Power storage device and method for manufacturing the same

Abstract

The present application provides a power storage device and a manufacturing method thereof. In the power storage device, a welding portion (800) in which a first conductive member (420) and a second conductive member (440) are welded is formed, an outer periphery of a base portion (470A) includes a first portion (471) located in the vicinity of the welding portion (800) and a second portion (472) other than the first portion (471), and an outer peripheral wall is not formed in the first portion (471), or a maximum value of a height of the outer peripheral wall at the first portion (471) is smaller than a maximum value of a height of the outer peripheral wall (472A, 472B) at the second portion (472).

Description

Technical Field

[0001] This technology relates to energy storage devices and their manufacturing methods. Background Technology

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

[0003] In energy storage devices, insulating components are provided to ensure electrical insulation at designated locations. There is a need to improve the reliability of ensuring insulation through these insulating components. Based on this viewpoint, there is still room for improvement regarding the battery described in Japanese Patent No. 4537353. Summary of the Invention

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

[0005] This technology provides the following energy storage devices and methods for manufacturing them.

[0006] [1]

[0007] An energy storage device includes: an electrode body comprising a first electrode and a second electrode having a polarity different from the first electrode; a housing housing the electrode body and including a housing body having a first opening and a first sealing plate sealing the first opening; a first conductive member; a second conductive member connected to the first conductive member; a first electrode terminal electrically connected to the second conductive member and disposed on the first sealing plate; and a first insulating member including components disposed on the second conductive member. The energy storage device has a base between the component and the first sealing plate, and an outer peripheral wall formed on the outer periphery of the base and erected in a direction intersecting the extension direction of the base. The energy storage device has a welded portion formed by welding the first conductive component and the second conductive component. The outer periphery of the base includes a first portion located near the welded portion and a second portion other than the first portion. The outer peripheral wall is not formed in the first portion, or the maximum height of the outer peripheral wall at the first portion is less than the maximum height of the outer peripheral wall at the second portion.

[0008] [2]

[0009] In the energy storage device described in [1], the first conductive member includes a first plate-shaped portion having a pair of opposing first main surfaces and a first side end surface connecting the pair of first main surfaces. The second conductive member includes a second plate-shaped portion having a pair of opposing second main surfaces and a second side end surface connecting the pair of second main surfaces. The first conductive member and the second conductive member are arranged such that one of the pair of first main surfaces abuts against one of the pair of second main surfaces. The welding portion is formed on the first side end surface and the second side end surface.

[0010] [3]

[0011] In the energy storage device described in [1] or [2], the first conductive member includes a first region and a second region, the second conductive member includes a third region and a fourth region, a second insulating member is disposed between the first region and the third region, and the second region abuts against the fourth region.

[0012] [4]

[0013] In any of the following descriptions of the energy storage device, the outer periphery of the base includes a pair of opposing first end edges and a pair of opposing second end edges extending in a direction intersecting the first end edges. The outer periphery wall is provided on each of the pair of first end edges, and the outer periphery wall is provided on one of the pair of second end edges. The other of the pair of second end edges includes the first portion.

[0014] [5]

[0015] In any of the energy storage devices described in [1] to [4],

[0016] When viewed from a direction orthogonal to the extension direction of the base, the outer periphery of the base protrudes beyond the second conductive member, and the amount of protrusion (W1) of the outer periphery of the base at the first part is greater than the amount of protrusion (W2) of the outer periphery of the base at the second part.

[0017] [6]

[0018] A method for manufacturing an energy storage device, the energy storage device comprising: an electrode body including a first electrode, a second electrode with a polarity different from the first electrode, and a first electrode tab electrically connected to the first electrode; a housing housing the electrode body and including a housing body having a first opening and a first sealing plate sealing the first opening; a first conductive member electrically connected to the first electrode tab; a second conductive member connected to the first conductive member; a first electrode terminal electrically connected to the second conductive member and disposed on the first sealing plate; and a first insulating member including a base disposed between the second conductive member and the first sealing plate, and an outer peripheral wall formed on the outer periphery of the base and erected in a direction intersecting the extending direction of the base, wherein... The manufacturing method of the above-mentioned energy storage device includes the following steps: inserting the electrode body into the housing body; and after inserting the electrode body into the housing body, joining the first conductive member electrically connected to the first electrode via the first electrode tab to the second conductive member. The joining of the first conductive member to the second conductive member includes irradiating at least one of the first conductive member and the second conductive member with an energy line to weld the first conductive member and the second conductive member to form a welded part. The outer periphery of the base includes a first part located near the welded part and a second part other than the first part. The first part does not have an outer peripheral wall, or the maximum height of the outer peripheral wall at the first part is less than the maximum height of the outer peripheral wall at the second part.

