Battery with fixing member

Abstract

The present application provides a battery capable of properly preventing damage to a group of electrode tabs. A battery (100) disclosed herein includes: electrode bodies (20a, 20b, 20c) in a flat hexahedral shape including positive electrodes (22) and negative electrodes (24) and having a pair of flat outer surfaces (27) in a rectangular shape, and a battery case (10) that houses the electrode bodies. In this case, a fixing member (1) is disposed from one of the flat outer surfaces (27) of at least one pair of flat outer surfaces (27) of the electrode bodies (20a, 20c) to a positive electrode current collecting portion (50) or a negative electrode current collecting portion (60).

Description

[0001] This application is a divisional application of the invention patent application entitled "Battery with Fixing Components", filed on June 8, 2022, with application number 202210642734.4. Technical Field

[0002] This disclosure relates to batteries with fixed components. Background Technology

[0003] Lithium-ion rechargeable batteries typically include: a flat, hexahedral electrode body having a positive and a negative electrode (hereinafter also simply referred to as "electrode"); an outer casing having an opening and housing the electrode body; a sealing plate sealing the opening of the outer casing; and terminals electrically connected to the electrodes inside the outer casing and extending outward from the sealing plate to the outside of the outer casing. Such batteries typically include an electrode tab assembly with multiple tabs for current collection on the electrodes, the electrode tab assembly having a structure connected to the terminal via an electrode current collector. For example, Patent Document 1 discloses a battery in which a positive electrode tab assembly is provided at one end along the long side of the electrode body and a negative electrode tab assembly is provided at the other end. Furthermore, it discloses a technique for connecting the electrode tab assembly to the electrode current collector in a bent state.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2017-50069

[0007] Furthermore, during battery use, external forces such as vibration and impact may be applied to the battery. The tabs, for example, are part of the current collector and are flexible and easily affected by external forces. Therefore, when the electrode body is displaced from its intended position due to external force (specifically, an external force applied along the long side of the electrode body) and a load is applied to the electrode tab assembly, the electrode tab assembly may be damaged. As a result, the electrical connection between the electrode and the terminal may become unstable or poor, which is therefore undesirable. Additionally, according to the inventors' research, particularly when the electrode tab assembly is connected to the electrode current collector in a bent state, the external force is concentrated on the bent portion, thus the electrode tab assembly is easily damaged. Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] The present invention was made in view of the above circumstances, and its main objective is to provide a battery that can properly prevent damage to the electrode tab assembly.

[0010] Technical solutions for solving the problem

[0011] According to this disclosure, a battery is provided, comprising: a first electrode body in the shape of a flat hexahedron, the first electrode body including a positive electrode and a negative electrode, and having a pair of rectangular flat outer surfaces; and a battery housing housing the first electrode body. The battery housing comprises: an outer body having a bottom wall, a pair of first sidewalls extending from the bottom wall and facing each other, a pair of second sidewalls extending from the bottom wall and facing each other, and an opening facing the bottom wall; and a sealing plate sealing the opening. A positive terminal and a negative terminal are mounted on the sealing plate, a positive electrode tab group including a plurality of positive electrode tabs is disposed on the second sidewall of one of the pair of second sidewalls, and a negative electrode tab group including a plurality of negative electrode tabs is disposed on the second sidewall of the other of the pair of second sidewalls. The positive electrode tab assembly and the positive terminal are electrically connected via a positive current collector. The positive electrode tab assembly is engaged with the positive current collector in a bent state extending along the second sidewall. The negative electrode tab assembly and the negative terminal are electrically connected via a negative current collector. The negative electrode tab assembly is engaged with the negative current collector in a bent state extending along the second sidewall. Here, a fixing member is disposed from at least one of the flat outer surfaces of the pair of flat outer surfaces to the positive or negative current collector.

[0012] By configuring the fixing members as described above, the electrode body is fixed relative to the rigid electrode current collector fixed to the sealing plate, thereby appropriately suppressing movement of the electrode body in the long side direction within the battery casing. This suppresses the load on the electrode tab assembly, thus appropriately preventing damage to the electrode tab assembly.

[0013] In one embodiment of the battery disclosed herein, the positive electrode tab assembly is engaged with the surface of the first electrode body in the positive current collector, and the negative electrode tab assembly is engaged with the surface of the first electrode body in the negative current collector.

[0014] In one embodiment of the battery disclosed herein, the positive electrode tabs are engaged with the positive current collector while being gathered on the flat outer surface side of one of the pair of flat outer surfaces, and the negative electrode tabs are engaged with the negative current collector while being gathered on the flat outer surface side of one of the pair of flat outer surfaces.

[0015] In a preferred embodiment of the battery disclosed herein, the fixing member does not cover either the junction of the positive electrode tab group and the positive current collector, or the junction of the negative electrode tab group and the negative current collector. This structure reliably prevents damage caused by interference between the fixing member and the electrode tab group, thus avoiding damage to the electrode tab group due to load.

[0016] In one embodiment of the battery disclosed herein, the positive electrode tab is made of aluminum or aluminum alloy foil, and the negative electrode tab is made of copper or copper alloy foil. Here, the fixing member is disposed from at least one of the pair of flat outer surfaces to the negative electrode current collector, and the fixing member is not disposed from either of the pair of flat outer surfaces to the positive electrode current collector.

[0017] In a preferred embodiment of the battery disclosed herein, the positive electrode current collector includes: a first positive electrode current collector disposed between the sealing plate and the first electrode body; and a second positive electrode current collector engaged with the positive electrode tab assembly. The negative electrode current collector includes: a first negative electrode current collector disposed between the sealing plate and the first electrode body; and a second negative electrode current collector engaged with the negative electrode tab assembly. Here, the fixing member at least covers the joint between the first and second positive electrode current collectors, or the joint between the first and second negative electrode current collectors. By fixing the electrode body in the electrode current collector near the sealing plate in this way, movement of the electrode body in the long-side direction within the battery casing can be more appropriately suppressed.

[0018] In one embodiment of the battery disclosed herein, the pair of flat outer surfaces are formed of a separator, and a layer comprising polyvinylidene fluoride is formed on the outermost surface of the separator.

[0019] In one embodiment of the battery disclosed herein, a second electrode with the same structure as the first electrode is further disposed within the battery casing.

[0020] In one embodiment of this type of battery, one or more electrode bodies with the same structure as the first electrode body are disposed between the first electrode body and the second electrode body.

[0021] In a preferred embodiment of this battery, the first electrode body, the electrode body disposed between the first electrode body and the second electrode body, and the second electrode body are fixed. According to this structure, movement along the long side of the electrode body disposed between the first and second electrode bodies can be appropriately suppressed.

[0022] In a preferred embodiment of this battery, the fixing members for the first electrode and the second electrode are not disposed between the first electrode, the electrode disposed between the first and second electrodes, or any of the second electrodes. This structure reduces the cumulative thickness of the electrode assembly, thus mitigating the pressure distribution among the individual electrodes. Consequently, uneven reaction in each electrode can be appropriately suppressed.

[0023] In a preferred embodiment of this battery, an auxiliary fixing member is further disposed from the flat outer surface of one of the pair of flat outer surfaces of the first electrode body facing the first sidewall to the flat outer surface of one of the pair of flat outer surfaces of the second electrode body facing the first sidewall. Here, the auxiliary fixing member is disposed on the first electrode body, the electrode body disposed between the first and second electrode bodies, and the portion of the second electrode body other than the positive and negative current collector portions. According to this structure, movement in the long-side direction of the electrode body disposed between the first and second electrode bodies can be appropriately suppressed.

[0024] In a preferred embodiment of this battery, an insulating member is disposed within the battery casing between the first sidewall facing the flat outer surface of the first electrode and the flat outer surface of the first electrode, and between the other first sidewall and the flat outer surface of the second electrode. Here, the coefficient of friction of the first electrode, the electrode disposed between the first and second electrodes, and the second electrode is greater than the coefficient of friction of the insulating member and the flat outer surface of the first electrode, and the coefficient of friction of the insulating member and the flat outer surface of the second electrode. According to this structure, movement along the long side of each electrode can be appropriately suppressed.

