive electrode side can be made larger than the thickness on the negative electrode side. This is because, on the negative electrode side, the thickness of the foil used for the first electrode tab 220 and the third electrode tab 270 is thinner, so the space between the electrode body and the sealing body is smaller on the negative electrode side than on the positive electrode side, thereby improving the mounting efficiency of the electrode body.

[0112] (Manufacturing process for secondary battery 1) The method for manufacturing a secondary battery according to this embodiment will now be described. Figure 17 is a flowchart showing the method for manufacturing a secondary battery according to Embodiment 1. Figure 18 is a perspective view showing the state before the two electrode bodies of the secondary battery according to Embodiment 1 overlap. Figure 19 is a cross-sectional view of the electrode body and current collector shown in Figure 18, taken from line XIX-XIX.

[0113] As shown in Figure 17, in the method for manufacturing a secondary battery according to this embodiment, first, the first electrode body 201 and the second electrode body 202 are manufactured (step S1). The first electrode tab 220, the second electrode tab 250, the third electrode tab 270, and the fourth electrode tab 280 are each cut to a portion of their tip so that when bundled together, their tip lengths are the same.

[0114] As shown in Figures 17 to 19, after the first electrode body 201 and the second electrode body 202 are manufactured, the first electrode tab 220 is joined to the first current collector 410 (step S2). The first electrode tab 220 is joined to the first current collector 410 at the joining point 411. Next, the third electrode tab 270 is joined to the third current collector 430 (step S3). The third electrode tab 270 is joined to the third current collector 430 at the joining point 431.

[0115] Next, the first electrode body 201, the second current collector 420, and the second electrode body 202 are arranged in this order in the first direction (DR1 direction). The second electrode tab 250 is placed on one side of the second current collector 420 in the first direction (DR1 direction). With the fourth electrode tab 280 placed on the other side of the second current collector 420 in the first direction (DR1 direction), the second electrode tab 250 and the fourth electrode tab 280 are joined to the second current collector 420 (step S4). The second electrode tab 250 and the fourth electrode tab 280 are joined to the second current collector 420 at the joining point 421.

[0116] In the height direction of the first electrode body 201 and the second electrode body 202, the first current collector 410, the second current collector 420, and the third current collector 430 are positioned off-center to one side of the center of the first electrode body 201 and the second electrode body 202. This allows the current collectors to be made shorter, thus enabling them to be made smaller.

[0117] Note that the first current collector 410, the second current collector 420, and the third current collector 430 are not limited to this configuration. The first current collector 410, the second current collector 420, and the third current collector 430 may be positioned in the center of the first electrode body 201 and the second electrode body 202 in the height direction of the first electrode body 201 and the second electrode body 202. In this case, in the height direction of the first electrode body 201 and the second electrode body 202, the first electrode tab 220, the second electrode tab 250, the third electrode tab 270, and the fourth electrode tab 280 are each positioned in the center of the first electrode body 201 and the second electrode body 202 in accordance with the first current collector 410, the second current collector 420, and the third current collector 430.

[0118] Furthermore, the order in which the first current collector 410, the second current collector 420, and the third current collector 430 are joined to the first electrode body 201 and the second electrode body 202 is not limited to the above, and the order may be changed. The step of joining the first current collector 410 and the third current collector 430 to the first electrode body 201 and the second electrode body 202 is preferably performed before the step of stacking the first electrode body 201 and the second electrode body 202, which will be described later, and is preferably performed before the step of joining the second current collector 420 to the first electrode body 201 and the second electrode body 202.

[0119] Next, after joining the second electrode tab 250 and the fourth electrode tab 280, the second electrode tab 250 and the fourth electrode tab 280 are bent in the thickness direction of the first electrode body 201 and the second electrode body 202 (in a direction perpendicular to the DR1 direction in Figures 16 and 17) to overlap the first electrode body 201 and the second electrode body 202 (step S5). In other words, the first electrode body 201 and the second electrode body 202 are brought together.

[0120] "Overlapping the first electrode and the second electrode" means that the first electrode and the second electrode may be directly overlapped, or other components may be placed between the first electrode and the second electrode. Furthermore, the first electrode and the second electrode may or may not be fixed with tape or the like. In addition, the first electrode, the second current collector and the second electrode do not have to be arranged in a straight line in the first direction (DR1 direction), and the first electrode or the second electrode may be inclined with respect to the second current collector in the first direction (DR1 direction).

