power storage device

Abstract

The power storage device of the present application includes: an electrode body (200) including a first electrode (240), a second electrode (210) having a polarity different from that of the first electrode (240), and a first electrode tab group (250, 280) electrically connected to the first electrode (240); a case (100) that houses the electrode body (200); a first conductive member (420) connected to the first electrode tab group (250, 280); a second conductive member (440) connected to the first conductive member (420); and an insulating member (460) disposed between the first conductive member (420) and the second conductive member (440), the first electrode tab group (250, 280) being located at an end portion of one side of the electrode body (200), and the insulating member (460) being connected to the first conductive member (420).

Description

Technical Field

[0001] This technology relates to energy storage devices. Background Technology

[0002] Japanese Patent No. 4537353 discloses a square secondary battery, which is configured such that an electrode assembly (25) is housed in a housing (14) having openings (14a, 14b) at both ends, and electrode terminals (21, 23) are respectively installed on a cover plate (33, 33') that seals the openings (14a, 14b).

[0003] In an energy storage device, a conductive connection is formed. Improving the reliability of this conductive connection is required. From this perspective, the battery described in Japanese Patent No. 4537353 still has room for improvement. Summary of the Invention

[0004] The purpose of this technology is to provide a highly reliable energy storage device.

[0005] This technology provides the following energy storage devices.

[0006] [1] An energy storage device, wherein the energy storage device comprises: an electrode body including a first electrode, a second electrode with a polarity different from the first electrode, and a first electrode tab assembly electrically connected to the first electrode; a housing housing the electrode body; a first conductive member connected to the first electrode tab assembly; a second conductive member connected to the first conductive member; and an insulating member disposed between the first conductive member and the second conductive member, wherein the first electrode tab assembly is located at one end of the electrode body, and the insulating member is connected to the first conductive member.

[0007] [2] According to the energy storage device described in [1], the first conductive member includes a first plate-shaped portion, the insulating member includes a second plate-shaped portion, and the first plate-shaped portion of the first conductive member is arranged to overlap with the second plate-shaped portion of the insulating member.

[0008] [3] According to the energy storage device described in [1] or [2], the first conductive member has a first end, the second conductive member has a second end adjacent to the first end, and a weld portion is formed at the first end and the second end to join the first conductive member and the second conductive member.

[0009] [4] An energy storage device according to any one of [1] to [3], wherein the first conductive member has a first through hole and the insulating member has a first protrusion, and by disposing the first protrusion in the first through hole, a fixing part is formed to fix the first conductive member and the insulating member to each other.

[0010] [5] According to the energy storage device described in [4], the first conductive member has a second through hole, the insulating member has a second protrusion, and the second protrusion is disposed in the second through hole in such a way that a gap is formed between the outer surface of the second protrusion and the inner surface of the second through hole.

[0011] [6] According to the energy storage device described in [4] or [5], the first conductive member has an outer surface located on the side opposite to the insulating member, the first protrusion has a first portion disposed in the first through hole, and a second portion with an outer diameter larger than the outer diameter of the first portion and disposed at a position closer to the front end side of the first protrusion than the first portion, the second portion is disposed outside the first through hole of the first conductive member, the second portion of the first protrusion abuts against the outer surface of the first conductive member, or the second portion of the first protrusion faces the outer surface of the first conductive member with a gap of 0.5 mm or less.

[0012] [7] The energy storage device described in any one of [4] to [6] includes a plurality of the aforementioned fixing parts.

[0013] [8] An energy storage device according to any one of [1] to [7], wherein the first conductive member has a first end, a first through hole and a second through hole, the second conductive member has a first protrusion, a second protrusion and a second end adjacent to the first end, a welding portion is formed at the first end and the second end to join the first conductive member and the second conductive member, and a fixing portion is formed by disposing the first protrusion in the first through hole to fix the first conductive member and the insulating member to each other, the second protrusion is disposed in the second through hole in such a way that a gap is formed between the outer surface of the second protrusion and the inner surface of the second through hole, and the first through hole is disposed at a position closer to the welding portion than the second through hole.

[0014] [9] An energy storage device according to any one of [1] to [8], wherein a joint portion of the first conductive member and the second conductive member is provided at the end side of one of the first conductive member and the second conductive member, wherein the first conductive member protrudes to the side opposite to the joint portion than the insulating member, and the insulating member protrudes to the side opposite to the joint portion than the second conductive member.

[0015]

[10] An energy storage device according to any one of [1] to [9], wherein the first conductive member has an outer surface located on the side opposite to the insulating member, the insulating member has a claw portion facing the outer surface of the first conductive member, and a fixing portion is formed by the claw portion to fix the first conductive member and the insulating member to each other.

[0016]

[11] An energy storage device according to any one of [1] to

[10] , wherein the first electrode tab group includes a first tab group and a second tab group formed independently, the first conductive member includes a first member and a second member provided as independent members, the first member is engaged with the first tab group, the second member is engaged with the second tab group, and the first member and the second member are connected to one insulating member.

[0017] The above and other objects, features, aspects and advantages of the present invention will become clear from the following detailed description relating to the invention, which is understood in conjunction with the accompanying drawings. Attached Figure Description

[0018] Figure 1 This is a front view showing the configuration of the secondary battery involved in the embodiment.

[0019] Figure 2 This indicates viewing from the direction of arrow II. Figure 1 The diagram shows the state of the secondary battery.

[0020] Figure 3 This indicates viewing from the direction of arrow III. Figure 1 The diagram shows the state of the secondary battery.

[0021] Figure 4 This indicates viewing from the direction of arrow IV. Figure 1 The diagram shows the state of the secondary battery.

[0022] Figure 5 This indicates viewing from the direction of arrow V. Figure 1 The diagram shows the state of the secondary battery.

[0023] Figure 6 yes Figure 1 The image shows a front cross-sectional view of a secondary battery.

[0024] Figure 7 This is a cross-sectional view of the negative electrode plate.

[0025] Figure 8 This is the front view of the negative electrode plate.

[0026] Figure 9 This is a cross-sectional view of the positive electrode plate.

[0027] Figure 10 This is the front view of the positive electrode plate.

[0028] Figure 11 yes Figure 1 The XI-XI cross-sectional view of the secondary battery shown.

[0029] Figure 12 yes Figure 1 The XII-XII cross-sectional view of the secondary battery is shown.

[0030] Figure 13 This is a flowchart illustrating a method for manufacturing a secondary battery according to one embodiment.

[0031] Figure 14 This is a perspective view showing the state of the secondary battery according to one embodiment before the two electrode bodies overlap.

[0032] Figure 15 yes Figure 14 The XV-XV sectional view of the electrode body and current collector shown.

[0033] Figure 16 It is a perspective view showing the state in which retainers and isolation components are installed on the electrode body.

[0034] Figure 17 This is a three-dimensional diagram showing the current collector on the negative side with a sealing plate installed.

[0035] Figure 18 yes Figure 17 The XVIII-XVIII sectional view of the electrode body and current collector shown.

[0036] Figure 19 This is a three-dimensional diagram showing the current collector on the positive side with a sealing plate installed.

[0037] Figure 20 It is a three-dimensional diagram showing the structure of a secondary battery.

[0038] Figure 21 This is a front view showing the state where the insulating component is connected to the first conductive component.

[0039] Figure 22 It means from Figure 21The state shown is a front view of one of the two first conductive components.

[0040] Figure 23 This indicates viewing from the opposite side (back side). Figure 22 The diagram shows the state of the indicated state.

[0041] Figure 24 It means Figure 22 and Figure 23 A three-dimensional diagram of the state.

[0042] Figure 25 This is a three-dimensional view showing the first conductive component.