[0019] [7]

[0020] In the method for manufacturing an energy storage device described in [6], before joining the first conductive component to the second conductive component, the second conductive component is electrically connected to the first electrode terminal. The process of joining the first conductive component to the second conductive component includes a step of welding the first conductive component to the second conductive component by irradiating an energy line from between the housing body and the first sealing plate to at least one of the first conductive component and the second conductive component.

[0021] The above and other objects, features, aspects and advantages of the invention will become clear from the following detailed description in relation to the invention, which is understood in conjunction with the accompanying drawings. Attached Figure Description

[0022] Figure 1 This is a front view showing the structure of the secondary battery involved in the embodiment.

[0023] Figure 2 This indicates viewing from the direction of arrow II. Figure 1 The diagram shows the state of the secondary battery.

[0024] Figure 3 This indicates viewing from the direction of arrow III. Figure 1 The diagram shows the state of the secondary battery.

[0025] Figure 4 This indicates viewing from the direction of arrow IV. Figure 1 The diagram shows the state of the secondary battery.

[0026] Figure 5 This indicates viewing from the direction of arrow V. Figure 1 The diagram shows the state of the secondary battery.

[0027] Figure 6 yes Figure 1 The image shows a front cross-sectional view of a secondary battery.

[0028] Figure 7 This is a cross-sectional view of the negative electrode plate.

[0029] Figure 8 This is the front view of the negative electrode plate.

[0030] Figure 9 This is a cross-sectional view of the positive electrode plate.

[0031] Figure 10 This is the front view of the positive electrode plate.

[0032] Figure 11 yes Figure 1 The XI-XI cross-sectional view of the secondary battery shown.

[0033] Figure 12 yes Figure 1 The XII-XII cross-sectional view of the secondary battery shown.

[0034] Figure 13 This is a flowchart illustrating a method for manufacturing a secondary battery according to one embodiment.

[0035] Figure 14 This is a perspective view showing the state of the secondary battery according to one embodiment before the two electrode bodies overlap.

[0036] Figure 15 yes Figure 14 The XV-XV cross-sectional view of the electrode body and the current collector is shown.

[0037] Figure 16 It is a perspective view showing the state in which the electrode body is equipped with retaining and isolating components.

[0038] Figure 17 It is a three-dimensional diagram showing the current collector on the negative side with a sealing plate installed.

[0039] Figure 18 yes Figure 17 The XVIII-XVIII sectional view of the electrode body and the current collector shown.

[0040] Figure 19 It is a three-dimensional diagram showing the current collector on the positive side with a sealing plate installed.

[0041] Figure 20 It is a three-dimensional diagram showing the structure of a secondary battery.

[0042] Figure 21 It is a three-dimensional view showing the current collector structure on the positive side before the conductive components are joined together.

[0043] Figure 22 yes Figure 21 Sectional view of XXII-XXII in the middle.

[0044] Figure 23 It is a cross-sectional view showing the junction after the irradiation energy line.

[0045] Figure 24 This is the front view of the insulating component.

[0046] Figure 25 This is a three-dimensional view of the insulating component (one of the three).

[0047] Figure 26 This is a three-dimensional view of the insulating component (Part Two).

[0048] Figure 27 It is a three-dimensional view of the insulating component (Part Three).

[0049] Figure 28 This is a front view showing the state where conductive components are installed on insulating components.

[0050] Figure 29 It is a three-dimensional diagram showing the state in which conductive components are installed on insulating components.

[0051] Figure 30 This is a side view showing a conductive component mounted on an insulating component.

[0052] Figure 31 This is an enlarged view showing one end of an insulating component.

[0053] Figure 32 This is an enlarged view showing the other end of the insulating component.

[0054] Figure 33This is a diagram (one of many) showing the formation process of the joint of the conductive components in the positive electrode current collector structure.

[0055] Figure 34 This is a diagram (Part Two) showing the formation process of the joint of the conductive components in the positive electrode current collector structure.

[0056] Figure 35 This is a diagram (third one) showing the formation process of the joint of the conductive components in the positive electrode current collector structure.

