Power storage device and method for manufacturing power storage device

Abstract

The present disclosure relates to a power storage device and a manufacturing method of a power storage device. A technique capable of suppressing the rolling of a separator and shortening the liquid injection time is provided. In a preferred embodiment of the manufacturing method disclosed herein, a preparation step (S1) of preparing a battery assembly and a liquid injection step (S2) of injecting an electrolyte into the battery assembly are included. In the liquid injection step (S2), the battery assembly is placed with a seal plate having a liquid injection hole formed therein facing upward, and the electrolyte is injected from a liquid injection port inserted into the liquid injection hole.

Description

Technical Field

[0001] This disclosure relates to energy storage devices and methods for manufacturing energy storage devices. Background Technology

[0002] Japanese Patent Application Publication No. 2011-076952 discloses a sealed battery comprising: an outer can; an electrode assembly housed within the outer can and including a positive and a negative electrode; a battery sealing body installed at the opening of the outer can; a safety valve provided at the battery sealing body or the outer can; and a spacer disposed at a position in contact with the electrode assembly. The spacer is characterized in that its surface in contact with the electrode assembly has a planar portion, and this planar portion forms a plurality of through passages.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-076952 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] Furthermore, when batteries are enlarged to increase their capacity in vehicles, the amount of electrolyte injected increases. Especially in large batteries, if electrolyte injection is to be completed within a specified time, the amount of electrolyte injected per unit time needs to be increased.

[0008] Solution for solving the problem

[0009] The method for manufacturing an energy storage device disclosed herein includes: a preparation step for preparing an energy storage device assembly; and an electrolyte injection step for injecting electrolyte into the energy storage device assembly. The energy storage device assembly includes a housing, an electrode body housed within the housing, and a spacer. The housing has a housing space for housing the electrode body and a sidewall with an injection port for injecting the electrolyte. The electrode body has a laminated structure consisting of a sheet-like positive electrode and a sheet-like negative electrode separated by a sheet-like separator. The end faces of the laminated structure are disposed in the housing space facing the sidewall. The spacer is disposed within the housing between the sidewall and the electrode body. A partition wall portion faces the sidewall and separates the housing space from the end space on the sidewall side. The partition wall portion has multiple openings penetrating the partition wall portion. The ratio of the total area of ​​the multiple openings to the area of ​​the injection port (total area of ​​openings / area of ​​injection port) is 22 or more and 49 or less. When the cross-sectional area along the sidewall of the housing is set to 100%, the total area of ​​the plurality of openings is 8% or more. When the cross-sectional area along the sidewall of the housing is set to 100%, the area of ​​the injection hole is 0.2% or more. In the injection process, the energy storage device assembly is placed with the sidewall where the injection hole is formed facing upwards, and the electrolyte is injected through the injection port inserted into the injection hole. According to this structure, even if the injection volume per unit time is increased, for example, the roll-up of the sheet-like diaphragm can be suppressed. In addition, according to this structure, the electrolyte injection time can be shortened.

[0010] The energy storage device disclosed herein includes an electrode body, an electrolyte, a housing for housing the electrode body and the electrolyte, and a spacer. The housing has a housing space for housing the electrode body and a sidewall with an injection port for injecting the electrolyte. The electrode body has a laminated structure consisting of a sheet-like positive electrode and a sheet-like negative electrode separated by a sheet-like separator. The end faces of the laminated structure are disposed in the housing space facing the sidewall. The spacer is disposed within the housing between the sidewall and the electrode body. A partition wall portion faces the sidewall and separates the housing space from the end space on the sidewall side. The partition wall portion has multiple openings penetrating the partition wall portion. The ratio of the total area of ​​the multiple openings to the area of ​​the injection port (total area of ​​openings / area of ​​injection port) is 22 or more and 49 or less. The ratio of the total area of ​​the multiple openings to 8% when the cross-sectional area of ​​the housing along the sidewall is set to 100% is 8% or more. When the cross-sectional area of ​​the housing along the side wall is set to 100%, the area of ​​the injection hole is 0.2% or more. This type of energy storage device is a high-quality energy storage device that suppresses the rolling up of the sheet-like diaphragm. Attached Figure Description

[0011] Figure 1 This is a perspective view schematically illustrating one embodiment of a battery.