[0043] Figure 26 It means Figure 22 A diagram of the first conductive and insulating components in the XXVI-XXVI cross section.

[0044] Figure 27 It means Figure 22 A diagram of the first conductive and insulating components in cross-sections XXVII-XXVII.

[0045] Figure 28 This is the front view showing the insulating component.

[0046] Figure 29 This is a front view showing the state where the second conductive component is installed on the insulating component.

[0047] Figure 30 This is a perspective view showing the state where a second conductive component is installed on an insulating component.

[0048] Figure 31 This is a diagram showing the collector structure on the positive side.

[0049] Figure 32 This diagram illustrates the process for forming the joint of a conductive component.

[0050] Figure 33 It means through Figure 32 The diagram shows the joint formed by the process shown.

[0051] Figure 34 This is a diagram showing the dimensional relationship between the second through hole and the second protrusion.

[0052] Figure 35 This is a diagram showing a modified example of the connection between the current collector and the insulating component. Detailed Implementation

[0053] The embodiments of this technology will be described below. Furthermore, the same or equivalent parts are sometimes labeled with the same reference numerals, and their descriptions are not repeated.

[0054] Furthermore, in the embodiments described below, when numbers, quantities, etc., are mentioned, the scope of this technology is not necessarily limited to those numbers, quantities, etc., unless specifically stated otherwise. Additionally, in the embodiments described below, each constituent element is not necessarily essential to this technology, unless specifically stated otherwise. Furthermore, this technology is not limited to technologies that must achieve all the effects mentioned in this embodiment.

[0055] Furthermore, in this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a component is included, other components besides that component may be included, or they may not be included.

[0056] Furthermore, when using geometric terms and terms indicating positional and directional relationships, such as "parallel," "orthogonal," "tilted at 45°," "coaxial," and "along," these terms allow for errors or slight variations. When using terms indicating relative positional relationships, such as "upper side" and "lower side," these terms are used to indicate relative positional relationships in a given state. Depending on the orientation of each mechanism (e.g., reversing the overall structure), the relative positional relationships can be reversed or rotated to any angle.

[0057] Furthermore, the dimensions of the components illustrated in this specification, such as width, length, and diameter, are not limited to the dimensions shown in the illustrations and can be appropriately changed. In this specification, there are instances where components are designated with ordinal numbers such as "first," "second," etc.; however, except where explicitly specified, these ordinal numbers do not limit priority or order.

[0058] In this specification, "battery" is not limited to lithium-ion batteries, but may include other batteries such as nickel-metal hydride batteries and sodium-ion batteries. In this specification, the positive and negative electrodes may be collectively referred to as "electrodes." Additionally, the positive and negative plates may be collectively referred to as "electrode plates."

[0059] In this specification, when terms such as “energy storage device,” “battery cell,” or “energy storage module” are used, “energy storage device,” “battery cell,” or “energy storage module” are not limited to batteries, battery cells, or battery modules, but may include capacitors, capacitor cells, or capacitor modules.

[0060] Battery cells can be installed in hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs). However, the use of battery cells is not limited to vehicle applications.

[0061] In this specification, the X direction is sometimes referred to as the "width direction" of the secondary battery, electrode body, and housing body; similarly, the Z direction is referred to as the "height direction" of the secondary battery or housing body; and similarly, the Y direction is referred to as the "thickness direction" of the secondary battery or housing body.

[0062] (The overall structure of a secondary battery)

[0063] Reference Figures 1-6 The overall structure of the secondary battery 1 will be described below. The secondary battery 1 includes a casing 100, an electrode body 200, electrode terminals 300, and a current collector 400. The casing 100 includes a casing body 110, a sealing plate 120, and a sealing plate 130.

[0064] When constructing a battery pack including secondary batteries 1, multiple secondary batteries 1 are stacked in their thickness direction. The stacked secondary batteries 1 can be constrained by a constraining component in the stacking direction (Y direction) to form a battery module, or the battery pack can be directly supported on the side of the battery pack housing without using a constraining component.

[0065] The casing body 110 is composed of a cylindrical component, preferably a square cylindrical component. This results in a square secondary battery 1. The casing body 110 is made of metal. Specifically, the casing body 110 is made of aluminum, aluminum alloy, iron, or iron alloy, etc.

[0066] like Figure 1 and Figure 2 As shown, sealing plates 120 and 130 are respectively provided at both ends of the housing body. The housing body 110 is formed, for example, by having the end edges of the bent plate-shaped members abut against each other (in... Figure 2 The junctions 115 (as illustrated in the example) are joined together (e.g., by laser welding or other energy line irradiation) to form a rectangular shape. The corners of the "rectangular" shape may also have a chamfered (R) shape. The secondary battery in this technology is not necessarily limited to a square secondary battery.

[0067] In this embodiment, the housing body 110 is formed to be longer in the width direction (X direction) than in the thickness direction (Y direction) and height direction (Z direction) of the secondary battery 1. The width of the housing body 110 in the X direction is preferably 30 cm or more. This allows for the construction of a relatively large (high-capacity) secondary battery 1. The height of the housing body 110 in the Z direction is preferably 20 cm or less, more preferably 15 cm or less, and even more preferably 10 cm or less. This allows for the construction of a relatively low-height secondary battery 1, for example, improving vehicle mounting capability.

[0068] The housing body 110 includes a pair of first side faces 111 and a pair of second side faces 112. The pair of first side faces 111 form part of the side faces of the housing 100. The pair of second side faces 112 form the bottom and top surfaces of the housing 100. The pair of first side faces 111 and the pair of second side faces 112 are arranged to intersect each other. The pair of first side faces 111 and the pair of second side faces 112 are connected at their respective ends. Preferably, the area of ​​each of the pair of first side faces 111 is larger than the area of ​​each of the pair of second side faces 112.

[0069] like Figure 5 As shown, an exhaust valve 150 is provided on one of the pair of second side portions 112, on the second side portion 112A. The exhaust valve 150 extends along the width direction (X direction) of the secondary battery 1. The exhaust valve 150 extends from the center of the housing body 110 in the X direction to a point that does not reach either end. The exhaust valve 150 can be modified as appropriate.

[0070] The thickness of the plate-shaped component in the exhaust valve 150 is thinner than the thickness of the plate-shaped components of the housing body 110 other than the exhaust valve 150. As a result, when the pressure inside the housing 100 reaches a predetermined value, the exhaust valve 150 breaks preferentially compared to other parts of the housing body 110, thereby venting the gas inside the housing 100 to the outside.

[0071] like Figure 2 As shown, a joining portion 115 is formed on the other of the pair of second side portions 112. The joining portion 115 extends along the width direction (X direction) of the secondary battery 1. In the joining portion 115, the end edges of the plate-shaped members constituting the housing body 110 are joined together.

[0072] like Figure 3As shown, an opening 113 (second opening) is provided at the end of the first side in the first direction (X direction) of the housing body 110. The opening 113 is sealed by a sealing plate 120 (second sealing plate). A joint portion 115 is formed in the opening 113 to seal the opening 113. The opening 113 and the sealing plate 120 have a generally rectangular shape in which the short side is in the Y direction and the long side is in the Z direction. The generally rectangular shape includes a rectangular shape or a shape that is substantially rectangular, such as a rectangular shape with chamfered corners.

[0073] A negative terminal 301 (second electrode terminal) is provided on the sealing plate 120. The position of the negative terminal 301 can be changed as appropriate.

[0074] like Figure 4 As shown, an opening 114 (first opening) is provided at the end of the housing body 110 on the side opposite to the first side in the X direction. That is, the opening 114 is located at the end opposite to the opening 113, and the openings 113 and 114 are opposite to each other. The opening 114 is sealed by a sealing plate 130 (first sealing plate). A joint 115 is formed in the opening 114 to seal it. The opening 114 and the sealing plate 130 have a generally rectangular shape with the short side in the Y direction and the long side in the Z direction.