[0057] Figure 36 This is a diagram (fourth one) showing the formation process of the joint of the conductive components in the positive electrode current collector structure. Detailed Implementation

[0058] The embodiments of this technology will be described below. Furthermore, there are cases where the same or equivalent parts are labeled with the same reference numerals in the accompanying drawings, and their descriptions will not be repeated.

[0059] Furthermore, in the embodiments described below, when numbers, quantities, etc., are mentioned, the scope of this technology is not 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 achieve all the effects mentioned in this embodiment.

[0060] Furthermore, in this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a structure is included, other structures besides that structure may be included, or they may not be included.

[0061] Furthermore, in this specification, when using geometric terms and terms indicating positional or directional relationships, such as "parallel," "orthogonal," "45° oblique," "coaxial," and "along," these terms allow for some errors or variations. In this specification, when using terms indicating relative positional relationships such as "upper side" and "lower side," these terms are used to indicate the relative positional relationship in one state. Depending on the orientation of each mechanism (e.g., reversing the overall structure vertically), the relative positional relationship can be reversed or rotated to any angle.

[0062] Furthermore, the dimensions of the components illustrated in this specification, such as width, length, and diameter, are not limited to those shown and may be appropriately changed. In this specification, ordinal numbers such as "first," "second," etc., are sometimes added to various structures, but unless explicitly specified, these ordinal numbers do not define priority or order.

[0063] 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."

[0064] 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.

[0065] 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.

[0066] In this specification, the X direction is sometimes referred to as the "width direction" of the secondary battery, electrode body, and housing body, and similarly the Z direction is referred to as the "height direction" of the secondary battery or housing body, and the Y direction is referred to as the "thickness direction" of the secondary battery or housing body.

[0067] (The overall structure of a secondary battery)

[0068] Reference Figures 1-6 The overall structure of the secondary battery 1 is 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.

[0069] When constructing a battery pack containing secondary batteries 1, multiple secondary batteries 1 are stacked in their thickness direction. The stacked secondary batteries 1 can be constrained in the stacking direction (Y direction) by a constraining member to form a battery module, or they can be configured as a battery pack directly supported by the side of the battery pack housing without using a constraining member.

[0070] The housing body 110 is composed of a cylindrical, preferably square, component. This results in a square secondary battery 1. The housing body 110 is made of metal. Specifically, the housing body 110 is made of aluminum, aluminum alloy, iron, or iron alloy, etc.

[0071] like Figure 1 and Figure 2As 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) can be joined together (e.g., by laser welding or other energy line irradiation) to form a square tube shape. The corners of the "square tube" may also have an R-shape. The secondary battery in this technology is not limited to a square secondary battery.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] like Figure 2As 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.

[0077] like Figure 3 As 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 rounded corners.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] The positive terminal 302 provided on the sealing plate 130 includes both the case where the positive terminal 302 is disposed on the sealing plate 130 via an insulating component or the like, and the case where the positive terminal 302 is directly disposed on the sealing plate 130.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] The positive terminal 302 is made of a conductive material (more specifically a metal), such as aluminum or an aluminum alloy.

[0087] The injection port 134 is sealed by a sealing component (not shown). Such sealing components can be, for example, blind rivets or other metal parts.

[0088] The electrode body 200 is a flat electrode body formed by stacking negative and positive electrode plates, as described later. Specifically, the electrode body 200 is a stacked electrode body in which multiple negative electrode plates and multiple 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 electrode plates and strip-shaped 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 comprising multiple negative electrode plates and multiple positive electrode plates, negative electrode tabs (second electrode tabs) provided on each negative electrode plate can be stacked to form a negative electrode tab group, and positive electrode tabs (first electrode tabs) provided on each positive electrode plate can be stacked to form a positive electrode tab group.

[0089] like Figure 6 As shown, the housing 100 houses 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 such that its long side is parallel to the X direction.

[0090] 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.

[0091] 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.

[0092] 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 of the first electrode body 201 in the X direction (towards the sealing plate 120) relative to the main body. The positive electrode tab assembly 250 is located at the end of the first electrode body 201 in the X direction (towards the sealing plate 130) relative to the main body.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] (Structure of electrode body 200)

[0098] like Figure 7 and Figure 8 As shown, the negative electrode plate 210 has a different polarity than the positive electrode plate 240. 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. 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 shape illustrated in .

[0099] 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 formed 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. 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 of the multiple positive electrode plates 240 is appropriately adjusted. The shape of the positive electrode tab 260 is not limited to... Figure 10 The shape illustrated in .