[0121] By overlapping the first electrode body 201 and the second electrode body 202, the second electrode tab 250 and the fourth electrode tab 280 are bent so that they are closer to each other with respect to the second current collector 420. Also, the first electrode tab 220 and the third electrode tab 270 are bent so that their tips face each other.

[0122] Figures 17 and 20 to 24 are perspective views showing the electrode body with the holder and spacer attached. As shown in Figure 24, the spacer 600 and insulating sheet 700 are then assembled onto the electrode body 200 (step S6).

[0123] As shown in Figure 20, the insulating sheet 700 covers the entire outer circumference of the electrode body 200 and also surrounds the sides of the spacers 600 (first spacer and second spacer) on the case body 110 side, so the spacers 600 are covered by the insulating sheet 700. Furthermore, the insulating sheet 700 is connected to the spacers 600 by fixing means 710.

[0124] In this manner, the spacer 600 is covered by the insulating sheet 700 together with the electrode body 200. As a result, when inserting the electrode body 200, which is covered by the insulating sheet 700, into the case body 110, the spacer 600 can be stably inserted into the case body together with the electrode body 200. This allows the spacer 600 to be positioned more accurately in the predetermined location within the case body 110. Furthermore, damage to the electrode tab can be effectively suppressed.

[0125] Here, it is preferable that the length of the spacers 600 (first spacer and second spacer) in the thickness direction (Y direction) of the main body of the electrode body 200 is smaller than the thickness of the main body of the electrode body 200. The comparison is made based on the portion of the electrode body 200 where the length of the spacers 600 in the thickness direction is greatest.

[0126] Furthermore, it is preferable that the height of the spacers 600 (first spacer and second spacer) in the height direction (Y direction) of the main body of the electrode body 200 is smaller than the height of the main body of the electrode body 200. The comparison is made based on the portion of the main body of the electrode body 200 where the height of the spacers 600 is greatest.

[0127] As a result, the electrode body 200 is fixed by the insulating sheet 700, which improves the ease of inserting the electrode body 200 into the case 100.

[0128] The configuration of the insulating sheet 700 will be described with reference to Figures 21 to 23. Figure 21 shows the insulating sheet 700 in an unfolded state, Figure 22 shows the insulating sheet 700 in another configuration in an unfolded state, and Figure 23 is the XXIII-XXIII view shown in Figure 20.

[0129] The insulating sheet 700 has a rectangular shape when unfolded, and it is preferable that fold lines L1 are provided in advance at positions corresponding to the corners of the electrode body 200 when it is wrapped around the outer surface of the electrode body 200.

[0130] When the insulating sheet 700 is wrapped around the outer surface of the electrode body 200, the insulating sheet 700 should overlap one side edge region T1 and the other side edge region T2 on the side of the electrode body 200, on the side of the electrode body 200, where the area of ​​the insulating sheet 700 is smaller than that of the first electrode body side surface 200S1 facing the pair of second side surfaces 112 of the case body 110 shown in Figures 3 and 4.

[0131] Furthermore, the side end region T1 is provided with an opening 700h for fixing the side end region T1 to the side end region T2 when it overlaps with the side end region T2. ​​In the illustration, the opening 700h is rectangular in shape, but it is not limited to a rectangular shape and may be circular or any other shape. Furthermore, as shown in Figure 22, the opening may be a notch 700k.

[0132] The opening 700h or notch 700k is preferably positioned to face an area within 40 mm of the end of the insulating sheet 700 on the winding end side (upper end in Figures 21 and 22) in the circumferential direction (up and down direction in Figures 21 and 22) when the insulating sheet 700 is wound, more preferably within an area within 30 mm, and even more preferably within an area within 20 mm.

[0133] Furthermore, it is preferable that the opening 700h or notch 700k be formed in the vicinity of the end of the insulating sheet 700 on the winding side (the lower end in Figures 21 and 22) in the circumferential direction when the insulating sheet 700 is wound (for example, within a range of 30 mm from the end on the winding side).