[0075] A positive terminal 302 (first electrode terminal) and an injection hole 134 are provided on the sealing plate 130. The injection hole 134 is small enough to allow electrolyte to be injected into the housing 100, and preferably smaller than the insertion hole of the positive terminal 302 provided on the sealing plate 130. The injection hole 134 is preferably configured to be offset from the center of the sealing plate 130 in the Z direction. The positions of the positive terminal 302 and the injection hole 134 can be appropriately changed.

[0076] Sealing plates 120 and 130 are made of metal. Specifically, sealing plates 120 and 130 are made of aluminum, aluminum alloy, iron, or iron alloy.

[0077] The negative terminal 301 is electrically connected to the negative terminal (second electrode) of the electrode body 200. The negative terminal 301 is mounted on the sealing plate 120, i.e., the housing 100.

[0078] The positive terminal 302 is electrically connected to the positive terminal (first electrode) of the electrode body 200. The positive terminal 302 is mounted on the sealing plate 130, i.e. the housing 100.

[0079] The negative terminal 301 is made of a conductive material (more specifically, a metal), such as copper or a copper alloy. A portion or layer of aluminum or an aluminum alloy may also be provided on the outer surface of the negative terminal 301.

[0080] The positive terminal 302 is made of a conductive material (more specifically, a metal), such as aluminum or an aluminum alloy.

[0081] The injection port 134 is sealed by a sealing component (not shown). The sealing component can be, for example, a blind-hole rivet or other metal component.

[0082] Electrode body 200 is a flat electrode body formed by stacking negative and positive electrode plates, as described later. Specifically, electrode body 200 is a stacked electrode body in which multiple negative and positive electrode plates are alternately stacked via a separator. The separator can be formed by folding a strip-shaped insulating sheet component in a Z-shape, or by separately providing multiple insulating sheets. In this specification, "electrode body" is not limited to a stacked electrode body, and can also be a wound electrode body in which strip-shaped negative and positive electrode plates are wound together via a strip-shaped separator. The separator can be, for example, made of a polyolefin microporous membrane. When the electrode body is a stacked electrode body containing multiple negative electrode plates and multiple positive electrode plates, negative electrode tabs (second electrode tabs) disposed on each negative electrode plate can be stacked to form a negative electrode tab group (second electrode tab group), and positive electrode tabs (first electrode tabs) disposed on each positive electrode plate can be stacked to form a positive electrode tab group (first electrode tab group).

[0083] like Figure 6 As shown, the housing 100 accommodates the electrode body 200. Figure 6 In the following section, the first electrode body 201, which will be described later, will be illustrated. The first electrode body 201 is housed within the housing 100 with its long side direction parallel to the X direction.

[0084] Specifically, one or more stacked electrode bodies and an electrolyte (not shown) are housed together inside an insulating sheet 700 (described later) disposed within the housing 100. As the electrolyte (non-aqueous electrolyte), for example, an electrolyte prepared by dissolving LiPF6 at a concentration of 1.2 mol / L in a non-aqueous solvent composed of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC) in a volume ratio (25°C) of 30:30:40. A solid electrolyte may also be used instead of the electrolyte.

[0085] The electrode body 200 includes a first electrode body 201. The first electrode body 201 includes a generally rectangular main body, a negative electrode tab group 220, and a positive electrode tab group 250.

[0086] The main body is composed of a negative electrode plate 210 and a positive electrode plate 240, which will be described later. The negative electrode tab assembly 220 is located at the end (second end) of the first electrode body 201 in the X direction relative to the main body, on the side of the sealing plate 120. The positive electrode tab assembly 250 is located at the end (first end) of the first electrode body 201 in the X direction relative to the main body, on the other side (seal plate 130 side).

[0087] The negative electrode tab group 220 and the positive electrode tab group 250 are formed to protrude from the central portion of the electrode body 200 toward the sealing plate 120 or the sealing plate 130, respectively.

[0088] The current collector 400 includes a negative current collector 400A and a positive current collector 400B. The negative current collector 400A and the positive current collector 400B are each composed of plate-shaped components. The electrode body 200 is electrically connected to the negative terminal 301 and the positive terminal 302 via the current collector 400.

[0089] The negative current collector 400A is disposed on the sealing plate 120 via a resin insulating component. The negative current collector 400A is electrically connected to the negative electrode tab assembly 220 and the negative terminal 301. The negative current collector 400A is made of a conductive material (more specifically, a metal), such as copper or a copper alloy. Further details regarding the negative current collector 400A will be described later.

[0090] The positive current collector 400B is disposed on the sealing plate 130 via a resin insulating component. The positive current collector 400B is electrically connected to the positive electrode tab assembly 250 and the positive terminal 302. The positive current collector 400B is made of a conductive material (more specifically, a metal), such as aluminum or an aluminum alloy. Alternatively, the positive electrode tab assembly 250 can be electrically connected directly to the sealing plate 130, or electrically connected to the sealing plate 130 via the positive current collector 400B. In this case, the sealing plate 130 can also function as the positive terminal 302. Further details regarding the positive current collector 400B will be described later.

[0091] (Composition of electrode body 200)

[0092] like Figure 7 and Figure 8 As shown, a negative electrode tab 230, composed of a negative electrode core 211, is provided at one end of the negative electrode plate 210 in the width direction. When the negative electrode plates 210 are stacked, multiple negative electrode tabs 230 are stacked to form a negative electrode tab assembly 220. The negative electrode tab assembly 220 is electrically connected to the negative electrode. Considering the connection state between the negative electrode tab assembly 220 and the negative current collector 400A, the length of each negative electrode tab 230 in the protruding direction of the multiple negative electrode plates 210 is appropriately adjusted. The shape of the negative electrode tab 230 is not limited to... Figure 8 The illustrated shape.

[0093] like Figure 9 and Figure 10 As shown, a positive electrode tab 260, composed of a positive electrode core 241, is provided at one end of the positive electrode plate 240 in the width direction. When the positive electrode plates 240 are stacked, multiple positive electrode tabs 260 are stacked to form a positive electrode tab assembly 250. The positive electrode tab assembly 250 is electrically connected to the positive electrode. Considering the connection state between the positive electrode tab assembly 250 and the positive current collector 400B, the length of each positive electrode tab 260 in the protruding direction among the multiple positive electrode plates 240 is appropriately adjusted. The shape of the positive electrode tab 260 is not limited to... Figure 10 The illustrated shape.

[0094] A positive electrode protective layer 243 is provided at the root of the positive electrode tab 260. Alternatively, it may not be necessary to provide a positive electrode protective layer 243 at the root of the positive electrode tab 260.

[0095] 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 negative electrode tab group 220 is less than the thickness of the positive electrode tab group 250.

[0096] (Connection structure between electrode 200 and current collector 400)

[0097] Reference Figure 11 and Figure 12 The connection structure between the electrode body 200 and the current collector 400 will be explained.

[0098] like Figure 11 , Figure 12 As shown, the electrode body 200 includes a first electrode body 201 and a second electrode body 202. The first electrode body 201 and the second electrode body 202 respectively include a positive electrode and a negative electrode. The electrode body 200 may also be composed of three or more electrode bodies.

[0099] The electrode body 200 is formed by overlapping a first electrode body 201 and a second electrode body 202. The first electrode body 201 and the second electrode body 202 are arranged in the thickness direction (Y direction) of the first electrode body 201 and the second electrode body 202.