[0100] A positive electrode protection layer 243 is provided at the root of the positive electrode tab 260. Alternatively, it may not be necessary to provide a positive electrode protection layer 243 at the root of the positive electrode tab 260.

[0101] 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.

[0102] (Connection structure between electrode 200 and current collector 400)

[0103] Reference Figure 11 and Figure 12 The connection structure between the electrode body 200 and the current collector 400 will be described.

[0104] 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 contain a positive electrode and a negative electrode. The electrode body 200 may also be composed of three or more electrode bodies.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] The negative electrode tab assembly 220 has a first recess 220R that is recessed toward the negative electrode tab assembly 270 when bent. The negative electrode tab assembly 270 has a second recess 270R that is recessed toward the negative electrode tab assembly 220 when bent.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] Negative electrode tabs 220 and 270 are described later (see reference). Figure 15 The joining portion 411 is joined to the current collector 410. The joining portion 411 can be formed, for example, by ultrasonic welding, resistance welding, laser welding, riveting, etc. In this embodiment, the negative electrode tabs 220, 270 and the current collector 410 are joined, for example, by ultrasonic joining.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] A spacer 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 spacer 600 is made of an insulating resin component. The spacer 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, negative electrode tabs 270, and the electrode body 200. The protrusions of the spacer 600 are disposed within the first recess 220R and the second recess 270R.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] The positive electrode tab assembly 250 has a first recess 250R that is recessed toward the positive electrode tab assembly 280 when bent. The positive electrode tab assembly 280 has a second recess 280R that is recessed toward the positive electrode tab assembly 250 when bent. The protrusion provided in the separator 600 is disposed within the first recess 250R and the second recess 280R.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] Positive electrode tab assembly 250 and positive electrode tab assembly 280 are joined at the following location 421 (see reference). Figure 15 The positive electrode tab 250 and the positive electrode tab 280 and the current collector 420 are joined together, for example, by ultrasonic welding, resistance welding, laser welding, riveting, etc. In this embodiment, the positive electrode tab 250 and the positive electrode tab 280 and the current collector 420 are joined together, for example, by ultrasonic welding.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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).

[0137] 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).

[0138] (Manufacturing process of secondary battery 1)

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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 18As 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.

[0149] 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.

[0150] Next, with the current collector 420 side as the front, the separator 600 and the electrode body 200 are inserted into the housing body 110 through the opening 113 (step S7). Then, by bringing the sealing plate 120 close to the main body of the electrode body 200 (first electrode body 201 and second electrode body 202), the negative electrode tab group 220 and negative electrode tab group 270 are bent from their extending states. 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] The positive electrode tabs 250 and 280, connected to the current collector 420, are bent so that their front ends 252 and 282 face each other. For example... Figure 12As 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.

[0155] 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).

[0156] 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.

[0157] 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.

[0158] 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.

[0159] 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.

[0160] (Current collector structure on the positive side)

[0161] like Figure 21 and Figure 22 As shown, current collectors 420 and 440 are plate-shaped components having a long side in the Z-axis direction and a short side in the Y-axis direction. For current collectors 420 and 440, aluminum or an aluminum alloy is preferably used.

[0162] Current collector 420 (first conductive member) has a first region R1 and a second region R2. Current collector 440 (second conductive member) has a third region R3 and a fourth region R4. An insulating member 460 is disposed between the first region R1 of current collector 420 and the third region R3 of current collector 440. An insulating member 470 is disposed between sealing plate 130 and current collector 440.

[0163] In the direction perpendicular to the sealing plate 130 (X direction), the surface of the second region R2 of the current collector 420 on the sealing plate 130 side is positioned closer to the sealing plate 130 side than the surface of the first region R1 on the sealing plate 130 side. The current collector 420 can be formed by bending.

[0164] A contact portion TR1 is provided between the second region R2 of current collector 420 and the fourth region R4 of current collector 440, where the second region R2 and the fourth region R4 abut. Current collector 420 and current collector 440 are joined to each other at the upper end of the contact portion TR1.

[0165] like Figure 21 and Figure 22 As shown, before the current collector 420 and the current collector 440 are joined, the current collectors 420 and 440 respectively have a protrusion 420A (first protrusion) and a protrusion 440A (second protrusion) at the upper end of the contact portion TR1. Figure 21 , Figure 22 In the example, protrusions 420A and 440A abut against each other. However, a gap may also be provided between protrusions 420A and 440A. Alternatively, only one of protrusions 420A and 440A may be provided.