[0012] Figure 2 Therefore with Figure 1 A perspective view of a battery in one embodiment from different viewpoints.

[0013] Figure 3 It is a schematic representation Figure 1 A cross-sectional view of the internal structure of a battery.

[0014] Figure 4 This is a perspective view schematically showing the electrode body of a battery according to one embodiment.

[0015] Figure 5 This is a perspective view schematically illustrating a spacer in a battery according to one embodiment.

[0016] Figure 6 This is a schematic enlarged cross-sectional view illustrating the injection of electrolyte into a battery according to one embodiment.

[0017] Figure 7 This is a schematic diagram illustrating the positional relationship between the injection hole and the opening in one embodiment.

[0018] Figure 8 This is a schematic diagram of a sealing plate according to one embodiment, viewed from the top surface.

[0019] Figure 9 This is a flowchart illustrating a method for manufacturing a battery according to one embodiment.

[0020] Figure 10 This is a first schematic diagram illustrating the liquid injection process of one embodiment.

[0021] Figure 11 It is a schematic representation along Figure 10 A schematic diagram of the cross section of line A-A.

[0022] Figure 12 This is a second schematic diagram illustrating the liquid injection process of one embodiment.

[0023] Figure 13 This is a third schematic diagram illustrating the liquid injection process of one embodiment. Detailed Implementation

[0024] Hereinafter, some embodiments of the technology disclosed herein will be described with reference to the accompanying drawings. In the drawings, components and parts that perform the same function are appropriately labeled with the same reference numerals. Furthermore, the dimensional relationships (length, width, thickness, etc.) in the drawings do not reflect actual dimensional relationships. In addition, matters necessary for implementing the technology disclosed herein, other than those specifically mentioned in this specification (e.g., the general structure and manufacturing process of energy storage devices that do not characterize this disclosure), can be understood by those skilled in the art based on prior art. The technology disclosed herein can be implemented based on the content disclosed in this specification and common technical knowledge in the field. Furthermore, the following description is not intended to limit this disclosure to the following methods.

[0025] In this specification, the expression "A~B" indicating a range means "above A and below B". Furthermore, the expression "A~B" includes both "greater than A" and "less than B". In this specification, "energy storage device" refers to a device capable of charging and discharging. Energy storage devices include batteries such as primary batteries and secondary batteries (e.g., non-aqueous electrolyte secondary batteries such as lithium-ion secondary batteries, nickel-metal hydride batteries) and capacitors such as double-layer capacitors (physical batteries). Additionally, "energy storage device assembly" refers to a structure in which the constituent materials of the energy storage device are mechanically and appropriately assembled, and refers to a structure in its state before electrochemical activation treatments such as initial charging treatment are performed. Hereinafter, a lithium-ion secondary battery (hereinafter simply referred to as "battery") as an example of one embodiment of the energy storage device disclosed herein will be described. Furthermore, the following description is not intended to limit the energy storage device to lithium-ion secondary batteries.

[0026] <Battery Structure>

[0027] Hereinafter, the battery 1 of this embodiment will be described. Battery 1 is a battery obtained by the manufacturing method of battery 1 described later. Here, Figure 1 This is a perspective view schematically illustrating one embodiment of battery 1. Figure 2 Therefore with Figure 1 A perspective view of battery 1 in one embodiment from different angles. Figure 3 It is a schematic representation Figure 1 A cross-sectional view of the internal structure of battery 1. Figure 4 This is a perspective view schematically showing the electrode body 30 of the battery 1 according to one embodiment. Furthermore, in Figure 4 For ease of observation, only a portion of the positive electrode 32, negative electrode 34, and diaphragm 36 of the electrode body 30 are described. Figure 5 This is a perspective view schematically showing the spacer 40A of the battery 1 according to one embodiment. Figure 6 This is a schematic enlarged cross-sectional view illustrating the injection of electrolyte E into battery 1 according to one embodiment. Figure 7 This is a schematic diagram illustrating the positional relationship between the injection hole 22 and the openings 43c1 and 43c2 in one embodiment. Furthermore, in Figure 7 For ease of observation, the diagrams of the sealing plate 20A and the positive terminal 50 have been omitted. Figure 8 This is a schematic diagram of a sealing plate according to one embodiment, viewed from the top surface.