[0134] Referring to Figure 23, the side end regions T1 and T2 are fixed to the spacer 600 using fixing means 710 such as welding, ultrasonic bonding, tape application, adhesive bonding, fitting, or hooking, using the opening 700h. Welding and ultrasonic bonding are particularly preferred as fixing means 710. Heat welding is preferred for welding. The area in which the insulating sheet 700 is fixed to the spacer 600 is limited to the area around the opening 700h, and it is preferable that no joints are provided in the overlapping area between the other side end regions T1 and T2. In particular, in the overlapping area between the other side end regions T1 and T2, it is preferable that there is an area in the region facing the electrode body 200 where no joints are formed between the insulating sheets 700. It is preferable that there is a gap in the part where no joint is provided, or that a gap is created when the gas discharge valve is operated. This is because when the pressure inside the case 100 exceeds a predetermined value, these gaps become a path for discharging the gas inside the case 100 to the outside. Therefore, it is preferable to fix the insulating sheet 700 to the spacer 600 such that one side end region T1 and the other side end region T2 of the insulating sheet 700 overlap at the second side portion 112B where the joint portion 115 is provided.

[0135] The insulating sheet 700 does not necessarily need to cover the entire surface of the electrode body 200. Preferably, the insulating sheet 700 covers an area of ​​50% or more, more preferably 70% or more, of the outer surface of the electrode body. Preferably, the insulating sheet 700 covers the entirety of four of the six surfaces of the substantially rectangular parallelepiped (flat-shaped) electrode body 200, excluding the two surfaces on which the first electrode tab 220 and the second electrode tab 250 are formed.

[0136] Furthermore, the insulating sheet 700 does not need to cover the entire surface of the spacer 600. For example, the surface of the spacer 600 facing the inner surface of the case body 110 may be exposed.

[0137] Figure 25 is a perspective view showing the first current collector with the first sealing plate attached. Figure 26 is a cross-sectional view of the electrode body and current collector shown in Figure 25, taken along line XXVI-XXVI.

[0138] The negative electrode terminal 301 and the first electrode terminal side current collector 440 are attached to the first sealing plate 120 via the second insulating member 520 and the third insulating member 530. The connection of the first plate portion 303 to the negative electrode terminal 301 can be made at any time.

[0139] As shown in Figures 17, 25, and 26, the first electrode tab 220 is joined to the first current collector 410, the third electrode tab 270 is joined to the third current collector 430, and the first electrode body 201 and the second electrode body 202 are superimposed. Then, the first current collector 410 and the third current collector 430 are electrically connected to the negative electrode terminal 301 via the first electrode terminal side current collector 440 (S7 step / connection step). Since the negative electrode terminal 301 is fixed to the first sealing plate 120 via the second insulating member 520, the first electrode tab 220 and the third electrode tab 270 are connected to the first sealing plate 120. It is also possible to perform the S7 / connection process before the S6 process.

[0140] The first electrode terminal-side current collector 440, which is attached to the first sealing plate 120, is brought into contact with the first current collector 410 and the third current collector 430 from the X direction. The first electrode terminal-side current collector 440 and the first current collector 410 and the third current collector 430 are joined by laser welding from between the first sealing plate 120 and the insulating sheet 700.

[0141] In this case, the outer edge of the base of the first electrode tab 220 should be in contact with the protrusion 616 provided on the spacer 600. Similarly, the outer edge of the base of the third electrode tab 270 should be in contact with the protrusion 626 provided on the spacer 600.

[0142] Figure 27 is a perspective view showing the electrode body inserted into the case body. As shown in Figures 17 and 27, next, the first electrode body 201 and the second electrode body 202 are superimposed, and then the first electrode body 201 and the second electrode body 202 are inserted into the case body 110 from the first opening 113, with the second current collector 420 side leading (step S8).

[0143] By bringing the first sealing plate 120 and the main bodies of the electrode bodies 200 (first electrode body 201 and second electrode body 202) closer together, the first electrode tab 220 and the third electrode tab 270 are curved. It is preferable to bring the first sealing plate 120 and the case body 110 closer together by bringing the first sealing plate 120 and the main bodies of the electrode bodies 200 placed inside the case body 110 closer together. As shown in Figure 13, the curved state of the first electrode tab 220 starts from a convex portion 616 (first concave portion) that abuts the bottom edge of the first electrode tab 220, and the first electrode tab 220 facing the convex portion 616 starts to curve inward, and the first electrode tab 220 is bent so that the curved portion 221 (first curved portion) is formed. Similarly, the curved state of the third electrode tab 270 begins with a convex portion 626 (second convex portion) that abuts the base of the third electrode tab 270, and the third electrode tab 270 opposite the convex portion 626 starts to curve inward, and the curved portion 271 (second curved portion) is formed as the third electrode tab 270 is bent. As shown in Figure 13, it is preferable that the first electrode tab 220 and the third electrode tab 270 are curved to a state that is substantially symmetrical.