[0166] Current collectors 420 and 440 are joined together by irradiating energy lines onto the protrusions 420A and 440A. Preferably, current collectors 420 and 440 are joined by welding. More preferably, current collectors 420 and 440 are joined by laser welding.

[0167] In the portion irradiated by the energy line, the height of protrusions 420A and 440A decreases. In the portion irradiated by the energy line, protrusions 420A and 440A largely disappear, but sometimes they do not completely disappear.

[0168] After the electrode body 200 is inserted into the housing body 110, during the joining process of the current collectors 420 and 440, at least one of the protrusions 420A of the current collector 420 and 440A of the current collector 440 is irradiated with energy lines (preferably laser) from between the housing body 110 and the sealing plate 130. This forms a joint between the current collectors 420 and 440. Alternatively, the current collectors 420 and 440 can be joined before the electrode body 200 is inserted into the housing body 110.

[0169] The current collector 420 has an inclined portion T12 (stepped portion) between the first region R1 and the second region R2, and a gap S1 is provided between the inclined portion T12 and the current collector 440. The gap S1 gradually decreases towards the second region R2. Furthermore, the gap S1 has a region where no insulating member 460 is disposed. By providing the gap S1, the dissipation of heat generated during the formation of the joint of the current collectors 420 and 440 to the first region R1 and the third region R3 can be suppressed. Therefore, the joint 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.

[0170] The second region R2 (first plate-like portion) of the current collector 420 has a pair of opposing main surfaces (first main surfaces), and a protrusion 420A is formed on the upper end surface (first side end surface) connecting the pair of main surfaces. The fourth region R4 (second plate-like portion) of the current collector 440 has a pair of opposing main surfaces (second main surfaces), and a protrusion 440A is formed on the upper end surface (second side end surface) connecting the pair of main surfaces.

[0171] Through such Figure 21 , Figure 22 In the example described, energy lines are irradiated onto the protrusions 420A and 440A located at the upper ends of the current collectors 420 and 440 to perform the connection. This allows the heat generated by the irradiation of the energy lines to be concentrated around the protrusions 420A and 440A, thereby achieving a highly efficient (with less energy) and reliable connection. However, in the secondary battery 1 according to this embodiment, the shape of the connection portion of the current collectors 420 and 440 is not particularly limited.

[0172] like Figure 23 As shown, a joint portion 800 (welding portion) is formed to join current collectors 420 and 440. The joint portion 800 is formed at the +Z side end of the current collectors 420 and 440, but the forming location of the joint portion 800 is not limited to this. Figure 23 As shown, preferably, the center (deepest part) of the joint 800 coincides with the boundary (abutment part TR1) of the current collectors 420 and 440. However, the center of the joint 800 may also be located at... Figure 23The state shown is slightly offset toward the collector 420 side (-X side) or the collector 440 side (+X side).

[0173] (Insulating component 470)

[0174] like Figures 24-27 As shown, the insulating member 470 (first insulating member) includes a base 470A and a through hole 470B. The base 470A is formed in a plate shape and is disposed along the sealing plate 130. Therefore, the base 470A extends along the Y-Z plane when the insulating member 470 is mounted on the sealing plate 130. The base 470A is disposed between the current collector 440 and the sealing plate 130. A positive terminal 302 is inserted through the through hole 470B.

[0175] The base 470A has a generally rectangular shape comprising a pair of long sides (first end sides) and a pair of short sides (second end sides). The term "generally rectangular shape" as used herein includes shapes with R-shaped corners and shapes with cutouts formed in a portion of the rectangle. The outer periphery of the base 470A comprises a first portion 471 (the short side on the +Z side) and a second portion 472 (the short side on the -Z side and a pair of long sides). However, the "generally rectangular shape" is not necessarily limited to having long and short sides, and includes a "generally square" shape. Furthermore, the shape of the base is not limited to a "generally rectangular shape".

[0176] In both parts 471 and 472, part 471 does not have an outer peripheral wall, while at least a portion of part 472 has outer peripheral walls 472A and 472B. The outer peripheral walls 472A and 472B are configured to stand upright from the base 470A toward the electrode body 200 when the insulating member 470 is mounted on the sealing plate 130. Part 471 is disposed on one side of the current collectors 420 and 440 forming the joint 800 (in this embodiment, the +Z side).