[0028] In the accompanying drawings, reference numerals X, Y, and Z represent the long side direction, short side direction, and height direction of battery 1, respectively. Reference numerals X, Y, and Z can also be referred to as the first direction, second direction, and third direction, respectively. However, these directions are determined for ease of explanation. The arrangement of battery 1 is not limited by these directions. Furthermore, the following description focuses on the case where the sidewall is a sealing plate 20A, but it is not intended to limit this disclosure to this arrangement.

[0029] like Figures 1-3 As shown, the battery 1 of this embodiment includes an electrode body 30, an electrolyte E, a casing 70, and spacers 40A and 40B.

[0030] like Figure 3 As shown, the housing 70 is a component that houses the electrode body 30 and the electrolyte E. The housing 70 includes a housing space 3 for housing the electrode body 30 and a sealing plate 20A with an injection hole 22 for injecting the electrolyte E. Figure 3 In the arrangement shown, the shell 70 is a flat, rectangular container that is approximately cuboid in shape. The shell 70 includes a shell body 10 and sealing plates 20A and 20B.

[0031] The main body 10 of the housing has a pair of generally rectangular openings 12a and 12b at both ends in the long side direction X (see reference). Figure 3 A flat, cylindrical component. The main body 10 of the shell has a storage space 3 of the required length along its long side X. Figure 1 and Figure 2 In the illustrated configuration, the housing body 10 includes a pair of first sidewalls 14a and 14c facing each other in the height direction Z and a pair of second sidewalls 14b and 14d facing each other in the short side direction Y. The first sidewalls 14a and 14c and the second sidewalls 14b and 14d are continuous in the circumferential direction, surrounding the periphery of the storage space 3. The housing body 10 can be manufactured, for example, by bending a metal sheet into a cylindrical shape and joining the seams (e.g., by welding). Figure 1 In the configuration shown, the housing body 10 has a welded joint 18 extending along the longitudinal direction X on its first sidewall 14a in the height direction Z. Additionally, in Figure 2In the configuration shown, a thin-walled portion 14c1 is provided on the first sidewall 14c on the opposite side of the height direction Z. The thin-walled portion 14c1 serves as a safety valve that opens when the internal pressure of the storage space 3 becomes too high. The material constituting the housing body 10 is preferably a metallic material such as aluminum, aluminum alloy, iron, or iron alloy.

[0032] like Figure 3 As shown, sealing plates 20A and 20B are a pair of generally rectangular plate-shaped members that block a pair of openings 12a and 12b of the housing body 10. In this embodiment, the openings 12a and 12b on both sides of the housing body 10 are sealed by sealing plates 20A and 20B, thereby constructing the housing 70. The pair of sealing plates 20A and 20B face each other in the long side direction X. Here, sealing plate 20A is installed on one side X1 of the long side direction X of the opening 12a of the housing body 10. In addition, sealing plate 20B is installed on the other side X2 of the long side direction X of the opening 12b of the housing body 10. A positive terminal 50, a liquid injection hole 22, and a sealing plug 24 are provided on sealing plate 20A. In addition, a negative terminal 60 is provided on sealing plate 20B. The materials constituting sealing plates 20A and 20B are preferably the same metal material as the housing body 10 (aluminum, aluminum alloy, iron, iron alloy, etc.).

[0033] The positive terminal 50 is preferably made of metal, more preferably aluminum or an aluminum alloy. Figure 3 As shown, the positive terminal 50 is disposed at the center of the first sidewall 14a of the housing body 10 in the facing direction (height direction Z). The positive terminal 50 has an external positive terminal 52 and an internal positive terminal 54. The external positive terminal 52 protrudes through the sealing plate 20A and extends outside the housing 70. The internal positive terminal 54 is housed inside the housing 70. The internal positive terminal 54 is connected to the electrode tab 30t (positive electrode tab 32t) of the electrode body 30. Furthermore, in this specification, components that form a conductive path from the electrode body 30 inside the housing 70 to the external terminal outside the housing 70 are collectively referred to as "internal conductive members". In the battery 1 of this embodiment, the internal positive conductive member A1 is composed of the internal positive terminal 54 and the positive electrode tab 32t. In addition, as Figure 6 As shown, an insulating member 21 is provided to insulate the positive terminal 50 from the sealing plate 20A. The insulating member 21 can be made of the material used in conventionally known insulating members for this type of battery 1.