[0025] In a preferred embodiment of this battery, the insulating member is made of a resin film, and the coefficient of friction of the first electrode, the electrode disposed between the first electrode and the second electrode, and the second electrode is greater than the coefficient of friction of the insulating member and the first sidewall. According to this structure, movement along the long side of each electrode can be appropriately suppressed. Attached Figure Description

[0026] Figure 1 This is a perspective view schematically showing one embodiment of a battery.

[0027] Figure 2 It is along Figure 1 A schematic longitudinal section view of line II-II.

[0028] Figure 3 It is along Figure 1 A schematic longitudinal section view of line III-III.

[0029] Figure 4 It is along Figure 1 A schematic cross-sectional view of line IV-IV.

[0030] Figure 5 This is a schematic diagram illustrating an embodiment of an electrode assembly mounted on a sealing plate.

[0031] Figure 6 This is a perspective view schematically showing an electrode body with a positive second collector and a negative second collector installed in one embodiment.

[0032] Figure 7 This is a schematic diagram showing the structure of a wound electrode body according to one embodiment.

[0033] Figure 8 It is shown schematically. Figure 2 A magnified cross-sectional view of the vicinity of the positive end.

[0034] Figure 9 This is a perspective view schematically showing a sealing plate with a positive terminal, a negative terminal, a positive first connection portion, a negative first connection portion, a positive insulating member, and a negative insulating member installed according to one embodiment.

[0035] Figure 10 It is Figure 9 A 3D view of the sealing plate turned upside down.

[0036] Figure 11 This is a schematic cross-sectional view illustrating the battery insertion process of one embodiment.

[0037] Figure 12 This is a schematic diagram illustrating an electrode assembly mounted on a sealing plate in another embodiment.

[0038] Figure 13 This is a schematic diagram illustrating an electrode assembly mounted on a sealing plate in another embodiment.

[0039] Figure 14 This is a schematic diagram illustrating an electrode assembly mounted on a sealing plate in another embodiment.

[0040] Figure 15 This is a schematic diagram illustrating an electrode assembly mounted on a sealing plate in another embodiment.

[0041] Explanation of reference numerals in the attached figures

[0042] 1. Fixed components 1a~1g

[0043] 1h~1j Auxiliary fixing components

[0044] 10 Battery casing

[0045] 12 outer body

[0046] 14 Sealing board

[0047] 20 electrode assembly

[0048] Electrode bodies 20a (first electrode), 20b, 20c (second electrode)

[0049] 27. Flat outer surface

[0050] 23 Positive electrode tab assembly (electrode tab assembly)

[0051] 25 Negative electrode tab assembly (electrode tab assembly)

[0052] 30 Positive terminal (terminal)

[0053] 40 Negative terminal (terminal)

[0054] 50 Positive current collector

[0055] 51 Positive electrode first current collector (current collector)

[0056] 52 Positive electrode second current collector

[0057] 60 Negative current collector

[0058] 61 Negative electrode first collector section

[0059] 62 Negative electrode second collector section

[0060] 70 Positive electrode insulating component (insulating component)

[0061] 70a Base section

[0062] 70b Protrusion

[0063] 80 Negative electrode insulating component (insulating component)

[0064] 80a Base

[0065] 80b protrusion

[0066] 100 batteries Detailed Implementation

[0067] Hereinafter, several preferred embodiments of the technology disclosed herein will be described with reference to the accompanying drawings. It should be noted that matters necessary for the implementation of this disclosure, other than those specifically mentioned in this specification (e.g., the general structure and manufacturing process of the battery not representing this disclosure), can be understood as design matters by those skilled in the art based on prior art. This disclosure can be implemented based on the content disclosed in this specification and common technical knowledge in the art. Furthermore, in this specification, the expression "A~B" indicating a numerical range means greater than A and less than B. It also includes the meanings of "greater than A" and "less than B".

[0068] It should be noted that, in this specification, "battery" refers to all energy storage devices capable of extracting electrical energy, encompassing both primary and secondary batteries. Furthermore, in this specification, "secondary battery" refers to all energy storage devices capable of repeated charging and discharging, including lithium-ion secondary batteries, nickel-metal hydride batteries, and other so-called storage batteries (chemical batteries), as well as capacitors such as electric double-layer capacitors (physical batteries).

[0069] <Battery 100>

[0070] Figure 1 This is a 3D image of battery 100. Figure 2 It is along Figure 1 A schematic longitudinal section view of line II-II. Figure 3 It is along Figure 1 A schematic longitudinal section view of line III-III. Figure 4 It is along Figure 1 A schematic cross-sectional view along line IV-IV. It should be noted that in the following description, the reference numerals L, R, F, Rr, U, and D in the figures represent left, right, front, back, top, and bottom, respectively; and the reference numerals X, Y, and Z represent the short side direction of battery 100, the long side direction orthogonal to the short side direction (also referred to as the long side direction of the electrode body), and the up-down direction, respectively. However, these directions are merely for ease of explanation and do not limit the arrangement of battery 100.

[0071] like Figure 2 As shown, the battery 100 includes a battery casing 10, an electrode assembly 20, a positive terminal 30, a negative terminal 40, a positive current collector 50, a negative current collector 60, a positive electrode insulating member 70, and a negative electrode insulating member 80. Although the figures are omitted, the battery 100 also includes an electrolyte. The battery 100 is a lithium-ion secondary battery. The battery 100 is characterized by having a fixing member 1, which will be described later; otherwise, the structure may be the same as conventional batteries. The fixing member 1 is an example of a fixing member disclosed herein.

[0072] The battery casing 10 is a frame that houses the electrode assembly 20. The battery casing 10 has a flat, bottomed cuboid shape (square). The material of the battery casing 10 can be the same as conventionally used materials, without particular limitation. The battery casing 10 is preferably made of metal, and more preferably of materials such as aluminum, aluminum alloy, iron, or iron alloy. Figure 2 As shown, the battery casing 10 includes an outer body 12 with an opening 12h and a sealing plate (cover) 14 that blocks the opening 12h.

[0073] like Figure 1As shown, the outer casing 12 includes a bottom wall 12a, a pair of long sidewalls 12b extending from the bottom wall 12a and facing each other, and a pair of short sidewalls 12c extending from the bottom wall 12a and facing each other. The bottom wall 12a is generally rectangular. The bottom wall 12a faces the opening 12h. The area of ​​the short sidewalls 12c is smaller than the area of ​​the long sidewalls 12b. The long sidewalls 12b and short sidewalls 12c are examples of the first and second sidewalls disclosed herein. A sealing plate 14 is installed on the outer casing 12 to block the opening 12h of the outer casing 12. The sealing plate 14 faces the bottom wall 12a of the outer casing 12. The sealing plate 14 is generally rectangular in plan view. The battery housing 10 is integrated by joining (e.g., welding) the sealing plate 14 to the periphery of the opening 12h of the outer casing 12. The battery housing 10 is hermetically sealed (sealed).

[0074] like Figure 2 As shown, the sealing plate 14 is provided with an injection hole 15, a gas vent valve 17, and two terminal outlet holes 18 and 19. The injection hole 15 is used to inject electrolyte after the sealing plate 14 is assembled to the outer casing 12. The injection hole 15 is sealed by a sealing member 16. The gas vent valve 17 is configured to break when the pressure inside the battery casing 10 reaches a predetermined value, thereby venting the gas inside the battery casing 10 to the outside. The terminal outlet holes 18 and 19 are respectively formed at both ends of the sealing plate 14 in the long side direction Y. The terminal outlet holes 18 and 19 penetrate the sealing plate 14 in the vertical direction Z. The terminal outlet holes 18 and 19 each have an inner diameter that allows the positive terminal 30 and negative terminal 40, which are installed before the sealing plate 14 (before riveting), to be inserted.