[0144] After the first sealing plate 120 is brought into contact with the case body 110, the first sealing plate 120 is temporarily joined to the case body 110. Through this temporary joining, the first sealing plate 120 is partially joined to the first opening 113 of the case body 110. This positions the first sealing plate 120 relative to the case body 110.

[0145] When inserting the electrode body 200 into the case body 110, the electrode body 200 may be pulled from the second current collector 420 side, or pushed from the first current collector 410 and third current collector 430 side. When the electrode body 200 is pushed from the first current collector 410 and third current collector 430 side, the first electrode tab 220 and the third electrode tab 270 can be bent at the same time.

[0146] Figure 28 is a perspective view showing the second current collector with the second sealing plate attached. Figure 29 is a cross-sectional view of the electrode body and current collector shown in Figure 28, taken along the XXV-XXV line. Note that the case body 110 is omitted in Figure 29.

[0147] As shown in Figures 17, 28, and 29, the first electrode body 201 and the second electrode body 202 are then inserted into the case body 110, and the second current collector 420 is electrically connected to the positive terminal 302 (step S9).

[0148] Specifically, the positive electrode terminal 302 and the second electrode terminal-side current collector 450 are attached to the second sealing plate 130 via an insulating member. The second electrode terminal-side current collector 450 is brought into contact with the second current collector 420 from the X direction. The second electrode terminal-side current collector 450 and the second current collector 420 are joined by laser welding from between the second sealing plate 130 and the insulating sheet 700. Note that the connection of the second plate portion 304 to the positive electrode terminal 302 can be done at any time.

[0149] As shown in Figure 29, the second electrode tab 250 and the fourth electrode tab 280 are bent from an extended state to a curved state in opposite directions, such that the tip portions 252 and 282 located at the end opposite to the side to which the second electrode is connected move closer to each other. As a result, the same bent shape is symmetrical. Specifically, the second electrode tab 250 is bent from an extended state to a curved state by contacting the protrusion 616 (third protrusion) provided on the spacer 600 (second spacer) and gradually bending it so that it has a recessed position opposite to the protrusion 616. Similarly, the fourth electrode tab 280 is bent from an extended state to a curved state by contacting the protrusion 626 (fourth protrusion) provided on the spacer 600 (first spacer) and gradually bending, so that it has a recessed area opposite to the protrusion 626. As a result, the same bent shape is symmetrical.

[0150] By bringing the second sealing plate 130 closer to the main body of the electrode body 200, the second electrode tab 250 and the fourth electrode tab 280 are curved. At this time, the second sealing plate 130 and the case body 110 come closer together. As shown in Figure 14, the curved state of the second electrode tab 250 starts from the convex portion 616 (third convex portion) that abuts the bottom edge of the second electrode tab 250, and the second electrode tab 250 opposite the convex portion 616 begins to curve inward, and the curved portion 251 (first curved portion) is formed as the second electrode tab 250 is bent. Similarly, the curved state of the fourth electrode tab 280 begins with a convex portion 626 (fourth convex portion) that abuts the base of the fourth electrode tab 280, and the fourth electrode tab 280 opposite the convex portion 626 starts to curve inward, causing the fourth electrode tab 280 to bend and form a curved portion 281 (second curved portion).

[0151] After the first sealing plate 120 is brought into contact with the case body 110, the second sealing plate 130 is tack-welded to the case body 110. Through this tack-welding, the second sealing plate 130 is partially joined to the second opening 114 of the case body 110. This positions the second sealing plate 130 relative to the case body 110.

[0152] Furthermore, as shown in Figures 26 and 29, the distance D1 from the end face of the case body to the portion of the sealing plate that is to contact the end face of the case body is preferably 20 mm or less, more preferably 15 mm or less, and even more preferably 10 mm or less. When the electrode tab is extended, the distance D2 from the current collector to the end of the electrode body (the base of the electrode tab) is preferably 40 mm or less, more preferably 30 mm or less, and even more preferably 20 mm or less. With this configuration, a battery with a higher volumetric energy density is obtained.

[0153] Furthermore, as shown in Figures 13 and 14, the distance D3 from the current collector to the end of the electrode body (the base of the electrode tab) in the state where the sealing plate and the case body are in contact is preferably 15 mm or less, more preferably 10 mm or less, and even more preferably 5 mm or less.