[0034] The negative terminal 60 is preferably made of metal, more preferably copper or a copper alloy. Figure 3As shown, the negative terminal 60 is disposed at the center of the first sidewall 14a of the housing body 10 in the facing direction (height direction Z). The negative terminal 60 has an external negative terminal 62 and an internal negative terminal 64. The external negative terminal 62 penetrates the sealing plate 20B and protrudes to the outside of the housing 70. The internal negative terminal 64 is housed inside the housing 70. The internal negative terminal 64 is connected to the electrode tab 30t (negative electrode tab 34t) of the electrode body 30. In the battery 1 of this embodiment, the internal negative conductive member A2 is composed of the internal negative terminal 64 and the negative electrode tab 34t.

[0035] like Figure 6 As shown, the injection hole 22 is an opening that penetrates the sealing plate 20A. The injection hole 22 is used to inject electrolyte E into the interior of the housing 70 (see reference). Figure 3 The injection hole 22 is offset from the positive terminal 50 in the height direction Z to avoid interference with the positive terminal 50. After the electrolyte E is injected into the interior of the housing 70, the injection hole 22 is sealed by the sealing plug 24.

[0036] Electrode 30 is a power generation element in battery 1. For example... Figure 3 As shown, the electrode body 30 is housed inside the housing 70. Specifically, the electrode body 30 is positioned at the center of the longitudinal direction X, between a pair of sealing plates 20A and 20B. Furthermore, the electrode body 30 of this embodiment includes a sheet-shaped positive electrode 32, a sheet-shaped negative electrode 34, and a sheet-shaped diaphragm 36 (see reference). Figure 4 Although not specifically limited, "sheet-like" can refer to, for example, a thickness in the range of 1 μm to 200 μm (preferably 1 μm to 100 μm).

[0037] like Figure 4As shown, the positive electrode 32 includes a positive electrode current collector 32a, which is a conductive metal foil, and a positive electrode active material layer 32b applied to the surface of the positive electrode current collector 32a. A positive electrode tab 32t, exposing the positive electrode current collector 32a, is provided on one side X1 along the long side direction X of the positive electrode 32. Here, the positive electrode current collector 32a is generally rectangular. The positive electrode current collector 32a is made of conductive metals such as aluminum, aluminum alloy, nickel, or stainless steel. Here, the positive electrode current collector 32a is a metal foil, specifically an aluminum foil. Furthermore, the positive electrode active material layer 32b has a positive electrode active material capable of reversibly absorbing and releasing charge carriers. As the positive electrode active material, an oxide containing at least one of Ni, Co, and Mn is preferably used. Examples of positive electrode active materials include lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, lithium nickel manganese composite oxide, lithium nickel cobalt composite oxide, and other lithium transition metal composite oxides. The positive electrode active material is, for example, a composite oxide containing Ni and Li, and preferably a lithium-nickel composite oxide in which the Ni content in the composite oxide is in the range of 70 mol% to 100 mol% relative to the total molar percentage of the constituent elements other than Li and oxygen in the composite oxide. Alternatively, the positive electrode active material also includes active materials in which a portion of Ni, Co, and Mn is replaced by Al, Ti, Zr, P, B, Si, Nb, C, etc., or active materials whose particle surface is covered by compounds containing Al, Ti, Zr, W, P, B, Si, Nb, C, etc. The total amount of replacement and addition mentioned above is approximately 0.1 mol% to 7 mol%.