[0100] like Figure 11 (As shown in the connection structure on the negative electrode side), the first electrode body 201 includes a negative electrode tab assembly 220. The negative electrode tab assembly 220 is electrically connected to the current collector 410 (negative current collector) at its first end 205 in the X direction. The second electrode body 202 includes a negative electrode tab assembly 270. The negative electrode tab assembly 270 is electrically connected to the current collector 410 (negative current collector) at its third end 207 in the X direction.

[0101] The negative electrode tab assembly 220 has a bent portion 221 and a front end portion 222. The bent portion 221 is the bent part of the negative electrode tab assembly 220. The front end portion 222 is the part located at the end of the negative electrode tab assembly 220.

[0102] The negative electrode tab assembly 270 has a bent portion 271 and a front end portion 272. The bent portion 271 is the bent part of the negative electrode tab assembly 270. The front end portion 272 is the part located at the end of the negative electrode tab assembly 270.

[0103] Negative electrode tab group 220 and negative electrode tab group 270 are each bent in opposite directions with their front ends 222 and 272 approaching each other. In this embodiment, the front ends 222 and 272 are separated, but this structure is not limited to this; the front ends 222 and 272 may also be in contact with each other.

[0104] The negative current collector 400A electrically connects the negative terminal 301 to the negative electrode tab group 220 and the negative electrode tab group 270. In this embodiment, the negative current collector 400A is connected to the negative terminal 301 between the electrode body 200 and the sealing plate 120. The negative current collector 400A includes a current collector 410 and a current collector 430.

[0105] Current collector 410 is a plate-shaped component. Current collector 410 has a long side in the Z-direction and a short side in the Y-direction. Current collector 410 is composed of a single, integral component. Current collector 430 is a plate-shaped component. Current collector 430 has a long side in the Z-direction and a short side in the Y-direction. Current collectors 410 and 430 are arranged side-by-side in the X-direction. Thus, current collectors 410 and 430 are composed of separate, independent components.

[0106] Negative electrode tabs 220 and 270 are described later (see reference). Figure 15 The joint portion 411 is joined to the current collector 410. The joint portion 411 can be formed, for example, by laser welding.

[0107] The current collector 430 is joined to the current collector 410 at its Z-direction end. The current collector 430 is connected to the negative terminal 301. The connection between the current collector 430 and the negative terminal 301 can be formed, for example, by riveting and / or welding.

[0108] The negative terminal 301 is exposed on the outside of the sealing plate 120. The negative terminal 301 is connected to the plate-shaped component 303. The negative terminal 301 preferably includes a region 301A made of copper or copper alloy and a region 301B made of aluminum or aluminum alloy, and the region 301A made of copper or copper alloy is connected to the current collector 430.

[0109] The plate-shaped component 303 is located on the outside of the sealing plate 120. The plate-shaped component 303 is arranged along the sealing plate 120. The plate-shaped component 303 is conductive. The plate-shaped component 303 is arranged to ensure the connection area, etc., with the busbar that electrically connects the secondary battery 1 to other adjacent secondary batteries. The connection between the negative terminal 301 and the plate-shaped component 303 can be formed, for example, by laser welding.

[0110] An insulating component 510 is disposed between the plate-shaped component 303 and the sealing plate 120. An insulating component 520 is disposed between the negative terminal 301 and the sealing plate 120. An insulating component 530 is disposed between the current collector 430 and the sealing plate 120.

[0111] However, the negative terminal 301 can also be electrically connected to the sealing plate 120. The sealing plate 120 can also function as the negative terminal 301.

[0112] An insulating member 600 is disposed between the sealing plate 120 and the main body of the electrode body 200 (excluding the negative electrode tabs 220 and 270). The insulating member 600 is made of an insulating resin component. The insulating member 600 suppresses the movement of the electrode body 200 in the X direction within the housing 100 and suppresses damage to the negative electrode tabs 220, the negative electrode tabs 270, and the electrode body 200.

[0113] like Figure 12 (Connection structure on the positive side) As shown, the connection structure between the electrode body 200 and the current collector 400 on the positive side differs from that on the negative side in that the part corresponding to the current collector 410 on the negative side is composed of two components.

[0114] The first electrode 201 includes a positive electrode tab assembly 250. The positive electrode tab assembly 250 is electrically connected to the current collector 420 (positive current collector) at its second end 206 in the X direction. The second electrode 202 includes a positive electrode tab assembly 280. The positive electrode tab assembly 280 is electrically connected to the current collector 420 at its fourth end 208 in the X direction.

[0115] The positive electrode tab assembly 250 has a bent portion 251 and a front end portion 252. The bent portion 251 is the bent part of the positive electrode tab assembly 250. The front end portion 252 is the part located at the end of the positive electrode tab assembly 250.

[0116] The positive electrode tab assembly 280 has a bent portion 281 and a front end portion 282. The bent portion 281 is the bent part of the positive electrode tab assembly 280. The front end portion 282 is the part located at the end of the positive electrode tab assembly 280.

[0117] The positive electrode tab group 250 and the positive electrode tab group 280 are each bent in opposite directions with their front ends 252 and 282 approaching each other. In this embodiment, the front ends 252 and 282 are separated, but this structure is not limited to this; the front ends 252 and 282 may also be in contact with each other.

[0118] The positive current collector 400B electrically connects the positive terminal 302 to the positive electrode tab group 250 and the positive electrode tab group 280. In this embodiment, the positive current collector 400B is connected to the positive terminal 302 between the electrode body 200 and the sealing plate 130.

[0119] The positive current collector 400B includes a current collector 420 and a current collector 440. An insulating member 460 is sandwiched between the current collector 420 and the current collector 440, but is electrically connected at a location different from the cross-section shown in the figure.

[0120] The current collector 420 is a plate-shaped component. The current collector 420 has a long side in the Z direction and a short side in the Y direction. The current collector 420 consists of one current collector and other current collectors. That is, the current collector 420 is composed of two components.

[0121] Positive electrode tab assembly 250 and positive electrode tab assembly 280 are joined at the following location 421 (see reference). Figure 15 It is joined to a current collector 420 consisting of two components. The joining part 421 can be formed, for example, by laser welding.

[0122] The current collector 440 is joined to the current collector 420 at its Z-direction end. The current collector 440 is connected to the positive terminal 302. The connection between the current collector 440 and the positive terminal 302 can be formed, for example, by riveting and / or welding.

[0123] The positive terminal 302 is configured to protrude from the outside of the sealing plate 130 and reach the current collector 440 of the positive current collector 400B disposed on the inner surface side of the sealing plate 130. The positive terminal 302 is connected to the plate-shaped component 304.

[0124] The plate-shaped component 304 is located on the outside of the sealing plate 130. The plate-shaped component 304 is arranged along the sealing plate 130. The plate-shaped component 304 is conductive. The plate-shaped component 304 is arranged to ensure the connection area, etc., with the busbar that electrically connects the secondary battery 1 to other adjacent secondary batteries. The connection between the positive terminal 302 and the plate-shaped component 304 can be formed, for example, by laser welding.

[0125] An insulating component 510 is disposed between the plate-shaped component 304 and the sealing plate 130. An insulating component 520 is disposed between the positive terminal 302 and the sealing plate 130. An insulating component 470 is disposed between the current collector 440 and the sealing plate 130.

[0126] However, the positive terminal 302 can also be electrically connected to the sealing plate 130. The sealing plate 130 can also function as the positive terminal 302.

[0127] An insulating member 600 is disposed between the sealing plate 130 and the main body of the electrode body 200 (excluding the positive electrode tabs 250 and 280). The insulating member 600 is made of an insulating resin component. The insulating member 600 suppresses the movement of the electrode body 200 in the X direction within the housing 100 and suppresses damage to the positive electrode tabs 250 and 280 and the electrode body 200.