[0075] The positive terminal 30 and the negative terminal 40 are respectively fixed to the sealing plate 14. The positive terminal 30 is positioned on one side of the long side Y direction of the sealing plate 14. Figure 1 , Figure 2 (Left side). The negative terminal 40 is positioned on the other side of the long side Y direction of the sealing plate 14 ( Figure 1 , Figure 2 (The right side). For example, Figure 1 As shown, the positive terminal 30 and the negative terminal 40 are exposed on the outer surface of the sealing plate 14. Figure 2 As shown, the positive terminal 30 and the negative terminal 40 are inserted through the terminal lead-out holes 18 and 19 and extend from the inside of the sealing plate 14 to the outside. The positive terminal 30 and the negative terminal 40 are riveted to the periphery of the sealing plate 14 surrounding the terminal lead-out holes 18 and 19 by riveting. At the ends of the positive terminal 30 and the negative terminal 40 on the outer casing 12 side ( Figure 2 The lower end of the component has riveting portions 30c and 40c.

[0076] like Figure 2As shown, the positive terminal 30 is electrically connected to the positive terminal 22 of the electrode assembly 20 via the positive current collector 50 inside the outer casing 12. The negative terminal 40 is electrically connected to the negative terminal 24 of the electrode assembly 20 via the negative current collector 60 inside the outer casing 12. The positive terminal 30 is insulated from the sealing plate 14 by the positive insulating member 70 and the washer 90. The negative terminal 40 is insulated from the sealing plate 14 by the negative insulating member 80 and the washer 90. The positive terminal 30 and the negative terminal 40 are examples of terminals disclosed herein.

[0077] The positive terminal 30 is preferably made of metal, more preferably of, for example, aluminum or an aluminum alloy. The negative terminal 40 is preferably made of metal, more preferably of, for example, copper or a copper alloy. The negative terminal 40 may also be constructed by joining two conductive members together and integrating them. For example, the portion connected to the negative current collector 60 may be made of copper or a copper alloy, while the portion exposed on the outer surface of the sealing plate 14 may be made of aluminum or an aluminum alloy.

[0078] like Figure 1 As shown, plate-shaped positive electrode external conductive member 32 and negative electrode external conductive member 42 are mounted on the outer surface of the sealing plate 14. The positive electrode external conductive member 32 is electrically connected to the positive terminal 30. The negative electrode external conductive member 42 is electrically connected to the negative terminal 40. The positive electrode external conductive member 32 and negative electrode external conductive member 42 are components with busbars attached when multiple batteries 100 are electrically connected to each other. The positive electrode external conductive member 32 and negative electrode external conductive member 42 are preferably made of metal, more preferably of, for example, aluminum or an aluminum alloy. The positive electrode external conductive member 32 and negative electrode external conductive member 42 are insulated from the sealing plate 14 by an external insulating member 92. However, the positive electrode external conductive member 32 and negative electrode external conductive member 42 are not essential and may be omitted in other embodiments.

[0079] Figure 5 This is a schematic perspective view of the electrode assembly 20 mounted on the sealing plate 14. The electrode assembly 20 here has three electrode bodies 20a, 20b, and 20c. Electrode bodies 20a, 20b, and 20c have a pair of rectangular, flat outer surfaces 27 and are formed in a flat hexahedral shape. Electrode bodies 20a and 20c are examples of the first and second electrode bodies disclosed herein. However, the number of electrode bodies disposed inside one outer casing 12 is not particularly limited; it can be two or more, or it can be one. The electrode assembly 20 here is covered by an insulating member 29 made of resin film (see reference). Figure 3 The state configuration covered is located inside the outer casing 12.

[0080] Figure 6 This is a schematic three-dimensional view of the electrode body 20a. Figure 7This is a schematic diagram showing the structure of electrode 20a. Furthermore, the following detailed explanation uses electrode 20a as an example, but the same structure can also be used for electrodes 20b and 20c. Figure 7 As shown, the electrode body 20a has a positive electrode 22 and a negative electrode 24. The electrode body 20a is a flat wound electrode body formed by stacking strip-shaped positive electrode 22 and strip-shaped negative electrode 24 separated by a strip-shaped diaphragm 26 and wound around a winding shaft WL.

[0081] Electrode body 20a is disposed inside the outer casing 12 with its winding axis WL parallel to the long side direction Y. In other words, electrode body 20a is disposed inside the outer casing 12 with its winding axis WL parallel to the bottom wall 12a and orthogonal to the short side wall 12c. The end face of electrode body 20a (in other words, the laminated surface formed by the positive electrode 22 and the negative electrode 24) Figure 7 The end face of the long side in the Y direction is opposite to the short sidewall 12c.

[0082] like Figure 3 As shown, the electrode body 20a has a pair of curved portions 20r facing the bottom wall 12a and the sealing plate 14 of the outer body 12, and a flat portion 20f connecting the pair of curved portions 20r and facing the long side wall 12b of the outer body 12. However, the electrode body 20a may also be a stacked electrode body formed by stacking multiple square (typically rectangular) positive electrodes and multiple square (typically rectangular) negative electrodes in an insulated state.

[0083] like Figure 7 As shown, the positive electrode 22 has a positive current collector 22c and a positive active material layer 22a and a positive protective layer 22p fixed on at least one surface of the positive current collector 22c. However, the positive protective layer 22p is not necessary and can be omitted in other embodiments. The positive current collector 22c is strip-shaped. The positive current collector 22c is made of a conductive metal such as aluminum, aluminum alloy, nickel, or stainless steel. The positive current collector 22c is a metal foil, specifically an aluminum foil. The width of the positive current collector 22c orthogonal to the long side direction Y (see reference). Figure 7 There are no particular limitations as long as the effect of the technology disclosed herein can be achieved, for example, 0.5 mm or more is preferred.

[0084] At one end of the positive current collector 22c along the long side direction Y ( Figure 7 Multiple positive electrode tabs 22t are provided at the left end. The multiple positive electrode tabs 22t are respectively oriented towards one side of the long side direction Y ( Figure 7The positive electrode tabs 22t protrude from the left side of the diaphragm 26. Multiple positive electrode tabs 22t are spaced apart (intermittently) along the long side of the positive electrode 22. Each positive electrode tab 22t is trapezoidal. The positive electrode tabs 22t are part of the positive current collector 22c and are made of metal foil (aluminum foil, aluminum alloy foil, etc.). The positive electrode tabs 22t are the portion of the positive current collector 22c where the positive active material layer 22a and the positive protective layer 22p are not formed (exposed portion of the current collector). However, the positive electrode tabs 22t can also be a different component from the positive current collector 22c. Additionally, the positive electrode tabs 22t can be located at the other end in the long side direction Y. Figure 7 (The right end), or can be set at both ends of the long side Y direction respectively.

[0085] like Figure 7 As shown, multiple positive electrode tabs 22t are located at one end of the long side Y direction ( Figure 7 The left end of each positive electrode tab 22t, i.e., the short sidewall side of one of the pair of short sidewalls 12c (second sidewalls), is stacked to form a positive electrode tab assembly 23. The outer ends of the plurality of positive electrode tabs 22t are bent along the short sidewall 12c. The positive electrode tab assembly 23 is electrically connected to the positive terminal 30 via the positive current collector 50. Preferably, the plurality of positive electrode tabs 22t are bent and joined to the electrode body side surface in the second positive current collector 52 (described later) to be electrically connected to the positive terminal 30. Additionally, as... Figure 4 As shown, the preferred positive electrode tabs 23 are joined together on the flat outer surface side of one of a pair of flat outer surfaces 27. The dimensions of the plurality of positive electrode tabs 22t (length in the long side direction Y and width orthogonal to the long side direction Y) are shown in [reference]. Figure 7 The connection between the positive electrode current collector 50 and the electrode can be considered, and adjusted appropriately, for example, according to its formation position. The width of the positive electrode tab 22t, orthogonal to the long side direction Y, is not particularly limited as long as it achieves the effect of the technology disclosed herein; it is preferably 3μm to 50μm, more preferably 5μm to 30μm, and particularly preferably 10μm to 20μm. The plurality of positive electrode tabs 22t are here made to have different sizes from each other so that the outer ends are aligned when bent. The positive electrode tab group 23 is an example of the electrode tab group disclosed herein.