[0038] On the other hand, the negative electrode 34 is the electrode facing the positive electrode 32. The negative electrode 34 includes a negative electrode current collector 34a, which is a conductive metal foil, and a negative electrode active material layer 34b applied to the surface of the negative electrode current collector 34a. In addition, a negative electrode tab 34t exposed by the negative electrode current collector 34a is provided on the side edge of the negative electrode 34a on the other side X2 in the long side direction X. Here, the negative electrode current collector 34a is generally rectangular. The negative electrode current collector 34a is made of conductive metals such as copper, copper alloy, nickel, and stainless steel. Here, the negative electrode current collector 34a is a metal foil, specifically a copper foil. In addition, the negative electrode active material layer 34b is provided on the negative electrode current collector 34a. The negative electrode active material layer 34b has a negative electrode active material that can reversibly absorb and release charge carriers. Examples of negative electrode active materials include carbon materials such as graphite and carbon, and metals or compounds of metals such as Si, SiO, SiC, and Sn that can absorb lithium.

[0039] The separator 36 is an insulating sheet material located between the positive electrode 32 and the negative electrode 34. Here, the separator 36 is generally rectangular. For example, a porous resin sheet made of polyolefin resin such as polyethylene (PE) or polypropylene (PP) is preferably used as the separator 36. A heat resistance layer (HRL) containing inorganic fillers may also be provided on the surface of the separator 36. For example, alumina, boehmite, aluminum hydroxide, and titanium dioxide can be used as inorganic fillers.

[0040] The electrode body 30 in this embodiment is a stacked electrode body. Here, the electrode body 30 has a flat, generally rectangular shape. The electrode body 30 has a pair of generally rectangular wide surfaces. The electrode body 30 has a stacked structure consisting of multiple sheet-like positive electrodes 32 and sheet-like negative electrodes 34 separated by sheet-like separators 36. Figure 3 As shown, on both ends of the electrode body 30 along the long side direction X, there are a pair of end faces 30A and 30B, with the ends of a sheet-shaped positive electrode 32, a sheet-shaped negative electrode 34, and a sheet-shaped diaphragm 36 exposed to the outside. End faces 30A and 30B are the end faces (layered surfaces) of the laminated structure of the electrode body 30. End face 30A is arranged in the storage space 3 facing the sealing plate 20A. In addition, end face 30B is arranged in the storage space 3 facing the sealing plate 20B.

[0041] like Figure 6 As shown, end face 30A is arranged facing the liquid injection hole 22 of sealing plate 20A when electrode body 30 is housed in housing 70. In addition, end face 30A is arranged facing the partition wall portions 43a and 43b of spacer 40A, which will be described later.

[0042] There are no particular limitations on the size of the electrode body 30, as long as the effect of the technology disclosed herein is achieved. For example, in the case where the electrode body 30 has a pair of rectangular wide surfaces as in this embodiment, its length in the long side direction X is, for example, 10 cm or more, 15 cm or more, and from the viewpoint of being suitable for application to the technology disclosed herein, preferably 20 cm or more, more preferably 25 cm or more (for example, 28 cm or more). The upper limit of the length of the electrode body 30 in the long side direction X is, for example, 50 cm or less, and may also be 40 cm or less or 30 cm or less.

[0043] like Figure 3 As shown, the electrode body 30 is covered by an insulating film 80. The insulating film 80 can be cylindrical as in this embodiment, but in other embodiments it can be box-shaped or bag-shaped. Examples of materials constituting the insulating film 80 include polyolefin resins such as polyethylene (PE) and polypropylene (PP).

[0044] like Figure 3As shown, the electrolyte E is housed inside the casing 70. The type of electrolyte E can be the same as that of a typical secondary battery, without particular limitation. Electrolyte E is typically a non-aqueous liquid electrolyte (non-aqueous electrolyte) containing a non-aqueous solvent and a supporting salt. The non-aqueous solvent includes, for example, carbonates such as ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC). The non-aqueous solvent is preferably a solvent prepared by mixing EC, EMC, and DMC in a volume-based total ratio of 100%, ranging from 1% to 99%. The supporting salt is, for example, a fluorinated lithium salt. The fluorinated lithium salt preferably includes lithium hexafluorophosphate (LiPF6), lithium bis(fluorosulfonyl)imide (F2LiNO4S2) called LiFSI, or a lithium salt composed of these. The concentration of the supporting salt is preferably set to 0.6 mol to 1.8 mol per 1 L of non-aqueous solvent.