[0128] Figure 11 and Figure 12 The isolation element 600 shown is, for example, made of resin. The material of the isolation element 600 is, for example, polypropylene (PP), polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), or ethylene propylene diene rubber (EPDM).

[0129] like Figure 11 and Figure 12 As shown, a resin insulating sheet 700 (electrode holder) is disposed between the electrode body 200 and the housing body 110. The insulating sheet 700 may be made of resin, for example. More specifically, the insulating sheet 700 may be made of polypropylene (PP), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyimide (PI), or polyolefin (PO).

[0130] (Manufacturing process of secondary battery 1)

[0131] The following uses Figure 13 The flowchart below describes the manufacturing method of the secondary battery according to this embodiment. In the manufacturing method of the secondary battery according to this embodiment, firstly, a first electrode body 201 and a second electrode body 202 are manufactured (S1 step). It is preferable that a portion of the front end of each of the negative electrode tab group 220, positive electrode tab group 250, negative electrode tab group 270 and positive electrode tab group 280 is cut off so that the length of the front end is the same when they are bundled.

[0132] like Figure 14 and Figure 15 As shown, after the first electrode body 201 and the second electrode body 202 are manufactured, the positive electrode tabs 250 and 280 are joined to the current collector 420 (S2 process). The positive electrode tabs 250 and 280 are joined to the current collector 420 at the joining portion 421.

[0133] Next, the first electrode 201, the current collector 410, and the second electrode 202 are arranged sequentially in the DR1 direction. A negative electrode tab assembly 220 is positioned on one side of the current collector 410 in the DR1 direction. With the negative electrode tab assembly 270 positioned on the other side of the current collector 410 in the DR1 direction, the negative electrode tab assembly 220 and the negative electrode tab assembly 270 are joined to the current collector 410 (step S3). The negative electrode tab assembly 220 and the negative electrode tab assembly 270 are joined to the current collector 410 at the joining portion 411.

[0134] In the height direction of the first electrode 201 and the second electrode 202, the current collectors 410 and 420 are offset to one side relative to the center of the first electrode 201 and the second electrode 202. Therefore, since the current collectors can be made shorter, they can be made smaller. The current collectors 410 and 420 are not limited to this structure. The current collectors 410 and 420 may also be arranged at the center of the first electrode 201 and the second electrode 202 in the height direction.

[0135] The order in which current collector 410 and current collector 420 are joined relative to the first electrode 201 and the second electrode 202, respectively, is not limited to the above-described order and may be changed. Preferably, the process of joining current collector 420 relative to the first electrode 201 and the second electrode 202 is performed before the process of overlapping the first electrode 201 and the second electrode 202, which will be described later, and preferably before the process of joining current collector 410 relative to the first electrode 201 and the second electrode 202.

[0136] Next, after joining the negative electrode tab group 220 and the negative electrode tab group 270 to the current collector 410, in the thickness direction of the first electrode body 201 and the second electrode body 202 ( Figure 17 and Figure 18 In a direction orthogonal to DR1, the negative electrode tab group 220 and the negative electrode tab group 270 are bent so that the first electrode body 201 and the second electrode body 202 overlap (S4 process). That is, the first electrode body 201 and the second electrode body 202 are integrated together.

[0137] The phrase "overlapping the first electrode and the second electrode" can mean that the first electrode and the second electrode can be directly overlapped, or other components can be placed between the first electrode and the second electrode. The first electrode and the second electrode can be fixed with tape or the like, or they can be left unfixed. Furthermore, the first electrode, the current collector, and the second electrode can not be arranged in a straight line in the DR1 direction, and the first electrode or the second electrode can be tilted relative to the current collector in the DR1 direction.

[0138] Negative electrode tabs 220 and 270 are bent so that their front ends face each other. Positive electrode tabs 250 and 280 are also bent so that their front ends face each other.

[0139] Next, as Figure 16 As shown, the separator 600 and the insulating sheet 700 are assembled onto the electrode body 200 (step S5). After assembling the separator 600 onto the negative and positive sides of the electrode body 200 respectively, the electrode body 200 and the separators 600 on both sides are covered by the insulating sheet 700. Thus, with the separators 600 positioned on both sides of the electrode body 200, the electrode body 200 and the separators 600 on both sides are covered by the insulating sheet 700. The insulating sheet 700 is fixed to the separators 600 on both sides.

[0140] Next, as Figure 17 and Figure 18 As shown, current collector 410 is electrically connected to negative terminal 301 via current collector 430 (step S6). Step S6 can also be performed before step S5. Specifically, as shown... Figure 18 As shown, the negative electrode tab group 220 and the negative electrode tab group 270 are bent so that the front ends 222 and 272 face each other.

[0141] The negative terminal 301 and the current collector 430 are mounted on the sealing plate 120 via an insulating component. The current collector 430 and the current collector 410 are brought into contact in the X direction. The plate-shaped component 303 can be connected to the negative terminal 301 at any time. The current collector 430 and the current collector 410 are joined by laser welding between the sealing plate 120 and the insulating sheet 700.

[0142] Next, with the current collector 420 side as the front, the isolator 600 and the electrode 200 are inserted into the housing body 110 through the opening 113 (step S7). In this embodiment, after the insulating member 460 is installed on the two current collectors 420, the electrode 200 is inserted into the housing body 110. In this way, the electrode 200 can be inserted into the housing body 110 while the two current collectors 420 are combined into one.

[0143] After the electrode body 200 is inserted into the housing body 110, the sealing plate 120 is brought close to the main body of the electrode body 200 (the first electrode body 201 and the second electrode body 202), causing the negative electrode tab group 220 and the negative electrode tab group 270 to bend from the state of extending from the negative electrode tab group 220 and the negative electrode tab group 270. Figure 11 (As shown in the diagram). The negative electrode tab assembly 220 and the negative electrode tab assembly 270 are bent along the shape of the separator 600 in such a way that the folded-back portions of the bends 221 and 271 approach the housing body 110 in the Y direction.

[0144] like Figure 19 As shown, after the sealing plate 120 abuts against the housing body 110, the sealing plate 120 is temporarily joined to the housing body 110. Through this temporary joining, the sealing plate 120 is partially joined to the opening 113 of the housing body 110. Thus, the sealing plate 120 is positioned relative to the housing body 110.

[0145] When the electrode body 200 is inserted into the housing body 110, the electrode body 200 can be pulled from the current collector 420 side or pressed from the current collector 410 side. When the electrode body 200 is pressed from the current collector 410 side, both the negative electrode tab group 220 and the negative electrode tab group 270 can be bent simultaneously.

[0146] After inserting the electrode body 200 into the housing body 110, the current collector 420 is electrically connected to the positive terminal 302 (step S8). Specifically, the positive terminal 302 is mounted to the sealing plate 130 via an insulating member. After inserting the first electrode body 201 and the second electrode body 202 into the housing body 110, the current collector 440 abuts against the current collector 420 protruding from the opening 114 in the X direction. The plate-shaped member 304 can be connected to the positive terminal 302 at any time.

[0147] The positive electrode tab group 250 (first tab group) and the positive electrode tab group 280 (second tab group) connected to the current collector 420 are bent so that their front ends 252 and 282 are opposite to each other. Figure 12 As shown, the positive electrode tabs 250 and 280 are bent along the shape of the separator 600 such that the folded-back portions of the bends 251 and 281 approach the housing body 110 in the Y direction.

[0148] After inserting the separator 600 and the electrode body 200 into the housing body 110, the sealing plate 130 and the sealing plate 120 are joined to the housing body 110 (S9 process).