[0086] like Figure 7As shown, the positive electrode active material layer 22a is arranged in a strip shape along the long side of the strip-shaped positive electrode current collector 22c. The positive electrode active material layer 22a contains a positive electrode active material (such as a lithium transition metal composite oxide, such as a lithium nickel cobalt manganese composite oxide) capable of reversibly absorbing and releasing charge carriers. When the total solid content of the positive electrode active material layer 22a is set to 100% by mass, the positive electrode active material can account for approximately 80% by mass or more, typically 90% by mass or more, for example, 95% by mass or more. The positive electrode active material layer 22a may also contain any components other than the positive electrode active material, such as conductive materials, binders, various additives, etc. As a conductive material, carbon materials such as acetylene black (AB) can be used, for example. As a binder, polyvinylidene fluoride (PVdF) can be used, for example.

[0087] like Figure 7 As shown, the positive electrode protective layer 22p is disposed in the boundary portion between the positive electrode current collector 22c and the positive electrode active material layer 22a in the long side direction Y. The positive electrode protective layer 22p is disposed at one end of the positive electrode current collector 22c in the long side direction Y. Figure 7 (The left end). However, the positive electrode protective layer 22p can also be provided at both ends in the long side direction Y. The positive electrode protective layer 22p is provided in a strip shape along the positive electrode active material layer 22a. The positive electrode protective layer 22p contains inorganic filler (e.g., alumina). When the total solid content of the positive electrode protective layer 22p is set to 100% by mass, the inorganic filler can account for approximately 50% by mass or more, typically 70% by mass or more, for example 80% by mass or more. The positive electrode protective layer 22p can contain any component other than the inorganic filler, such as conductive materials, binders, various additives, etc. The conductive materials and binders can be the same as those exemplified as materials that can be included in the positive electrode active material layer 22a.

[0088] like Figure 7 As shown, the negative electrode 24 has a negative electrode current collector 24c and a negative electrode active material layer 24a fixed on at least one surface of the negative electrode current collector 24c. The negative electrode current collector 24c is strip-shaped. The negative electrode current collector 24c is made of a conductive metal such as copper, copper alloy, nickel, or stainless steel. The negative electrode current collector 24c is a metal foil, specifically a copper foil. The width of the negative electrode current collector 24c orthogonal to the long side direction Y (see reference). Figure 7 There are no particular limitations as long as the effect of the technology disclosed herein can be achieved, for example, 0.5 mm or more is preferred.

[0089] At one end of the negative current collector 24c along the long side direction Y ( Figure 7 Multiple negative electrode tabs 24t are provided at the right end. These multiple negative electrode tabs 24t face the side along the long side Y ( Figure 7The right side of the diaphragm 24 protrudes. Multiple negative electrode tabs 24t protrude more than the diaphragm 26 in the long side direction Y. The multiple negative electrode tabs 24t are spaced apart (intermittently) along the long side direction of the negative electrode 24. Each of the multiple negative electrode tabs 24t is trapezoidal. The negative electrode tabs 24t are part of the negative current collector 24c and are made of metal foil (copper foil, copper alloy, etc.). The negative electrode tabs 24t are the portion of the negative current collector 24c where the negative electrode active material layer 24a is not formed (exposed current collector portion). However, the negative electrode tabs 24t can also be components different from the negative current collector 24c. Additionally, the negative electrode tabs 24t can be located at the other end in the long side direction Y. Figure 7 (The left end), or can be set at both ends of the long side Y direction respectively.

[0090] like Figure 7 As shown, multiple negative electrode tabs 24t are located at one end of the long side in the Y direction ( Figure 7 The right end of the negative electrode tabs 24t, i.e., the other short sidewall of one of the pair of short sidewalls 12c (second sidewalls), is stacked to form a negative electrode tab assembly 25. The outer ends of the plurality of negative electrode tabs 24t are bent in such a way that they extend along the short sidewall 12c. The negative electrode tab assembly 25 is electrically connected to the negative terminal 40 via the negative electrode current collector 60. Preferably, the plurality of negative electrode tabs 24t are bent and engaged with the electrode body side surface in the negative electrode second current collector 62 (described later) to be electrically connected to the negative terminal 40. Additionally, as... Figure 4 As shown, the preferred negative electrode tab assembly 25 is joined in a state where it converges on the flat outer surface side of one of a pair of flat outer surfaces 27. The dimensions of the plurality of negative electrode tabs 24t (length in the long side direction Y and width orthogonal to the long side direction Y) are shown in the figure. Figure 7 The connection between the negative electrode current collector 60 and the negative electrode tab 24t can be considered, and adjusted appropriately, for example, according to its formation position. The width of the negative electrode tab 24t, orthogonal to the long side direction Y, is not particularly limited as long as it achieves the effect of the technology disclosed herein; it is preferably 3μm to 50μm, more preferably 5μm to 30μm, and particularly preferably 5μm to 20μm. The plurality of negative electrode tabs 24t are here made to have different sizes from each other so that the outer ends are aligned when bent. The negative electrode tab assembly 25 is an example of the electrode tab assembly disclosed herein.

[0091] The negative electrode active material layer 24a is arranged in a strip shape along the long side of the strip-shaped negative electrode current collector 24c. The negative electrode active material layer 24a contains a negative electrode active material (such as a carbon material like graphite) capable of reversibly absorbing and releasing charge carriers. When the total solid content of the negative electrode active material layer 24a is set to 100% by mass, the negative electrode active material can account for approximately 80% by mass or more, typically 90% by mass or more, for example, 95% by mass or more. The negative electrode active material layer 24a may also contain any components other than the negative electrode active material, such as binders, dispersants, and various additives. For example, rubbers such as styrene-butadiene rubber (SBR) can be used as binders. For example, cellulose-based materials such as carboxymethyl cellulose (CMC) can be used as dispersants.

[0092] The separator 26 is a component that insulates the positive electrode active material layer 22a of the positive electrode 22 from the negative electrode active material layer 24a of the negative electrode 24. As the separator 26, a porous resin sheet made of polyolefin resin such as polyethylene (PE) or polypropylene (PP) is preferred. It should be noted that a heat resistance layer (HRL) containing inorganic fillers may also be provided on the surface of the separator 26. Examples of inorganic fillers that can be used include alumina, boehmite, aluminum hydroxide, and titanium dioxide.

[0093] The electrolyte can be the same as before, with no particular restrictions. For example, the electrolyte may be a non-aqueous electrolyte containing a non-aqueous solvent and a supporting electrolyte. Non-aqueous solvents may include carbonates such as ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate. Supporting electrolytes may be fluorinated lithium salts such as LiPF6. However, the electrolyte may also be integrated with the electrode assembly 20 in a solid form (solid electrolyte).

[0094] The positive current collector 50 forms a conductive path that electrically connects the positive electrode tab group 23, composed of multiple positive electrode tabs 22t, to the positive terminal 30. For example... Figure 2 As shown, the positive electrode current collector 50 includes a first positive electrode current collector 51 disposed between the sealing plate 14 and the electrode body 20a, and a second positive electrode current collector 52 connected to the positive electrode tab assembly 23. The first positive electrode current collector 51 and the second positive electrode current collector 52 may also be made of the same type of metal as the positive electrode current collector 22c, such as conductive metals like aluminum, aluminum alloy, nickel, and stainless steel.

[0095] Figure 8 It is shown schematically. Figure 2 A magnified cross-sectional view of the vicinity of the positive end 30. Figure 9 This is a schematic perspective view of the sealing plate 14. Figure 10 It is Figure 9 A 3D view of the sealing plate turned upside down. Figure 10 The inner side of the outer casing 12 of the sealing plate 14 is shown. Figures 8-10 As shown, the positive electrode first current collector 51 is mounted on the inner surface of the sealing plate 14. The positive electrode first current collector 51 is an example of the current collector disclosed herein. The positive electrode first current collector 51 has a first region 51a and a second region 51b. The positive electrode first current collector 51 can be formed by bending a single component, for example, through stamping, or by integrating multiple components together through welding. Here, the positive electrode first current collector 51 is fixed to the sealing plate 14 by riveting.