[0177] One pair of outer peripheral walls 472A (first wall) are provided on a pair of long sides of the base 470A, and the outer peripheral wall 472B (second wall) is provided on the short side of the base 470A on the -Z side. However, depending on the formation location of the joint, one pair of outer peripheral walls 472A may be provided on the short side of the base 470A, and the outer peripheral wall 472B may be provided on the long side of the base 470A.

[0178] The outer peripheral wall 472A extends along the Z direction (the height direction of the secondary battery 1) with the insulating component 470 mounted on the sealing plate 130. The outer peripheral wall 472B extends along the Y direction (the thickness direction of the secondary battery 1) with the insulating component 470 mounted on the sealing plate 130.

[0179] like Figures 24-27As shown, the outer peripheral walls 472A and 472B are preferably provided continuously in a manner that extends substantially along the three sides of a generally rectangular shape. However, compared with... Figures 24-27 Compared to the example shown, the outer peripheral wall 472A may also be provided only within a shorter range defined on the -Z side. Additionally, portions of the outer peripheral walls 472A and 472B may be provided intermittently.

[0180] In this embodiment, a junction 800 with the current collector 420 is formed almost entirely over the top of the current collector 440 in the Y direction. Therefore, in the insulating member 470 illustrated here, the first portion 471 (the portion without the outer peripheral walls 472A and 472B) is formed almost entirely over the short side of the +Z side of the generally rectangular shape when the insulating member 470 is mounted on the sealing plate 130.

[0181] However, when viewed from the +Z side (the side forming the joint 800), the first part 471 can be provided in the forming area of ​​the joint 800 and its adjacent area (in this specification, these areas are collectively referred to as the "nearby" of the joint 800), and the configuration of the first part 471 can also be changed according to the forming area of ​​the joint 800. For example, an outer peripheral wall 472A, 472B may be provided on a portion of the short side (upper side) of the base 470A on the +Z side. In this case, the portion provided with the outer peripheral wall 472A, 472B becomes the second part 472. Furthermore, when viewed from the +Z side (the side forming the joint 800), the aforementioned "adjacent area" refers to the area from the edge of the joint 800 to a predetermined distance (at least 1 mm, more preferably at least 3 mm, and even more preferably 5 mm).

[0182] For example, if the base 470A of the insulating member 470 has a rectangular shape comprising four end edges, as a preferred embodiment, a first portion 471 may be provided on the end edge closest to the joint 800 among the four end edges. In this case, a second portion 472 may be provided on the other three end edges besides the end edge on which the first portion 471 is provided.

[0183] Preferably, the first part 471 is arranged in a manner that extends over, for example, both sides of a generally rectangular shape, according to the forming area of ​​the joint 800. For example, such as... Figures 24-30As shown, preferably, the first portion 471 is also provided at both ends of the two corner portions of the short side (second end edge) located on the +Z side of the outer periphery of the base 470A, where the first portion 471 is provided. Furthermore, preferably, the first portion 471 is also provided at the ends of a pair of long sides (first end edges) of the outer periphery of the base 470A that are connected to the two corner portions where the first portion 471 is provided. Preferably, the first portion 471 is provided on the long side (first end edge) in a manner that connects to the vicinity of the corner portion where the first portion 471 is provided. Furthermore, preferably, the length of the region where the first portion 471 is provided on the second end edge (long side) is 0.5 mm or more, more preferably 1 mm or more. Additionally, preferably, the length of this region is 10 mm or less, more preferably 5 mm or less.

[0184] A protrusion 472C (fitting protrusion) is formed on the outer peripheral wall 472A. The protrusion 472C is formed in such a way that it protrudes inward from the outer peripheral wall 472A. The protrusion 472C can help to position the current collector 440 mounted on the insulating member 470. However, it is not necessary to provide the protrusion 472C.

[0185] In part or all of the first part 471 (above the base 470A), an outer peripheral wall (not shown) with a height lower than the outer peripheral walls 472A and 472B of the second part 472 may also be formed. When the outer peripheral wall with a height lower than the outer peripheral walls 472A and 472B of the second part 472 is provided in the first part 471, the maximum value of the height of the outer peripheral wall provided in the first part 471 is preferably less than 1 / 2 (more preferably less than 1 / 3, and even more preferably less than 1 / 10) of the maximum value of the height of the outer peripheral walls 472A and 472B. Furthermore, the average value of the height of the outer peripheral wall provided in the first part 471 is preferably lower than the average value of the height of the outer peripheral walls 472A and 472B of the second part 472.