[0149] like Figure 20 As shown, after the sealing plate 130 abuts against the housing body 110, the sealing plate 130 is temporarily welded to the housing body 110. Through this temporary connection, the sealing plate 130 is partially joined to the opening 114 of the housing body 110. Thus, the sealing plate 130 is positioned relative to the housing body 110.

[0150] Next, sealing plate 120 and sealing plate 130 are joined to housing body 110. Sealing plate 120 seals opening 113 of housing body 110, and sealing plate 130 seals opening 114 of housing body 110. Thus, housing 100 houses first electrode body 201 and second electrode body 202.

[0151] After the above-mentioned processes, leak checks and other inspections are performed (S10 process). After the leak check, the secondary battery 1 is dried in order to remove moisture from the casing 100.

[0152] Next, with the sealing plate 130 positioned vertically above the sealing plate 120 and the separator 600 positioned below the electrode body 200, electrolyte is injected into the housing 100 through the injection hole 134 provided in the sealing plate 130 (step S11). Since the separator 600 is provided around the electrolyte injection point, damage to the electrode body 200 and the like can be suppressed even when electrolyte is rapidly injected into the housing 100. Therefore, for the secondary battery 1 of this embodiment, electrolyte can be injected in a shorter time compared to the case where the separator 600 is not provided. Afterwards, venting and charging are performed. During venting and charging, the injection hole 134 can also be temporarily sealed. Afterwards, the injection hole 134 is sealed, and the secondary battery 1 is completed.

[0153] (Connection between insulating component 460 and current collector 420)

[0154] like Figures 21-25 As shown, two current collectors 420 (first conductive components) are connected to one insulating component 460. The two current collectors 420 (first component and second component) are engaged with positive electrode tabs 250 and 280 (first electrode tab and second electrode tab). However, the scope of this technology is not limited to this, and one current collector 420 may also be connected to one insulating component 460.

[0155] Preferably, the two current collectors 420 have the same shape. Preferably, the two current collectors 420 are arranged separately from each other. However, the two current collectors 420 may also be in contact with each other.

[0156] The current collector 420 is a plate-shaped component having a long side in the Z-axis direction and a short side in the Y-axis direction. The current collector 420 is made of metal, such as preferably aluminum or an aluminum alloy.

[0157] The current collector 420 includes a through hole 420A (first through hole), a through hole 420B (second through hole), recesses 420C1 and 420C2, a fuse portion 420D, and a plate-shaped portion 420E (first plate-shaped portion).

[0158] Insulating member 460 includes convex portion 460A (first convex portion), convex portion 460B (second convex portion), convex portion 460C (third convex portion), and plate-shaped portion 460D (second plate-shaped portion).

[0159] The plate-shaped portion 420E of the current collector 420 is arranged to overlap with the plate-shaped portion 460D of the insulating member 460. The protrusion 460A of the insulating member 460 is disposed within the through hole 420A of the current collector 420. Thus, the current collector 420 and the insulating member 460 are fixed or connected to each other.

[0160] The through hole 420A of the current collector 420 is used for the connection between the current collector 420 and the insulating member 460. Furthermore, it is preferable that there is no gap between the shaft portion 460A1 and the inner wall of the through hole 420A. Alternatively, it is preferable that the gap between the shaft portion 460A1 and the inner wall of the through hole 420A is as small as possible. When a gap exists between the shaft portion 460A1 and the inner wall of the through hole 420A, it is preferably less than 0.5 mm, more preferably less than 0.3 mm, and even more preferably less than 0.2 mm.

[0161] When joining current collector 420 and current collector 440, it is preferable to align current collector 420 and current collector 440 with each other in the Z direction. This allows for a stable joining of current collector 420 and current collector 440, thereby increasing the reliability of the joint.

[0162] Furthermore, the shape of the through hole 420A is not limited to a perfect circle; it can be an ellipse, an oblong shape, or a polygon such as a roughly square or roughly rectangular shape. Additionally, the corners of the polygon can be chamfered. When the through hole 420A has a major axis direction or a long side direction, it is preferable that the major axis direction or long side direction is along the direction in which the protrusions 460A and 460B are arranged (Z direction). Moreover, it is particularly preferred that the shape of the through hole 420A is a perfect circle or a shape close to it (e.g., a circle with a minor axis / major axis ratio of 0.8 to 1.0).

[0163] The relationship between the protrusion 460B and the through hole 420B can be set such that, at least in the width direction (Y direction) of the current collector 420, a larger positional offset is allowed compared to the relationship between the protrusion 460A and the through hole 420A. In this case, the clearance between the protrusion 460B and the through hole 420B is greater than the clearance between the protrusion 460A and the through hole 420A. The protrusion 460B and the through hole 420B can function as guides when mounting the current collector 420 onto the insulating member 460. Furthermore, the protrusion 460B and the through hole 420B can suppress large positional offsets of the current collector 420 relative to the insulating member 460. Moreover, it is preferable that the protrusion height of the protrusion 460B is higher than the protrusion height of the protrusion 460A. Therefore, the function of the protrusion 460B as a guide is improved.

[0164] Furthermore, the gap between the protrusion 460B and the inner wall of the through hole 420B (the largest gap) is preferably 0.3 mm or more, more preferably 0.5 mm or more, and even more preferably 1 mm or more. Additionally, the largest gap between the protrusion 460B and the inner wall of the through hole 420B is preferably located in the Z direction.

[0165] Furthermore, the shape of the through hole 420B is not limited to an oblong shape; it can also be a circle, an ellipse, or a polygon such as a roughly square or roughly rectangular shape. Additionally, the corners of the polygon can be chamfered. When the through hole 420B has a major axis direction or a long side direction, it is preferable that the major axis direction or long side direction is along the direction in which the protrusions 460A and 460B are arranged (Z direction).

[0166] However, it is also possible to provide a through hole 420A in place of a through hole 420B in the current collector 420, and to provide a protrusion 460A in place of a protrusion 460B in the insulating member 460, and to insert the protrusion 460A into the through hole 420A. In this case, the current collector 420 and the insulating member 460 can be fixed or connected at two locations, thus achieving a more stable mutual retention.

[0167] Recesses 420C1 and 420C2 are cut-out portions (necked portions) at the ends of the current collector 420 in the width direction (Y direction). Furthermore, recesses 420C1 and 420C2 can be positioned approximately at the same location in the length direction (Z direction) of the current collector 420. Recesses 420C1 and 420C2 are formed with different shapes. Therefore, recesses 420C1 and 420C2 can provide visual orientation determination (suppressing errors in orientation).

[0168] The fuse section 420D is formed by reducing the cross-sectional area of ​​the current collector 420. Besides the through-hole shape illustrated in this embodiment, the fuse section 420D can also be composed of a cut-out portion, a thin-walled portion, or the like. When a current exceeding a predetermined value flows, the fuse section 420D can melt to cut off the conductive path. Furthermore, in the width direction (Y direction) of the current collector 420, it is preferable that the length of the through-hole in the fuse section 420D is greater than the length of the through-hole 420A.

[0169] Preferably, the insulating component 460 is made of resin. For example, resins such as polypropylene (PP), perfluoroalkoxy alkane (PFA), fluorinated ethylene propylene (FEP), polyphenylene sulfide (PPS), and ethylene propylene diene monomer (EPDM) can be used.