[0096] The first region 51a is located between the sealing plate 14 and the electrode assembly 20. The first region 51a extends along the long side direction Y. The first region 51a extends horizontally along the inner surface of the sealing plate 14. A positive electrode insulating member 70 is disposed between the sealing plate 14 and the first region 51a. The first region 51a is insulated from the sealing plate 14 by the positive electrode insulating member 70. The first region 51a is electrically connected to the positive terminal 30 by riveting. In the first region 51a, a through hole 51h extending in the vertical direction Z is formed at a position corresponding to the terminal lead-out hole 18 of the sealing plate 14. The second region 51b is located between the short sidewall 12c of the outer casing 12 and the electrode assembly 20. The second region 51b extends from one end of the first region 51a along the long side direction Y ( Figure 8 The left end of the second region 51b extends toward the short sidewall 12c of the outer body 12. The second region 51b extends along the vertical direction Z.

[0097] The positive electrode second current collector 52 extends along the short sidewall 12c of the outer casing 12. For example... Figure 6 As shown, the second positive electrode current collector 52 has a current collector plate connection portion 52a, an inclined portion 52b, and an electrode tab connection portion 52c. The current collector plate connection portion 52a is the part that is electrically connected to the first positive electrode current collector 51. The current collector plate connection portion 52a extends along the vertical direction Z. The current collector plate connection portion 52a is arranged substantially perpendicular to the winding axis WL of the electrode bodies 20a, 20b, and 20c. A recess 52d with a thickness thinner than its surroundings is provided in the current collector plate connection portion 52a. A through hole 52e extending along the short side direction X is provided in the recess 52d. A connection portion with the first positive electrode current collector 51 is formed in the through hole 52e. The connection portion is, for example, a welded joint formed by welding such as ultrasonic welding, resistance welding, or laser welding. A fuse may also be provided in the second positive electrode current collector 52.

[0098] The tab connection portion 52c is a part attached to the positive electrode tab group 23 and electrically connected to the multiple positive electrode tabs 22t. For example... Figure 5As shown, the tab joint 52c extends along the vertical direction Z. The tab joint 52c is arranged substantially perpendicular to the winding axis WL of the electrode bodies 20a, 20b, and 20c. The surface of the tab joint 52c that connects to the plurality of positive electrode tabs 22t is arranged substantially parallel to the short sidewall 12c of the outer casing 12. Figure 4 As shown, a joint J with the positive electrode tab assembly 23 is formed at the tab joint 52c. The joint J is, for example, a welded joint formed by welding multiple positive electrode tabs 22t in an overlapping state using ultrasonic welding, resistance welding, laser welding, or the like. The welded joint is configured such that the multiple positive electrode tabs 22t are closer to one side of the electrode bodies 20a, 20b, 20c in the short side direction X. This allows for more appropriate bending of the multiple positive electrode tabs 22t and stable formation. Figure 4 The positive electrode tab group 23 has a curved shape as shown.

[0099] The inclined portion 52b is the part that connects the lower end of the current collector plate connecting portion 52a to the upper end of the electrode joint portion 52c. The inclined portion 52b is inclined relative to the current collector plate connecting portion 52a and the electrode joint portion 52c. The inclined portion 52b connects the current collector plate connecting portion 52a and the electrode joint portion 52c in such a way that the current collector plate connecting portion 52a is located closer to the center side of the electrode joint portion 52c in the long side direction Y. As a result, the housing space of the electrode body assembly 20 can be expanded, and the energy density of the battery 100 can be increased. The lower end of the inclined portion 52b (in other words, the end on the bottom wall 12a side of the outer casing 12) is preferably located below the lower end of the positive electrode tab assembly 23. As a result, multiple positive electrode tabs 22t can be bent more appropriately and formed stably. Figure 4 The positive electrode tab group 23 has a curved shape as shown.

[0100] The negative electrode current collector 60 forms a conductive path that electrically connects the negative electrode tab group 25, which consists of multiple negative electrode tabs 24t, to the negative terminal 40. For example... Figure 2 As shown, the negative electrode current collector 60 includes a first negative electrode current collector 61 disposed between the sealing plate 14 and the electrode body 20a, and a second negative electrode current collector 62 connected to the negative electrode tab assembly 25. The first negative electrode current collector 61 is an example of the current collector disclosed herein. The first negative electrode current collector 61 and the second negative electrode current collector 62 may also be made of the same type of metal as the negative electrode current collector 24c, such as copper, copper alloy, nickel, stainless steel, or other conductive metals. The structure of the first negative electrode current collector 61 and the second negative electrode current collector 62 may be the same as that of the first positive electrode current collector 51 and the second positive electrode current collector 52 of the positive electrode current collector 50.

[0101] like Figure 10As shown, the negative electrode first current collector 61 has a first region 61a and a second region 61b. A negative electrode insulating member 80 is disposed between the sealing plate 14 and the first region 61a. The first region 61a is insulated from the sealing plate 14 by the negative electrode insulating member 80. In the first region 61a, a through hole 61h is formed at a position corresponding to the terminal lead-out hole 19 of the sealing plate 14, extending in the vertical direction Z. Figure 6 As shown, the second negative electrode current collector 62 has a current collector plate connecting portion 62a, an inclined portion 62b, and an electrode tab joining portion 62c attached to the negative electrode tab assembly 25 and electrically connected to the plurality of negative electrode tabs 24t. The current collector plate connecting portion 62a has a recess 62d that connects to the electrode tab joining portion 62c. A through hole 62e extending along the short side direction X is provided in the recess 62d.

[0102] The positive electrode insulating member 70 is a member inside the battery casing 10 that insulates the sealing plate 14 from the positive electrode first current collector 51. The positive electrode insulating member 70 is, for example, made of a resin material that has resistance to and electrical insulation against the electrolyte used and is capable of elastic deformation. The positive electrode insulating member 70 is preferably made of, for example, a polyolefin resin such as polypropylene (PP), a fluorinated resin such as tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA), or polyphenylene sulfide (PPS). Figure 2 As shown, the positive electrode insulating member 70 has a base portion 70a and a protrusion 70b. The base portion 70a and the protrusion 70b are integrally formed here.

[0103] The base portion 70a is disposed in the vertical direction Z between the sealing plate 14 and the first region 51a of the positive electrode first current collector 51. The base portion 70a extends horizontally along the first region 51a of the positive electrode first current collector 51. The base portion 70a has a through hole (not shown) extending in the vertical direction Z. The through hole is formed at a position corresponding to the terminal lead-out hole 18 of the sealing plate 14.

[0104] The protrusions 70b protrude towards the electrode assembly 20 from the base portion 70a. For example... Figure 10 As shown, in the long side direction Y, the protrusion 70b is located on the central side closer to the sealing plate 14 than the base portion 70a. Figure 10 (The position to the right of). Figure 3 As shown, the protrusion 70b faces the curved portion 20r of the electrode bodies 20a, 20b, and 20c that constitute the electrode body assembly 20.

[0105] like Figure 2As shown, the negative electrode insulating member 80 is symmetrically arranged with respect to the long side direction Y of the electrode body assembly 20 with respect to the positive electrode insulating member 70. The specific structure of the negative electrode insulating member 80 can be the same as that of the positive electrode insulating member 70. The negative electrode insulating member 80 here, like the positive electrode insulating member 70, has a base portion 80a and a protrusion 80b disposed between the sealing plate 14 and the negative electrode first current collector 61.

[0106] like Figure 5 As shown, in the battery 100 of this embodiment, the fixing member 1 is arranged in a "コ" shape, covering the positive electrode second current collector 52 of the three electrode bodies 20a, 20b, and 20c from the flat outer surface 27a to the flat outer surface 27f. By fixing the electrode bodies 20a, 20b, and 20c with the fixing member 1 in this way, movement of the electrode body 20b in the long side direction can be more appropriately suppressed. In addition, the fixing member 1 of this embodiment is arranged to cover the three joint portions of the positive electrode 1 current collector 51 and the positive electrode second current collector 52. By fixing the electrode body assembly 20 relative to the position near the sealing plate 14 in the positive electrode current collector 50 in this way, movement of the electrode body assembly 20 in the long side direction can be more appropriately suppressed.