[0186] In this way, by adopting a structure in which the insulating member 470 is not provided with an outer peripheral wall (or has a relatively low height) in the first part 471 located near the joint 800, it is possible to suppress the damage to the insulating member 470 caused by heat or the like during the formation of the joint 800, and to improve the reliability of ensuring insulation through the insulating member 470.

[0187] like Figures 28-30 As shown, the current collector 440 includes a through hole 440B, a notch 440C (fitting recess), and a protrusion 440D. As... Figure 28As shown, when viewed from a direction orthogonal to the extending direction (Y-Z plane direction) of the base 470A of the insulating member 470 (X direction), the outer periphery of the base 470A protrudes more than the current collector 440. Preferably, the outer periphery of the base 470A of the insulating member 470 protrudes relatively more in the first part 471 than in the second part 472.

[0188] The through hole 440B of the current collector 440 communicates with the through hole 470B of the insulating member 470. A positive terminal 302 is inserted through the through hole 440B. The cutout 440C of the current collector 440 engages with the protrusion 472C of the insulating member 470, which helps in aligning the current collector 440 and the insulating member 470. However, the cutout 440C may not be necessary. The protrusion 440D of the current collector 440 engages with a recess or hole (not shown) formed in the insulating member 460 (the second insulating member) disposed between the current collectors 420 and 440, which also helps in aligning the current collector 440 and the insulating member 460.

[0189] like Figure 31 , Figure 32 As shown, on one side (-Z side) of the base 470A, the short side ( Figure 31 ) and the shorter side on the other side (+Z side) Figure 32 When comparing, it is preferable that the amount of protrusion of the outer periphery of the base 470A in the first part 471 (W1: the amount of protrusion of the base 470A) is greater than the amount of protrusion of the outer periphery of the base 470A in the second part 472, where the outer peripheral wall 472B is provided (W2: the thickness of the outer peripheral wall 472B). More preferably, W1 / W2 is 1.2 or more, more preferably W1 / W2 is 1.8 or more, and even more preferably W1 / W2 is 3 or more.

[0190] In addition, such as Figure 32 As shown, the upper end 472A1 (the end on the +Z side) of the outer peripheral wall 472A is located further away from the first part 471 (on the -Z side) than the current collector 440.

[0191] As described above, by increasing the protrusion of the base 470A on the first part 471 side, even in the first part 471 which has no outer peripheral wall (or the height of the outer peripheral wall is relatively low), the surface distance of the insulating member 470 from the sealing plate 130 to the current collector 440 can be maintained to a greater extent. Therefore, it is possible to suppress the occurrence of electrical short circuits between the sealing plate 130 and the current collector 440, and further improve the reliability of insulation through the insulating member 470.

[0192] Furthermore, by positioning the upper end 472A1 (the end on the +Z side) of the outer peripheral wall 472A below the current collector 440 (on the -Z side), damage to the outer peripheral wall 472A during the formation of the joint 800 can be suppressed, thereby further improving the reliability of insulation ensured by the insulating member 470.

[0193] In the secondary battery 1 according to this embodiment, the shapes of the current collectors 420 and 440 constituting the current collector structure on the positive electrode side are not particularly limited. For example, they can be as follows: Figure 33 As shown, the joint 800 (welding part) can be formed by irradiating the protrusions formed on the current collectors 420 and 440 with laser 2 (energy line). Figure 34 , Figure 35 As shown, laser 2 is irradiated onto the boundary portions of current collectors 420 and 440 without protrusions to form the joint 800. Alternatively, it can be done as follows... Figure 36 As shown, laser 2 is irradiated onto the portion formed by the overlapping of current collectors 420 and 440, which are roughly L-shaped, to form the junction 800.

[0194] In the secondary battery 1 according to this embodiment, it is preferable that the joint 800 (welded portion) formed by joining the current collector 420 (first conductive member) and the current collector 440 (second conductive member) is formed at a position opposite to the inner surface of the second side portion 112B of the housing body 110. In this way, the joint 800 can be formed by irradiating an energy line from between the housing body 110 and the sealing plate 130 onto at least one of the current collectors 420 and 440. As a result, a more reliable secondary battery 1 with higher volume density and reduced damage to the insulating members 460 and 470 during the formation of the joint 800 can be provided. In addition, when the insulating members 460 and 470 are made of resin, it is also possible to effectively suppress the situation where a portion of the insulating members 460 and 470 carbonizes due to the heat of the laser 2 (energy line), thereby generating conductive foreign matter.