[0154] Figure 30 is a perspective view showing the configuration of a secondary battery according to Embodiment 1. As shown in Figures 17 and 30, the first sealing plate 120 and the second sealing plate 130 are then joined to the case body 110 (step S10). The first sealing plate 120 seals the first opening 113 of the case body 110, and the second sealing plate 130 seals the second opening 114 of the case body 110. As a result, the first electrode body 201 and the second electrode body 202 are housed in the case 100.

[0155] After the above-described process, inspections such as leak testing are performed (S11 step). After the leak testing, the secondary battery 1 is dried to remove moisture from inside the case 100. Then, electrolyte is injected into the inside of the case 100 through the injection hole 134. When injecting the electrolyte, the case 100 is tilted with the second sealing plate 130 facing upwards and the first sealing plate 120 facing downwards, and the electrolyte is injected into the inside of the case 100 through the injection hole 134 of the second sealing plate 130. After that, degassing and charging are performed. During degassing and charging, the injection hole 134 may be temporarily sealed. After that, the injection hole is sealed, and the secondary battery 1 is completed.

[0156] In the manufacturing method and secondary battery 1 according to Embodiment 1 of this technology, the first electrode body 201, the second current collector 420 composed of a single component, and the second electrode body 202 are arranged in this order in the first direction (DR1 direction). After joining the second electrode tab 250 and the fourth electrode tab 280 formed on the first electrode body 201 and the second electrode body 202 to the second current collector 420, the first electrode body 201 and the second electrode body 202 are overlapped in the thickness direction. This allows for the formation of separate electrode tabs on the first electrode body 201 and the second electrode body 202, and the first electrode body 201 and the second electrode body 202 can be constructed by bending the second electrode tab 250 and the fourth electrode tab 280, respectively. This configuration allows for a shorter electrode tab compared to the case where the first electrode body 201 and the second electrode body 202 form a single electrode tab and this electrode tab is folded. Furthermore, this configuration makes it possible to shorten the length of each tab compared to the case where the second electrode tab 250 and the fourth electrode tab 280 of the first electrode body 201 and the second electrode body 202 are connected to the second current collector 420 after they have been stacked. As a result, the volume occupied by the electrode tabs can be reduced, thereby improving the energy density of the secondary battery 1. In addition, forming separate electrode tabs in the first electrode body 201 and the second electrode body 202, and then bending each of these electrode tabs to form the first electrode body 201 and the second electrode body 202, makes the electrode tabs easier to bend compared to the case where the first electrode body 201 and the second electrode body 202 form a single electrode tab. This makes it easier to connect the electrode tabs to the current collector, allowing for the stable manufacture of the secondary battery. In particular, the ability to stably manufacture the secondary battery 1 increases the reliability of the connection between the electrode tabs and the current collector.

[0157] In the manufacturing method of the secondary battery 1 according to Embodiment 1 of this technology, after the second electrode tab 250 and the fourth electrode tab 280 are joined by the second current collector 420, the first electrode body 201 and the second electrode body 202 are inserted into the case body 110 from the side of the second current collector 420, which is joined together, thereby making it easier to insert the electrode body 200 into the case body 110.

[0158] Furthermore, by providing the spacer 600 with protrusions 616 that contact the bottom of the first electrode tab 220 and the bottom of the second electrode tab 250, and protrusions 626 that contact the bottom of the third electrode tab 270 and the bottom of the fourth electrode tab 280, the protrusions that contact the bottom of the electrodes act as a starting point, causing the electrode tabs facing the protrusions to begin bending inward, thus easily guiding the folding of the electrode tabs in the appropriate direction.

[0159] Furthermore, since the entire perimeter of the spacer 600 is covered by the insulating sheet 700, the electrode tabs are also covered by the insulating sheet 700. As a result, when inserting the electrode body 200, which is covered by the insulating sheet 700, into the case body 110, the electrode tabs are protected, unintentional damage to the electrode tabs is suppressed, and a highly reliable secondary battery can be provided.

[0160] In the manufacturing method and secondary battery 1 according to Embodiment 1 of this technology, separate electrode tabs are formed in the first electrode body 201 and the second electrode body 202, and the electrode bodies 200 that constitute the first electrode body 201 and the second electrode body 202 by bending each of these electrode tabs can be applied to a case body 110 having a first opening 113 and a second opening 114 located at the end opposite to the first opening 113. As a result, when the first opening 113 and the second opening 114 of the case body 110 are arranged side by side in the horizontal direction, the secondary battery 1 can be made lower in height.