[0107] As the fixing member 1, a member having a substrate and an adhesive layer formed on the substrate is preferably used. Examples of the substrate include polyethylene (PE), polypropylene (PP), polyester, nylon, vinyl chloride, Teflon (registered trademark), polyimide, Capton (registered trademark), polyphenylene sulfide, and polyethylene naphthalate. The thickness of the substrate is not particularly limited as long as it achieves the effect of the technology disclosed herein, and is approximately 5 μm to 100 μm, preferably 10 μm to 50 μm. Furthermore, examples of materials constituting the adhesive layer include acrylic adhesives, silicone adhesives, and rubber adhesives. The adhesive layer preferably has adhesive properties at room temperature (typically around 20°C). The thickness of the adhesive layer is not particularly limited as long as it achieves the effect of the technology disclosed herein, and is approximately 5 μm to 100 μm, preferably 5 μm to 20 μm.

[0108] like Figure 3As shown, in the battery 100 of this embodiment, an insulating member 29 is disposed within the battery casing 10 between the long sidewall 12b (first sidewall) facing the flat outer surface 27a and the flat outer surface 27a, and between the long sidewall of the other of the pair of long sidewalls 12b and the flat outer surface 27f. Furthermore, the coefficient of friction of the electrode bodies 20a, 20b, and 20c (i.e., the coefficient of friction of the flat outer surfaces 27b and 27c, and the flat outer surfaces 27d and 27e; hereinafter also referred to as coefficient of friction A) is greater than the coefficient of friction of the insulating member 29a and the flat outer surface 27a and the coefficient of friction of the insulating member 29b and the flat outer surface 27f (hereinafter also referred to as coefficient of friction B). According to this structure, movement in the long side direction of the electrode body assembly 20 is suppressed, which is therefore preferable. Here, the coefficients of friction A and B can be, for example, the coefficients of friction measured based on the JIS K7125 standard. Furthermore, the difference between the friction coefficients A and B can be approximately 0.1 to 0.9, preferably approximately 0.5 to 0.8, but is not limited thereto. It should be noted that, as a method to achieve the aforementioned difference between the friction coefficients A and B, one approach is to appropriately select the materials constituting the insulating member 29 and the flat outer surface 27. Those skilled in the art can easily implement this material selection by conducting preliminary tests, etc.

[0109] Furthermore, in the battery 100 of this embodiment, the coefficient of friction of electrode bodies 20a and 20b (i.e., the coefficient of friction of flat outer surfaces 27b and 27c) and the coefficient of friction of electrode bodies 20b and 20c (i.e., the coefficient of friction of flat outer surfaces 27d and 27e) (hereinafter also referred to as coefficient of friction C) are greater than the coefficient of friction of insulating member 29 and long sidewall 12b (i.e., the coefficient of friction of insulating member 29a and long sidewall 12b, and the coefficient of friction of insulating member 29b and long sidewall 12b; hereinafter also referred to as coefficient of friction D). According to this structure, movement in the long side direction of electrode body assembly 20 is suppressed, which is therefore preferable. Here, the coefficients of friction C and D can be, for example, the coefficients of friction measured based on JIS K7125. Furthermore, the difference between the coefficients of friction C and D can be approximately 0.1 to 0.9, preferably approximately 0.5 to 0.8, but is not limited thereto. It should be noted that, as a method to achieve the aforementioned difference in the coefficients of friction C and D, one can exemplify this by appropriately selecting the materials constituting the insulating member 29, the long sidewall 12b, and the flat outer surface 27. Those skilled in the art can easily implement this material selection by conducting preliminary tests, etc.

[0110] like Figure 5As shown, in the battery 100 of this embodiment, no fixing member 1 is provided between electrode bodies 20a and 20b, or between electrode bodies 20b and 20c. With this structure, the cumulative thickness of the electrode body assembly 20 can be reduced, thus mitigating the pressure distribution of each electrode body constituting the electrode body assembly 20. Therefore, uneven reaction in each electrode body constituting the electrode body assembly 20 can be appropriately suppressed, which is preferable.

[0111] <Manufacturing Method of Battery 100>

[0112] The manufacturing method of battery 100 is characterized by having the aforementioned fixing member 1. Other manufacturing processes can be the same as before. In addition to the fixing member 1, battery 100 also includes the aforementioned battery casing 10 (outer body 12 and sealing plate 14), electrode assembly 20 (electrode bodies 20a, 20b, 20c), electrolyte, positive terminal 30, negative terminal 40, positive current collector 50 (positive first current collector 51 and positive second current collector 52), negative current collector 60 (negative first current collector 61 and negative second current collector 62), positive insulating member 70, and negative insulating member 80. It is manufactured, for example, by a manufacturing method including a first mounting step, a second mounting step, an insertion step, and a sealing step. Furthermore, the manufacturing method disclosed herein may further include other steps at any stage.

[0113] In the first installation process, the fabrication Figure 9 , Figure 10 The first composite as shown. Specifically, firstly, a positive terminal 30, a positive first current collector 51, a positive insulating member 70, a negative terminal 40, a negative first current collector 61, and a negative insulating member 80 are installed on the sealing plate 14.

[0114] The positive terminal 30, the first positive current collector 51, and the positive insulating member 70 are fixed to the sealing plate 14, for example, by riveting. Figure 8 As shown, a washer 90 is sandwiched between the outer surface of the sealing plate 14 and the positive terminal 30, and a positive electrode insulating member 70 is sandwiched between the inner surface of the sealing plate 14 and the positive electrode first current collector 51 for riveting. Furthermore, the washer 90 can be made of the same material as the positive electrode insulating member 70. Specifically, before riveting, the positive terminal 30 is inserted sequentially from above the sealing plate 14 into the through hole 90h of the washer 90, the terminal lead-out hole 18 of the sealing plate 14, the through hole 70h of the positive electrode insulating member 70, and the through hole 51h of the positive electrode first current collector 51, protruding downwards from the sealing plate 14. Then, the portion of the positive terminal 30 that protrudes downwards from the sealing plate 14 is riveted to apply a compressive force in the vertical direction Z. Thus, at the top end of the positive terminal 30 ( Figure 2The lower end of the part forms a riveting part 30c.

[0115] Through this riveting process, the washer 90, sealing plate 14, positive electrode insulating component 70, and positive electrode first current collector 51 are integrally fixed to the sealing plate 14, and the terminal lead-out hole 18 is sealed. Furthermore, the riveting part 30c can also be welded to the positive electrode first current collector 51. This further improves the reliability of conduction.

[0116] The fixing of the negative terminal 40, the first negative current collector 61, and the negative insulating member 80 can be performed in the same manner as the positive terminal side described above. That is, before riveting, the negative terminal 40 is inserted sequentially from above the sealing plate 14 into the through hole of the washer, the terminal lead-out hole 19 of the sealing plate 14, the through hole of the negative insulating member 80, and the through hole of the first negative current collector 61, protruding downwards from the sealing plate 14. Then, the portion of the negative terminal 40 that protrudes downwards from the sealing plate 14 is riveted to apply a compressive force in the vertical direction Z. As a result, at the top end of the negative terminal 40 ( Figure 2 The lower end of the part forms a riveting part 40c.

[0117] Next, the positive electrode external conductive member 32 and the negative electrode external conductive member 42 are installed on the outer surface of the sealing plate 14 via the external insulating member 92. Furthermore, the material of the external insulating member 92 can be the same as that of the positive electrode insulating member 70. Additionally, the positive electrode external conductive member 32 and the negative electrode external conductive member 42 can be installed after the insertion process (e.g., after sealing the injection hole 15).