[0195] While embodiments of the present invention have been described, it should be understood that the embodiments disclosed herein are illustrative in all respects and not limiting. The scope of the invention is shown by the technical solutions and is intended to include all modifications within the meaning and scope of equivalent technical solutions.

Claims

1. An energy storage device, characterized in that, have: An electrode body comprising a first electrode and a second electrode having a polarity different from that of the first electrode; The housing houses the electrode body and includes a housing body having a first opening and a first sealing plate for sealing the first opening; First conductive component; A second conductive component, which is connected to the first conductive component; The first electrode terminal is electrically connected to the second conductive component and is disposed on the first sealing plate; as well as The first insulating component includes a base disposed between the second conductive component and the first sealing plate, and an outer peripheral wall formed on the outer periphery of the base and erected in a direction intersecting the extending direction of the base. The energy storage device has a welded section formed by welding the first conductive component and the second conductive component. The outer periphery of the base includes a first portion located near the welded portion and a second portion other than the first portion. The outer peripheral wall is not formed in the first part, or the maximum height of the outer peripheral wall in the first part is less than the maximum height of the outer peripheral wall in the second part.

2. The energy storage device according to claim 1, characterized in that, The first conductive component includes a first plate-shaped portion, the first plate-shaped portion having a pair of first main surfaces facing each other and a first side end surface connecting the pair of first main surfaces. The second conductive component includes a second plate-shaped portion, the second plate-shaped portion having a pair of opposing second main surfaces and a second side end surface connecting the pair of second main surfaces. The first conductive component and the second conductive component are arranged such that one of the pair of first main surfaces and one of the pair of second main surfaces abut against each other. The weld portion is formed on the first side end face and the second side end face.

3. The energy storage device according to claim 1 or 2, characterized in that, The first conductive component includes a first region and a second region, and the second conductive component includes a third region and a fourth region. A second insulating component is disposed between the first region and the third region. The second region is adjacent to the fourth region.

4. The energy storage device according to claim 1 or 2, characterized in that, The outer periphery of the base includes a pair of first end edges that are opposed to each other, and a pair of second end edges that are opposed to each other and extend in a direction that intersects with respect to the first end edges. The outer peripheral wall is provided on each of the pair of first end edges. The outer peripheral wall is provided on one of the pair of second end edges, and the other of the pair of second end edges includes the first portion.

5. The energy storage device according to claim 1 or 2, characterized in that, When viewed from a direction orthogonal to the extending direction of the base, the outer periphery of the base protrudes beyond the second conductive member. The amount of protrusion W1 of the outer periphery of the base at the first part is greater than the amount of protrusion W2 of the outer periphery of the base at the second part.

6. A method for manufacturing an energy storage device, the energy storage device comprising: An electrode body comprising a first electrode, a second electrode having a polarity different from that of the first electrode, and a first electrode tab electrically connected to the first electrode; The housing houses the electrode body and includes a housing body having a first opening and a first sealing plate for sealing the first opening; A first conductive component, which is electrically connected to the first electrode tab; A second conductive component, which is connected to the first conductive component; The first electrode terminal is electrically connected to the second conductive component and is disposed on the first sealing plate; as well as The first insulating component includes a base disposed between the second conductive component and the first sealing plate, and an outer peripheral wall formed on the outer periphery of the base and erected in a direction intersecting the extending direction of the base. The manufacturing method of the energy storage device is characterized by comprising the following steps: The process of inserting the electrode body into the housing body; and After inserting the electrode body into the housing body, the process of joining the first conductive component, which is electrically connected to the first electrode via the first electrode tab, with the second conductive component. The process of joining the first conductive component and the second conductive component includes the step of irradiating at least one of the first conductive component and the second conductive component with an energy line to weld the first conductive component and the second conductive component to form a welded part. The outer periphery of the base includes a first portion located near the welded portion and a second portion other than the first portion. The outer peripheral wall is not formed in the first part, or the maximum height of the outer peripheral wall in the first part is less than the maximum height of the outer peripheral wall in the second part.

7. The method for manufacturing an energy storage device according to claim 6, characterized in that, Before joining the first conductive component to the second conductive component, the second conductive component is electrically connected to the first electrode terminal. The process of joining the first conductive component and the second conductive component includes the step of irradiating an energy line from between the housing body and the first sealing plate onto at least one of the first conductive component and the second conductive component to weld the first conductive component and the second conductive component.

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