[0161] In the manufacturing method of the secondary battery 1 and the secondary battery 1 according to Embodiment 1 of this technology, the first electrode tab 220 and the third electrode tab 270 are curved in opposite directions such that the tip portions 222 and 272 located at the end opposite to the side to which the first electrode is connected are closer to each other. This makes it possible to easily form the electrode tabs from the outside in the thickness direction of the electrode body.

[0162] In the manufacturing method and secondary battery 1 according to Embodiment 1 of this technology, compared to the case where separate current collectors are connected to each electrode tab of the first electrode body 201 and the second electrode body 202, the electrode tabs can be connected by a second current collector 420 which is composed of a single integrated part. This reduces the number of connection points for the constituent members and increases the reliability of the connection between the electrode tabs and the current collector.

[0163] The secondary batteries according to Embodiments 2 to 4 will be described below. Since the configuration of the spacers in these embodiments differs from that of secondary battery 1 according to Embodiment 1, the configurations that are the same as those of secondary battery 1 according to Embodiment 1 of this technology will not be repeated in the description.

[0164] (Embodiment 2) Referring to Figures 31 to 34, the configuration of the secondary battery according to Embodiment 2 is shown. Figure 31 is a cross-sectional view corresponding to the XXVI-XXVI cross-section of the electrode body and current collector shown in Figure 25, Figure 32 is a cross-sectional view showing the electrode tab in a bent state, Figure 33 is a first perspective view showing the overall configuration of the spacer, and Figure 34 is a second perspective view showing the overall configuration of the spacer.

[0165] Referring to Figure 31, in the secondary battery according to Embodiment 2, the tips 222A and 272A of the first electrode tab 220A and the third electrode tab 270A are bent in the same direction in the Y direction.

[0166] Subsequently, the first electrode body 201A and the second electrode body 202A are inserted into the case body, and the first sealing plate 120 is brought into contact with the case body. As a result, the first electrode tab 220A and the third electrode tab 270A are bent from an extended state to a curved state in the same direction, so that the tips of the ends located on the side opposite to the side to which the first electrode is connected face the same direction. Consequently, the tips 222A and 272A are bent in a state where identical bends are arranged side by side, so that the tips face the same direction. Specifically, the first electrode tab 220 is bent gradually starting from the protrusion 616 (first protrusion) provided on the spacer 600 (first spacer), so that the first electrode tab 220 is curved from an extended state to a curved state, so that it has a recess where the position opposite the protrusion 616 is recessed. Similarly, the third electrode tab 270 is gradually bent starting from the protrusion 626 (second protrusion) provided on the spacer 600 (first spacer) so that it changes from an extended state to a curved state, and is bent in a curved manner so that it has a recess where the position opposite the protrusion 626 is recessed. As a result, it is bent into a state in which identical bent shapes are lined up.

[0167] To facilitate the curvature of the tip portions 222A and 272A in the same direction, the spacer 600A between the first electrode tab 220A and the third electrode tab 270A is provided with an intermediate side wall 650 extending in the Z direction between the side wall portions 611 and 621. The X-direction end of the intermediate side wall 650 is provided with a protrusion 619 (third protrusion) that projects toward the second component 620 in the Y direction. On the other hand, the side wall portion 621 on the second component 620 side is not provided with a protrusion.

[0168] When the tips 222A and 272A of the first electrode tab 220A and the third electrode tab 270A are curved in the same direction in the Y direction, the first electrode body 201A and the second electrode body 202 can be configured as a single type of electrode body 200A.

[0169] As shown in Figure 32, when the first electrode tab 220A and the third electrode tab 270A are bent, the first electrode tab 220A has a curved portion 221 (first curved portion) and a tip portion 222. The first electrode tab 220A includes a recess 221a (first recess) in which the area facing the convex portion 616 provided on the spacer 600A is significantly recessed.

[0170] The third electrode tab 270A has a curved portion 271 (second curved portion) and a tip portion 272. The third electrode tab 270A includes a recessed portion 271a (third recess) in which the region facing the convex portion 619 provided on the spacer 600A is significantly recessed.