[0045] Here, the electrolyte E permeates the interior of the electrode body 30. Furthermore, as in this embodiment, a portion of the electrolyte E may exist as residual electrolyte on the exterior of the electrode body 30 (specifically, between the electrode body 30 and the housing 70). Alternatively, in other embodiments, the electrolyte E may not exist as residual electrolyte on the exterior of the electrode body 30. On the other hand, in the former case, it is easier to replenish the electrolyte E into the electrode body 30 when there is insufficient electrolyte E inside, which is therefore more preferable.

[0046] Regarding the amount of electrolyte E, please refer to the "Amount of Electrolyte" section in the manufacturing method of battery 1 described later. Although described later, in a preferred embodiment, the amount of electrolyte E is 200g or more. For example, large batteries with an electrolyte amount of 200g or more are suitable for application as the technology disclosed herein.

[0047] like Figure 3 As shown, spacer 40A is disposed within housing 70 between sealing plate 20A, which has injection hole 22 for injecting electrolyte E, and electrode body 30. Spacer 40B is disposed within housing 70 between sealing plate 20B and electrode body 30. In this embodiment, spacers 40A and 40B are disposed on both sides of electrode body 30 within housing 70. However, in other embodiments, spacer 40A may be disposed only in the space between sealing plate 20A, which has injection hole 22, and electrode body 30 within housing 70.

[0048] As the material constituting spacer 40A, insulating resins that can be used in general batteries can be used without particular limitation. Examples of materials constituting spacer 40A include polyolefin resins such as polyethylene (PE) and polypropylene (PP), polyamide resins, polyimide resins, polyacetal resins, and polyester resins. These can be one type alone or two or more types. Spacer 40A can be manufactured, for example, by stamping, forging, or casting. Furthermore, spacer 40B can also be manufactured using the same method.

[0049] The construction of spacer 40A will be described below. For example... Figure 5 and Figure 6 As shown, the spacer 40A has partition walls 43a and 43b that face the sealing plate 20A with the injection hole 22 and separate the housing space 3 of the housing 70 from the end space 4A on the side of the sealing plate 20A. The partition walls 43a and 43b each have multiple openings 43c1 and 43c2 that penetrate the partition walls 43a and 43b respectively. The multiple openings 43c1 exist in the partition wall 43a at a position offset from the area facing the injection hole 22.

[0050] like Figure 7 As shown, in this embodiment, the spacer 40A has first wall portions 41a, 41b and second wall portions 42a, 42b, 42c along the inner side of the housing 70. Additionally, as... Figure 5 As shown, a passage space 49 is formed in the middle of the spacer 40A to allow the conductive member A1 inside the positive electrode to pass through.

[0051] like Figure 7 As shown, the first wall portion 41a of the spacer 40A is a wall portion disposed along the inner side of the first side wall 14a of the housing 70. The first wall portion 41b of the spacer 40A is a wall portion disposed along the inner side of the first side wall 14c of the housing 70. The second wall portion 42a of the spacer 40A is a wall portion disposed along the inner side of the second side wall 14d of the housing 70. The second wall portions 42b and 42c of the spacer 40A are wall portions disposed along the inner side of the second side wall 14b of the housing 70. The second wall portion 42b of the spacer 40A is disposed near the side Z1 (the side of the first side wall 14a of the housing 70) in the height direction Z of the second side wall 14b of the housing 70. The second wall portion 42c of the spacer 40A is disposed near the other side Z2 (the side of the first side wall 14c of the housing 70) in the height direction Z of the second side wall 14b of the housing 70. Figure 5 As shown, the second wall portions 42b and 42c of the spacer 40A are interrupted in the region where the passage space 49 is formed.

[0052] like Figure 5As shown, spacer 40A has a first rib 44 that bridges the second wall portions 42a and 42c in the short-side direction Y. The first rib 44 is a flat plate extending from one side Y1 in the short-side direction Y towards the other side Y2. The partition wall portion 43a is separated by the first rib 44. In addition, spacer 40A has a second rib 46 and a third rib 47 extending in the short-side direction Y on both sides of the passage space 49. The second rib 46 and the third rib 47 are flat plate-shaped members. The second rib 46 is disposed between the second wall portions 42a and 42b of spacer 40A facing each other in the short-side direction Y. The third rib 47 is disposed between the second wall portions 42a and 42c of spacer 40A facing each other in the short-side direction Y.