[0118] In the second installation step, the first composite material produced in the first installation step is used to manufacture... Figure 5 The second composite as shown. That is, the electrode assembly 20 is made integrated with the sealing plate 14. Specifically, firstly, as shown... Figure 6 As shown, three electrode bodies 20a, each equipped with a positive second current collector 52 and a negative second current collector 62, are prepared and arranged as electrode bodies 20a, 20b, and 20c in the short-side direction X. At this time, electrode bodies 20a, 20b, and 20c can all be positioned with the positive second current collector 52 on one side in the long-side direction Y. Figure 5 (on the left side) and the negative electrode second current collector 62 is disposed on the other side in the long side direction Y ( Figure 5 They are arranged side by side on the right side.

[0119] Next, as Figure 4As shown, with the multiple positive electrode tabs 22t bent, the first positive electrode current collector 51 (specifically, the second region 51b) fixed to the sealing plate 14 is joined to the second positive electrode current collector 52 (specifically, the current collector plate connection portion 52a) of the electrode bodies 20a, 20b, and 20c, respectively. Similarly, with the multiple negative electrode tabs 24t bent, the first negative electrode current collector 61 fixed to the sealing plate 14 is joined to the second negative electrode current collector 62 of the electrode bodies 20a, 20b, and 20c, respectively. As a joining method, ultrasonic welding, resistance welding, laser welding, etc., can be used. Welding based on high-energy rays such as lasers is particularly preferred. Through this welding process, joint portions are formed in the recesses 52d of the second positive electrode current collector 52 and the recesses 62d of the second negative electrode current collector 62, respectively.

[0120] Next, as Figure 5 As shown, the fixing member 1 is arranged in a "コ" shape, covering the positive electrode second current collector 52 of the three electrode bodies 20a, 20b, and 20c from the flat outer surface 27a to the flat outer surface 27f. Furthermore, the fixing member 1 can be arranged before the positive electrode first current collector 51 (specifically, the second region 51b) fixed to the sealing plate 14 is joined to the positive electrode second current collector 52 (specifically, the current collector plate connecting portion 52a) of the electrode bodies 20a, 20b, and 20c, respectively. That is, before... Figure 6 In the manner shown, the fixing member 1 can also be configured after the positive electrode tab assembly 23 is bent. Furthermore, from the viewpoint of improving work efficiency, it is more preferable to configure the fixing member 1 at the aforementioned timing.

[0121] In the insertion process, the second composite object, which was created in the second installation process, is housed in the internal space of the outer casing 12. Figure 11 This is a schematic cross-sectional view illustrating the insertion process. Specifically, firstly, an insulating member 29 is prepared by bending an insulating resin sheet (resin film) made of a resin material such as polyethylene (PE) into a bag or box shape. Next, the electrode assembly 20 is housed in the insulating member 29. Then, the electrode assembly 20 covered by the insulating member 29 is inserted into the outer casing 12. If the electrode assembly 20 is heavy, that is, approximately 1 kg or more, for example, 1.5 kg or more, and further 2 to 3 kg, the electrode assembly 20 is inserted into the outer casing 12 in a manner where the long sidewall 12b of the outer casing 12 intersects the direction of gravity (the outer casing 12 is placed laterally).

[0122] In the sealing process, the sealing plate 14 is joined to the edge of the opening 12h of the outer casing 12, sealing the opening 12h. The sealing process can be performed simultaneously with the insertion process or after the insertion process. In the sealing process, it is preferable to weld the outer casing 12 to the sealing plate 14. The welding of the outer casing 12 to the sealing plate 14 can be performed, for example, by laser welding. Afterward, electrolyte is injected through the injection hole 15, and the injection hole 15 is blocked with the sealing member 16, thereby sealing the battery 100. As described above, the battery 100 can be manufactured.

[0123] The battery 100 can be used for various purposes, including applications where it may be subjected to external forces such as vibration and impact during use. For example, it is suitable as a power source (drive power supply) for motors mounted on moving bodies (typically passenger cars, trucks, etc.). There are no particular limitations on the type of vehicle; examples include plug-in hybrid electric vehicles (PHEVs), hybrid electric vehicles (HEVs), and battery electric vehicles (BEVs). The battery 100 can also be used as a battery pack formed by arranging multiple batteries 100 in a predetermined arrangement direction and applying load from the arrangement direction using a constraint mechanism.

[0124] The above description illustrates several embodiments of this disclosure, but these embodiments are merely examples. This disclosure can also be implemented in various other ways. This disclosure can be implemented based on the content disclosed in this specification and common technical knowledge in the art. The technology described in the claims includes technologies obtained by various modifications and alterations to the embodiments illustrated above. For example, a portion of the above embodiments can be replaced with other modifications, and other modifications can be added to the above embodiments. Furthermore, if a technical feature is not described as an essential technical feature, it can be appropriately deleted.

[0125] In the above embodiment, in the electrode body 20a, both the positive electrode tab group 23 and the negative electrode tab group 25 are joined together on the flat outer surface 27a side (see reference). Figure 4 However, this is not a limitation. For example, in electrode body 20a, the positive electrode tab group 23 may be joined in a state where it is gathered on the flat outer surface 27a side, and the negative electrode tab group 25 may be joined in a state where it is gathered on the flat outer surface 27b side. Alternatively, the positive electrode tab group 23 (negative electrode tab group 25) may also be joined in a state where they are separately gathered on the flat outer surface 27a side and the flat outer surface 27b side. The same applies to electrode bodies 20b and 20c.

[0126] In the above embodiment, the number of bends of the positive electrode tab group 23 and the negative electrode tab group 25 in the electrode body 20a is set to 1 (refer to...). Figure 4However, this is not a limitation. For example, the number of bends can also be set to multiple. The same applies to electrode bodies 20b and 20c.

[0127] In the above embodiment, the length of the fixing member 1 in the Y direction in the flat outer surface 27a of the electrode body 20a is arranged such that it is about 1 / 20 of the length La in the Y direction of the flat outer surface 27a (see reference). Figure 5 However, this is not a limitation. For example, the length of the fixing member in the Y direction can be approximately (1 / 30)La or more, and from the viewpoint of improving fixing strength, it is preferable to be (1 / 20)La or more, more preferably (1 / 10)La or more, and even more preferably (1 / 5)La or more. In addition, the length of the fixing member in the Y direction can be La, or it can be (3 / 4)La or less, (1 / 2)La or less, or (1 / 3)La or less. The length of the fixing member 1 in the Y direction disposed on the flat outer surface 27f is also the same.

[0128] In the above embodiment, the fixing member 1 was described in a "ko" shape, covering the positive electrode second current collector 52 of the three electrode bodies 20a, 20b, and 20c from the flat outer surface 27a to the flat outer surface 27f. However, this is not a limitation. For example, the fixing member could also be arranged in a "ko" shape, covering the negative electrode second current collector 62 of the three electrode bodies 20a, 20b, and 20c from the flat outer surface 27a to the flat outer surface 27f. It should be noted that, compared to the case where the fixing member is arranged in a "ko" shape on the positive electrode side (i.e., the arrangement described above), the case where the fixing member is arranged in a "ko" shape on the negative electrode side (i.e., the arrangement described later) is preferable because the electrode bodies are fixed to the negative electrode side, thus preventing the positive electrode tab assembly from bending and stretching, which is easily bent. Alternatively, for example, the fixing member can be disposed from the flat outer surface 27a of the electrode body 20a to the positive electrode second current collector 52 of the electrode body 20a and the positive electrode second current collector 52 of the electrode body 20b, and from the flat outer surface 27f of the electrode body 20c to the negative electrode second current collector 62 of the electrode body 20c and the negative electrode current collector 62 of the electrode body 20b. Furthermore, these are just examples; various other arrangements are also possible.

[0129] In the above embodiment, the fixing member 1 was described as being arranged to cover the three joints between the positive electrode 1 current collector 51 and the positive electrode second current collector 52, but this is not a limitation. For example, as Figure 12 As shown, the fixing member 1a can also be arranged in a "ko" shape to cover the area near the center of the positive electrode second current collector 52 of the three electrode bodies 20a, 20b, and 20c. Alternatively, for example, as... Figure 13As shown, the fixing member 1b can also be arranged in a "コ" shape to cover the area below the positive electrode second current collector 52 of the three electrode bodies 20a, 20b, and 20c. Furthermore, it can be appropriately combined... Figure 5 , Figure 12 , Figure 13 This is implemented in a certain way. Additionally, in situations such as... Figure 12 , Figure 13 When the fixing member is configured as shown, it is preferable not to cover the tab joint 52c. Furthermore, while the above description focuses on the positive electrode second collector 52, the same applies to the negative electrode second collector 62. Moreover, this is just one example; various other configurations are also possible.