[0171] Although not shown in the illustrations, the same applies to the connection structure between the electrode body and the current collector on the second electrode (positive electrode) side of the secondary battery, as shown in Figures 14 and 29. Therefore, each of the second electrode tab 250 and the fourth electrode tab 280 is bent from an extended state to a curved state in the same direction, so that the tip located at the end opposite to the side to which the second electrode is connected faces the same direction. As a result, the tip portions 222A and 272A face the same direction, and the same bent shape is arranged side by side. Specifically, the second electrode tab 250 is bent gradually starting from the convex portion 616 (third convex portion) provided on the spacer 600 (second spacer) so that the second electrode tab 250 is curved from an extended state to a curved state, so that it has a recess where the position opposite the convex portion 616 is recessed. Similarly, the fourth electrode tab 280 is gradually bent starting from the convex portion 626 (fourth convex portion) provided on the spacer 600 (first spacer) so that the fourth electrode tab 280 changes from an extended state to a curved state. As a result of bending it so that the position opposite the convex portion 626 has a recess, the tip portions 222A and 272A face the same direction and are bent in a manner in which identical bends are lined up.

[0172] (Spacer 600A) The detailed structure of spacer 600A will be described with reference to Figures 33 and 34. Note that the same reference numerals are used for parts identical to those of spacer 600 in Embodiment 1 above, and redundant explanations will not be repeated.

[0173] The basic configuration of spacer 600A is the same as that of spacer 600 in Embodiment 1, except that the first component 610 is provided with an intermediate side wall 650 extending in the Z direction at a position between the side wall portion 611 and the side wall portion 621. The end of the intermediate side wall 650 in the X direction is provided with a protrusion 651 (third protrusion) that projects toward the second component 620 in the Y direction. On the other hand, the side wall portion 621 on the second component 620 side is not provided with a protrusion.

[0174] By employing a spacer 600A having this configuration, it becomes possible to position an intermediate side wall 650 having a protrusion 651 (third protrusion) between the first electrode tab 220A and the third electrode tab 270A.

[0175] (Embodiment 3) Referring to Figure 35, other forms of spacer 600B will be described. Note that the same reference numerals are used for parts identical to those of spacer 600 in Embodiment 1 above, and redundant explanations will not be repeated.

[0176] The spacer 600 described in Embodiment 1 above had a two-part structure including a first part 610 and a second part 620, but the spacer 600B shown in Figure 35 has an annular shape composed of only one part. It has an annular shape in which both sides of the short side walls 632 and 634 are connected by side wall portions 611 and 621. This annular shape can also be adopted for the spacer 600A of Embodiment 2.

[0177] Even when using spacer 600B with this configuration, it is possible to obtain the same effects and advantages as in embodiments 1 and 2 described above.

[0178] (Embodiment 4) Referring to Figures 36 to 38, the connection structure between the electrode body 200 and the current collector 400 when using other forms of spacer 600C will be described. Figure 36 is a cross-sectional view corresponding to XIII-XIII of the secondary battery shown in Figure 1, and Figures 37 and 38 are first and second perspective views showing the overall configuration of the spacer 600C.

[0179] Figure 36 shows the connection structure between the electrode body 200 and the current collector 400 on the first electrode (negative electrode) side of the secondary battery 1. The connection structure between the electrode body 200 and the current collector 400 on the second electrode (positive electrode) side of the secondary battery 1 is the same as shown in Figures 13 and 14, as the shape of the electrode tab is identical, so a description is omitted here. Furthermore, the same reference numerals are used for the spacer 600C in the same locations as the spacer 600 shown in Figures 15 and 16, and redundant explanations are not repeated.

[0180] In this embodiment, the spacer 600C is arranged such that the first part 610 and the second part 620 are back-to-back in the central part, resulting in the convex portions 616 and 626 being provided to extend outward from the central part.

[0181] Each of the first electrode tab 220 and the third electrode tab 270 is bent so that the tips 222 and 272 located at the end opposite to the side to which the first electrode is connected face in opposite directions, and the electrode tabs are bent from an extended state to a curved state in opposite directions. Specifically, the first electrode tab 220 is bent gradually starting from the protrusion 616 (first protrusion) provided on the spacer 600 (first spacer) so that it is curved and bent so that it has a recess where it is indented opposite to the protrusion 616. Similarly, the third electrode tab 270 is bent gradually starting from the protrusion 626 (second protrusion) provided on the spacer 600 (first spacer) so that it is curved and bent so that it has a recess where it is indented opposite to the protrusion 626. As a result, the same folding configuration becomes symmetrical (opposite to the folding configuration shown in Figure 13).

[0182] Even when using spacer 600C with this configuration, it is possible to obtain the same effects and advantages as in embodiments 1 and 2 described above.