[0170] like Figure 24 As shown, the protrusion 460A of the insulating member 460 has a pair of shaft portions 460A1 (first part) and a pair of expanded diameter portions 460A2 (second part). A slit is provided between the pair of shaft portions 460A1. The pair of shaft portions 460A1 are inserted into the through hole 420A of the current collector 420. The pair of expanded diameter portions 460A2 are provided at the respective front ends of the pair of shaft portions 460A1. The outer diameter of the pair of expanded diameter portions 460A2 together (including the slit between the pair of expanded diameter portions 460A2) is larger than the outer diameter of the pair of shaft portions 460A1 together. When the shaft portion 460A1 is inserted into the through hole 420A, the shaft portion 460A1 is deformed in a radially inward tilt. As a result, the expanded diameter portion 460A2 can pass through the through hole 420A. The front end (expanded diameter portion 460A2) of the preferred protrusion 460A has a curved surface shape that can be guided to the through hole 420A.

[0171] A through hole 460A3 is formed at the root of the shaft portion 460A1. The through hole 460A3 is formed in the region including the enlarged diameter portion 460A2 when viewed from the X direction. As a result, the insulating component 460 can be easily integrally formed.

[0172] like Figure 26As shown, in the protrusion 460A, the enlarged diameter portion 460A2, which is a portion protruding outward (to the -X side) from the through hole 420A, protrudes further outward in the radial direction of the through hole 420A compared to the edge portion of the through hole 420A. Furthermore, in the enlarged diameter portion 460A2, the surface on the shaft portion 460A1 side (to the +X side) faces (preferably abuts against) the outer surface of the current collector 420 in the thickness direction. With this configuration, the current collector 420 and the insulating member 460 can be more securely fixed or connected using the protrusion 460A.

[0173] like Figure 27 As shown, in the protrusion 460B, the outer diameter of the portion protruding outward (to the -X side) from the through hole 420B is smaller than the inner diameter of the through hole 420B. That is, in the protrusion 460B, the portion protruding from the through hole 420B does not protrude outward in the radial direction of the through hole 420B compared to the edge portion of the through hole 420B. Furthermore, a gap is formed between the protrusion 460B and the inner wall of the through hole 420B that is larger than the gap between the protrusion 460A and the inner wall of the through hole 420A. This effectively suppresses the decrease in assemblability when assembling the insulating member 460 to the current collector 420.

[0174] After the shaft portion 460A1 is inserted through the through hole 420A and its shape is restored, the enlarged diameter portion 460A2 is disposed on the outside of the through hole 420A, serving as a fixing portion for the current collector 420 and the insulating member 460. At this time, the enlarged diameter portion 460A2 abuts against the outer surface of the current collector 420, or faces the outer surface of the current collector 420 with a slight gap in the thickness direction of the current collector 420. The width of this gap (in the thickness direction of the current collector 420) is preferably 0.5 mm or less, more preferably 0.3 mm or less, and even more preferably 0.1 mm or less.

[0175] A protrusion 460A is formed on the upper end (one side end) of the current collector 420, and a protrusion 460B is formed on the lower end (the other side end) of the current collector 420. Preferably, the protrusion 460A is located closer to the welding portion (joint portion 800 described later) between the current collector 420 and the current collector 440 than the protrusion 460B.

[0176] For example, the preferred protrusion 460A is positioned closer to the welded portion (joint portion 800 described later) between the current collector 420 and the current collector 440 than the portion in the current collector 420 that joins the positive electrode tabs 250 and 280. Furthermore, the distance in the Z direction from the upper end (the +Z side end) of the joint portion 800 to the center of the protrusion 460A is preferably 20 mm or less, more preferably 15 mm or less, and even more preferably 10 mm or less.

[0177] By fixing or connecting the current collector 420 to the insulating member 460 near the joint 800, the current collectors 420 and 440 can be stably aligned with each other during the jointing of the current collectors 420 and 440, thereby improving the reliability of the joint 800.

[0178] The form of the protrusion 460A is not limited to the examples described above. For example, the protrusion 460A is not limited to being divided into two parts; it can also be a single protrusion, consisting of a shaft portion and an enlarged diameter portion. Alternatively, the protrusion 460A can be pressed into the through hole 420A of the current collector 420. Furthermore, after inserting the protrusion 460A into the through hole 420A, the enlarged diameter portion 460A2 can be formed by deforming the protrusion 460A through methods such as thermal riveting.

[0179] For the protrusion 460C, a portion of it is disposed within a recess 420C1 of one current collector 420, and another portion is disposed within a recess 420C2 of another current collector 420. Preferably, the protrusion height of the protrusion 460C is lower than the protrusion height of the protrusions 460A and 460B. Furthermore, it is preferable that the protrusion height of the protrusion 460C is less than the thickness of the current collector 420.

[0180] In the secondary battery 1 according to this embodiment, by connecting the current collector 420, which is connected to the positive electrode tabs 250 and 280, to the insulating member 460, it is possible to suppress unexpected deformation of the positive electrode tabs 250 and 280 when the electrode body 200 is inserted into the housing body 110 with the positive electrode tabs 250 and 280 side as the front end. Therefore, damage to the positive electrode tabs 250 and 280 can be suppressed. Thus, a highly reliable secondary battery 1 is achieved.

[0181] Furthermore, the positional relationship between the current collector 420 and the current collector 440 can be stabilized via the insulating member 460, thereby improving the reliability of the engagement between the current collector 420 and the current collector 440 after the electrode body 200 is inserted into the housing body 110. As a result, a secondary battery 1 with higher reliability is obtained.

[0182] (The current collector 440 is positioned on the insulating component 470)

[0183] like Figures 28-30 As shown, the insulating component 470 and the current collector 440 (the second conductive component) have a long side direction in the Z-axis direction and a short side direction in the Y-axis direction.

[0184] The insulating component 470 includes a base portion 470A and a through hole 470B. The base portion 470A is formed in the shape of a plate and is disposed along the sealing plate 130. Therefore, when the insulating component 470 is mounted on the sealing plate 130, the base portion 470A extends along the YZ plane. The base portion 470A is disposed between the current collector 440 and the sealing plate 130. A positive terminal 302 is inserted through the through hole 470B.

[0185] The current collector 440 is a plate-shaped component having a through hole 440A and a protrusion 440B. The current collector 440 is made of metal, preferably aluminum or an aluminum alloy. The current collector 440 is disposed on the insulating component 470. The through hole 440A of the current collector 440 communicates with the through hole 470B of the insulating component 470. A positive terminal 302 is inserted through the through hole 440A. The protrusion 440B of the current collector 440 engages with a recess or hole (not shown) formed in the insulating component 460, which facilitates the alignment of the current collector 440 with the insulating component 460.

[0186] (Current collector structure on the positive side)

[0187] like Figure 31 As shown, the insulating component 460 connected to the current collector 420 and the current collector 440, which is mounted on the sealing plate 130 together with the insulating component 470, overlap. At this time, the current collector 420 and the current collector 440 abut against each other at their upper ends. The insulating component 470 is disposed between the sealing plate 130 and the current collector 440.

[0188] At least one of the current collectors 420 and 440 (in Figure 31 In the example, a stepped portion is formed for the current collector 420. This creates a tapered gap S1 between the current collectors 420 and 440. The gap S1 gradually decreases in size towards the upper side of the current collectors 420 and 440. The gap S1 has an area where no insulating member 460 is disposed. By providing the gap S1, the escape of heat generated during the formation of the junction of the current collectors 420 and 440 to the lower side of the current collectors 420 and 440 can be suppressed. Therefore, the junction of the current collectors 420 and 440 can be formed stably, and the heat transferred to the positive electrode tabs 250 and 280, the electrode body 200, and other conductive components can be reduced.

[0189] like Figure 32 , Figure 33As shown, by irradiating the upper end (first end) of current collector 420 and the upper end (second end) of current collector 440 with energy line 2, a joint 800 (welding portion) is formed to join current collectors 420 and 440. This electrically connects current collector 420 to the positive terminal 302. It is preferable to join current collectors 420 and 440 by welding. More preferably, for example, current collectors 420 and 440 are joined by laser welding. It is preferable to irradiate the energy line 2 between the housing body 110 and the sealing plate 130.