[0130] In the above embodiment, the fixing member 1 is also disposed on the positive electrode second current collector 52 of the electrode body 20b, but it is not limited to this. For example, as Figure 14 As shown, the fixing member 1c can also be disposed from the flat outer surface 27a of the electrode body 20a to the positive electrode second current collector 52 of the electrode body 20a, and from the flat outer surface 27f of the electrode body 20c to the positive electrode second current collector 52 of the electrode body 20c. In this case, it is preferable to suppress the movement of the electrode body 20b in the long side direction by friction generated between the flat outer surfaces 27b and 27c and between the flat outer surfaces 27d and 27e.

[0131] Alternatively, as with electrode bodies 20a, 20b, and 20c in this embodiment, in the case where the flat outer surface is composed of a diaphragm 26 (see [reference]). Figure 7 To suppress the movement of electrode body 20b along its long side, an adhesive layer may be provided on the flat outer surface (i.e., the outermost surface of the diaphragm) of electrode bodies 20a, 20b, and 20c. An example of such an adhesive layer is a layer containing PVdF. Alternatively, the adhesive layer may also contain other components such as inorganic fillers. Examples of such inorganic fillers include alumina, boehmite, aluminum hydroxide, and titanium dioxide. Here, when the total composition of the adhesive layer is set to 100% by mass, the PVdF content can be approximately 5% by mass or more, preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more. Furthermore, the PVdF content can be 100% by mass, for example, 90% by mass or less, preferably 80% by mass or less.

[0132] In addition, as a preferred embodiment, examples can be listed. Figure 15 The method of configuring the fixed components as shown. In Figure 15In this configuration, fixing members 1d and 1e are respectively arranged so that they cover the vicinity and below the center of the positive electrode second current collector 52 of the three electrode bodies 20a, 20b, and 20c from the flat outer surface 27a to the flat outer surface 27f. Furthermore, fixing members 1f and 1g are respectively arranged so that they cover the vicinity and below the center of the negative electrode second current collector 62 of the three electrode bodies 20a, 20b, and 20c from the flat outer surface 27a to the flat outer surface 27f. Additionally, auxiliary fixing members 1h, 1i, and 1j are arranged in a "コ" shape from the flat outer surface 27a to the flat outer surface 27f, excluding the positive electrode second current collector 52 and the negative electrode second current collector 62. This effectively suppresses movement of the electrode body 20b along its long side. Furthermore, in... Figure 15 In this configuration, fixing members 1d, 1e, 1h and fixing members 1f, 1g, 1i are arranged symmetrically with respect to the centerline CL of the central portion in the Y direction passing through the battery casing 10, but are not limited to this arrangement; they may also be arranged asymmetrically with respect to CL. Furthermore, in Figure 15 In the middle, the auxiliary fixing member 1j is positioned at the center of La, but is not limited to this; it can also be appropriately positioned on the left or right ( Figure 15 The left and right directions are staggered. For example... Figure 15 As shown, from the viewpoint of effectively suppressing movement along the long side of the electrode body 20b, it is preferable to have all auxiliary fixing members 1h, 1i, and 1j configured, but this can be appropriately reduced. Furthermore, although in Figure 15 It is not recorded in the document, but the fixing member can also be arranged in a "ko" shape so that the sealing plate 14 is covered from the flat outer surface 27a to the flat outer surface 27f.

[0133] In the above embodiment, a battery 100 having three electrode bodies has been described, but it is not limited to this. For example, multiple (i.e., two or more) electrode bodies may be arranged between electrode bodies 20a and 20c. In this case, it is preferable to fix electrode body 20a, the multiple electrode bodies arranged between electrode bodies 20a and 20c, and electrode body 20c. As an example of a method for fixing the electrode bodies to each other, a method in which the fixing members are arranged in a "コ" shape so as to cover the positive electrode second current collector and / or negative electrode second current collector of each electrode body from the flat outer surface 27a to the flat outer surface 27f. Alternatively, an adhesive layer as described above may be provided on the flat outer surface of each electrode body. As a result, movement in the long side direction of each electrode body can be appropriately suppressed.

[0134] In the above embodiment, a battery 100 having three electrodes has been described, but it is not limited to this. For example, a battery may have only one electrode. For example, when the battery has an electrode 20a, the fixing member can be arranged in an L-shape from the flat outer surface 27a to the positive electrode second current collector 52. Alternatively, the fixing member can be arranged in a "ko" shape from the flat outer surface 27a to the flat outer surface 27b. Here, when the fixing member is arranged in a state of tension such as a "ko", the electrode 20a is firmly fixed relative to the positive electrode second current collector 52, which is therefore preferable. In addition, the positive electrode second current collector 52 has been described above, but the same applies to the negative electrode second current collector 62. Furthermore, these are just examples, and various other arrangements are possible.

Claims

1. A battery comprising: a first electrode body in the shape of a flattened hexahedron, the first electrode body including a positive electrode and a negative electrode, and having a pair of rectangular flat outer surfaces; and a battery casing housing the first electrode body, wherein... The battery housing includes: an outer body having a bottom wall, a pair of first side walls extending from the bottom wall and facing each other, a pair of second side walls extending from the bottom wall and facing each other, and an opening facing the bottom wall; and a sealing plate, which seals the opening. The sealing plate is equipped with a positive terminal and a negative terminal. A positive electrode tab assembly comprising multiple positive electrode tabs is disposed on one of the pair of second sidewalls. A negative electrode tab assembly comprising multiple negative electrode tabs is disposed on the second side wall of the other of the pair of second side walls. The positive electrode tab assembly and the positive terminal are electrically connected via a positive current collector. The positive electrode tab assembly engages with the positive current collector while being bent in a manner that extends along the second sidewall of one of the pair of second sidewalls. In the positive electrode current collector, the region facing one of the second sidewalls of the pair of second sidewalls includes a first region and a second region. In a direction perpendicular to the second sidewall of one of the pair of second sidewalls, the first region is positioned further away from the second sidewall of one of the pair of second sidewalls than the second region. The positive current collector also includes a fifth region. In a direction perpendicular to the bottom wall, the first region is located closer to the sealing plate than the second region. The fifth region connects the first region and the second region. The positive current collector is bent between the first region and the fifth region, and between the second region and the fifth region, respectively. The negative electrode tab assembly and the negative terminal are electrically connected via a negative electrode current collector. The negative electrode tab assembly engages with the negative electrode current collector in a bent state, extending along the second sidewall of the other of the pair of second sidewalls. In the negative electrode current collector, the region facing the other of the pair of second sidewalls includes a third region and a fourth region. In a direction perpendicular to the second sidewall of the other of the pair of second sidewalls, the third region is positioned further away from the second sidewall of the other of the pair of second sidewalls than the fourth region. The negative electrode current collector also includes a sixth region. In a direction perpendicular to the bottom wall, the third region is located closer to the sealing plate than the fourth region. The sixth region connects the third region and the fourth region. The negative electrode current collector is bent between the third region and the sixth region, and between the fourth region and the sixth region, respectively. Here, a fixing member is disposed from at least one of the flat outer surfaces of the pair of flat outer surfaces to the first region of the positive current collector or the third region of the negative current collector.

2. The battery according to claim 1, wherein, The fixing member includes a substrate and an adhesive layer formed on the substrate.

3. The battery according to claim 1 or 2, wherein, The positive electrode tabs are engaged with the positive current collector when they are gathered on the flat outer surface side of one of the pair of flat outer surfaces. The negative electrode tabs are engaged with the negative electrode current collector when they are gathered on the flat outer surface side of one of the pair of flat outer surfaces.

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