[0183] In the embodiments described above, as shown in Figures 18 and 19, the first electrode body 201, the second current collector 420 composed of a single component, and the second electrode body 202 are arranged in this order in the first direction (DR1 direction), and the second electrode tabs 250 and 4 electrode tabs 280 formed on the first electrode body 201 and the second electrode body 202 are joined to the second current collector 420, and then the first electrode body 201 and the second electrode body 202 are stacked on top of each other in the thickness direction. However, the invention is not limited to this configuration. The second electrode tabs 250 and 4 electrode tabs 280 may be joined to separate current collectors, and the first electrode body 201 and the second electrode body 202, which are not connected, may be stacked on top of each other in the thickness direction. In this case, both the negative electrode side and the positive electrode side will have the structure shown in Figure 13.

[0184] As a spacer in this disclosure, the spacer 600B of Embodiment 3 may also have a shape in which one of the pair of side wall portions 611 and protrusions 626 is removed.

[0185] While embodiments of the present technology have been described above, the embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present technology is defined by the claims, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of symbols]

[0186] 1 Secondary battery, 100 Case, 110 Case body, 111 First side section, 112, 112A, 112B Second side section, 113 First opening, 114 Second opening, 115 Joint, 120 First sealing plate, 130 Second sealing plate, 134 Liquid injection hole, 150 Gas discharge valve, 200, 200A Electrode body, 201, 201A First electrode body, 202, 202A Second electrode body, 205 First end, 206 Second end, 207 Third end, 208 Fourth end, 210 Negative electrode plate, 210S Negative electrode base plate, 211 Negative electrode core body, 212 Negative electrode active material layer, 220, 220A First electrode tab, 221, 251, 271, 281 Curved section, 221a, 251a, 271a, 281a Recessed section, 222, 222A, 252, 272, 272A, 282 Tip section, 230 Negative electrode tab, 240 Positive electrode plate, 240S Positive electrode base plate, 241 Positive electrode core, 242 Positive electrode active material layer, 243 Positive electrode protective layer, 250 Second electrode tab, 260 Positive electrode tab, 270, 270A Third electrode tab, 280 Fourth electrode tab, 300 Electrode terminal, 301 Negative electrode terminal, 302 Positive electrode terminal, 303 First plate section, 304 Second plate section, 400 Current collector, 400A Negative electrode current collector, 400B Positive electrode current collector, 410 First current collector, 411, 421, 431 Joint section, 420 430 Second current collector, 440 Third current collector, 440 First electrode terminal side current collector, 450 Second electrode terminal side current collector, 510 First insulating member, 520 Second insulating member, 530 Third insulating member, 600, 600A, 600B, 600C Spacer, 610 First part, 611, 621 Side wall, 612, 614, 622, 624 Coupling wall, 613, 615 Engaging claw, 616, 619, 626, 651 Protrusion, 617, 618, 627, 628 Plate, 617s, 618s, 627s, 628s Through hole, 620 Second part, 623, 625 Engaging groove, 632, 634 Short side wall, 650 Intermediate side wall, 700 Insulating sheet.

Claims

1. An electrode body including a first electrode and a second electrode having a different polarity from the first electrode, A case for housing the electrode body, A first electrode tab is electrically connected to the first electrode and positioned at one end of the electrode body, A second electrode tab is electrically connected to the second electrode and positioned at the other end of the electrode body, A first spacer positioned opposite the first electrode tab, A second spacer positioned opposite the second electrode tab, An insulating sheet is arranged to cover the electrode body, the first spacer and the second spacer, Equipped with, The insulating sheet and the first spacer are connected, The insulating sheet and the second spacer are connected. The aforementioned case is, A case body having a first opening at one end and a second opening at the other end, A first sealing plate that seals the first opening and is welded to the case body, The case includes a second sealing plate that seals the second opening and is welded to the case body, The first electrode tab is positioned at the end of the electrode body on the side of the first sealing plate, The second electrode tab is positioned at the end of the electrode body on the second sealing plate side, The insulating sheet has overlapping portions where the insulating sheets overlap each other. In the overlapping portion, the region facing the electrode body has a region where no joint portion is formed between the insulating sheets. Secondary battery.

2. In the region where no joint is formed between the insulating sheets, there is a gap that allows gas to pass through the gap between the insulating sheets, between the insulating sheet and the electrode body, and between the insulating sheet and the case. The secondary battery according to claim 1.

3. The first electrode terminal is attached to the first sealing plate. The second electrode terminal is attached to the second sealing plate. The first electrode tab is electrically connected to the first electrode terminal without an electrode body other than the electrode body, The second electrode tab is electrically connected to the second electrode terminal without an electrode body other than the electrode body. A secondary battery according to claim 1 or claim 2.

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