[0190] In this embodiment, the joint 800 is formed at the +Z side end of the current collectors 420 and 440, but the location where the joint 800 is formed is not limited to this. Figure 33 As shown, preferably, the center (deepest part) of the joint 800 coincides with the boundary of the current collectors 420 and 440. However, the center of the joint 800 may also be located at... Figure 33 The state shown is slightly offset toward either the collector 420 side (-X side) or the collector 440 side (+X side).

[0191] When the sealing plate 130 is assembled to the housing body 110, the joint portion 800 is pressed into the housing body 110. After the sealing plate 130 is assembled to the housing body 110, the joint portion 800 faces the inner surface (second side portion 112B) of the housing body 110.

[0192] In the secondary battery 1 according to this embodiment, an energy line 2 is irradiated onto the current collectors 420 and 440 from the outside of the housing body 110 to form a joint 800, and then the joint 800 is pressed into the interior of the housing body 110. In this way, the generation of foreign matter and damage to the insulating components can be suppressed, and a secondary battery 1 with high energy density can be obtained.

[0193] like Figure 31 As shown, in the positive electrode current collector structure, the current collector 420 protrudes further downward (to the side opposite to the junction 800) than the insulating member 460. Furthermore, the insulating member 460 protrudes further downward (to the side opposite to the junction 800) than the current collector 440.

[0194] Since the current collector 420 protrudes further downward than the insulating component 460, during the joining process of the current collectors 420 and 440, a clamp for alignment is provided at the upper end of the current collectors 420 and 440, and the current collector 420 is lifted from below, thereby facilitating the alignment of the current collectors 420 and 440 in the height direction (Z direction). This improves the reliability of the joint 800 of the current collectors 420 and 440.

[0195] In addition, since the insulating component 460 protrudes further downward than the current collector 440, it can reliably ensure the insulation between the current collectors 420 and 440.

[0196] (Dimensional relationship between through hole 420B and protrusion 460B)

[0197] The fitting gap between the through hole 420B and the protrusion 460B is preferably 0.3 mm or more, and more preferably 1 mm or more.

[0198] In the Z direction (the direction with the largest inner diameter of the through hole 420B), the inner diameter of the through hole 420B ( Figure 34 :A1) and the outer diameter of the convex part 460B ( Figure 34 The ratio of A2 / A1 is preferably 0.9 or less, more preferably 0.8 or less, and even more preferably 0.7 or less. Furthermore, it is preferable that A2 / A1 is 0.2 or more.

[0199] In the Y direction (the direction with the smallest inner diameter of the through hole 420B), the inner diameter of the through hole 420B ( Figure 34 :B1) and the outer diameter of the convex part 460B ( Figure 34 The relationship between B2 and B1 is preferably B2 / B1 being 0.9 or less, more preferably B2 / B1 being 0.8 or less, and even more preferably B2 / B1 being 0.7 or less. Furthermore, it is preferable that B2 / B1 is 0.2 or more.

[0200] (Modified example)

[0201] In this technology, the connection method between the current collector 420 and the insulating component 460 is not limited to the methods described above. For example, in Figure 35 In the modified example shown, the insulating member 460 has a shaft portion 460E protruding from the plate-shaped portion 460D, and a claw portion 460F disposed at the front end of the shaft portion 460E. The claw portion 460F faces the outer surface of the current collector 420. Figure 35 In the example, it engages with the current collector 420. This connects or secures the current collector 420 to the insulating component 460. However, a small gap may exist between the claw 460F and the current collector 420.

[0202] Preferably, the claw portion 460F is disposed on both sides of the current collector 420 in the Y direction. This enables a stable connection between the current collector 420 and the insulating component 460.

[0203] Embodiments of the present invention have been described; however, all points of the embodiments disclosed herein should be considered illustrative and not intended to limit the invention. The scope of the invention is defined by the technical solutions and is intended to include equivalents and all modifications within that scope.

Claims

1. An energy storage device, characterized in that, have: An electrode body includes a first electrode, a second electrode with a polarity different from that of the first electrode, and a first electrode tab assembly electrically connected to the first electrode; A housing that accommodates the electrode body; The first conductive component is connected to the first electrode tab assembly; A second conductive component, which is connected to the first conductive component; and An insulating component is disposed between the first conductive component and the second conductive component. The first electrode tab assembly is located at one end of the electrode body. The insulating component is connected to the first conductive component.

2. The energy storage device according to claim 1, characterized in that, The first conductive component includes a first plate-shaped portion. The insulating component includes a second plate-shaped portion. The first plate-shaped portion of the first conductive component is arranged to overlap with the second plate-shaped portion of the insulating component.

3. The energy storage device according to claim 1 or 2, characterized in that, The first conductive component has a first end. The second conductive component has a second end adjacent to the first end. Welding portions are formed at the first end and the second end to join the first conductive component and the second conductive component.

4. The energy storage device according to claim 1 or 2, characterized in that, The first conductive component has a first through hole. The insulating component has a first protrusion. By placing the first protrusion inside the first through hole, a fixing part is formed to fix the first conductive component and the insulating component to each other.

5. The energy storage device according to claim 4, characterized in that, The first conductive component has a second through hole. The insulating component has a second protrusion. The second protrusion is disposed within the second through hole in such a way that a gap is formed between the outer surface of the second protrusion and the inner surface of the second through hole.

6. The energy storage device according to claim 4, characterized in that, The first conductive component has an outer surface located on the side opposite to the insulating component. The first protrusion has a first portion disposed within the first through hole, and a second portion having an outer diameter larger than that of the first portion and disposed at a position closer to the front end of the first protrusion than the first portion. The second part is disposed outside the first through hole of the first conductive component. The second portion of the first protrusion abuts against the outer surface of the first conductive component, or the second portion of the first protrusion faces the outer surface of the first conductive component with a gap of less than 0.5 mm.

7. The energy storage device according to claim 4, characterized in that, The device is provided with multiple fixing parts.

8. The energy storage device according to claim 1 or 2, characterized in that, The first conductive component has a first end, a first through hole, and a second through hole. The second conductive component has a first protrusion, a second protrusion, and a second end adjacent to the first end. Welding portions are formed at the first end and the second end to join the first conductive component and the second conductive component. By placing the first protrusion within the first through hole, a fixing portion is formed that secures the first conductive component and the insulating component to each other. The second protrusion is disposed within the second through hole in such a manner that a gap is formed between the outer surface of the second protrusion and the inner surface of the second through hole. The first through hole is positioned closer to the welded portion than the second through hole.

9. The energy storage device according to claim 1 or 2, characterized in that, A joint portion between the first conductive component and the second conductive component is provided at the end side of one of the first conductive component and the second conductive component. The first conductive component protrudes to the side opposite to the joint portion compared to the insulating component. The insulating component protrudes to the side opposite to the joint portion than the second conductive component.

10. The energy storage device according to claim 1 or 2, characterized in that, The first conductive component has an outer surface located on the side opposite to the insulating component. The insulating component has claws facing the outer surface of the first conductive component. The claw portion forms a fixing part that fixes the first conductive component and the insulating component to each other.

11. The energy storage device according to claim 1 or 2, characterized in that, The first electrode tab group includes a separately formed first electrode tab group and a second electrode tab group. The first conductive component includes a first component and a second component, which are set as independent components. The first component engages with the first electrode assembly, and the second component engages with the second electrode assembly. The first component and the second component are connected to one of the insulating components.

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