[0053] like Figure 5 As shown, the spacer 40A has a liquid flow path 48 extending along the second wall portion 42a of the spacer 40A between the second rib 46 and the third rib 47. The liquid flow path 48 is a flat plate-shaped member protruding inward from the second wall portion 42a. The liquid flow path 48 bridges the partition walls 43a and 43b. The end 48a of the liquid flow path 48 on one side Z1 in the height direction Z is connected to the partition wall portion 43a. In addition, the end 48b of the liquid flow path 48 on the other side Z2 in the height direction Z is connected to the partition wall portion 43b.

[0054] Furthermore, as described above, the battery 1 of this embodiment includes a positive electrode internal conductive member A1 (positive electrode internal terminal 54 and electrode tab 30t) forming a conductive path from the electrode body 30 inside the casing 70 to the external terminal (positive electrode external terminal 52) outside the casing 70 (see reference). Figure 3 The spacer 40A has a passage space 49 through which the internal conductive member A1 of the positive electrode passes. Therefore, even when the spacer 40A is sandwiched between the sealing plate 20A and the electrode body 30, a conductive path from the electrode body 30 to the external terminal 52 of the positive electrode can be easily formed. Figure 6 As shown, a portion of the electrolyte E flows in downwards in the direction of gravity (the other side X2 of the long side direction X) through space 49.

[0055] like Figure 5 As shown, the partition walls 43a and 43b are supported by first walls 41a and 41b and second walls 42a, 42b, and 42c. The partition walls 43a and 43b are flat, generally rectangular plate-like members extending along the opposing directions (height direction Z) of the first sidewalls 14a and 14c, located between the electrode body 30 and the sealing plate 20A. The partition walls 43a and 43b separate the space from the end face 30A of the electrode body 30 by the space from which the electrolyte E is injected through the injection hole 22. Figure 6As shown, the partition walls 43a and 43b face the sealing plate 20A, separating the receiving space 3 and the end space 4A on the sealing plate 20A side. Furthermore, as described above, a passage space 49 is formed in the spacer 40A. Therefore, the partition walls 43a and 43b are separated in the region including the central portion in the height direction Z. Moreover, the partition walls 43a and 43b are bridged by a second wall 42a on the short side Y1 side and a liquid flow path 48.

[0056] like Figure 5 As shown, the spacer 40A has multiple openings 43c1 and 43c2 that penetrate the partition walls 43a and 43b. Figure 6 As shown, a portion of the electrolyte E injected into the casing 70 flows down through openings 43c1 and 43c2 in the direction of gravity (the other side of the long side X, X2).

[0057] Regarding the shape of openings 43c1 and 43c2 (the top view shape of openings 43c1 and 43c2), there are no particular limitations as long as the effects of the technology disclosed herein are achieved. The shape of openings 43c1 and 43c2 can be elliptical (oblong), as in this embodiment; in other embodiments, they can be various shapes such as circular, rectangular, and triangular. Furthermore, from the viewpoint of facilitating smoother flow of the electrolyte E, the shape of openings 43c1 and 43c2 is preferably a circle or ellipse without corners. Additionally, the shapes of the plurality of openings 43c1 and 43c2 can all be identical, as in this embodiment; in other embodiments, some or all of them can be different. For example, the shapes of the plurality of openings 43c1 and the plurality of openings 43c2 can also be different. Alternatively, for the plurality of openings 43c1, some or all of the openings can have different shapes. Similarly, for the plurality of openings 43c2, some or all of the openings can have different shapes. Furthermore, from the viewpoint of ease of manufacturing the spacer 40A, the shapes of the plurality of openings 43c1 and 43c2 are preferably all identical.

[0058] The number of openings 43c1 and 43c2 (hereinafter also simply referred to as "the number of openings") in the spacer 40A is not particularly limited as long as the effect of the technology disclosed herein is achieved. For example, the number of openings is 5 or more, and from the viewpoint of easily and uniformly supplying the electrolyte E to the electrode body 30, 10 or more is preferred, and 15 or more is more preferred. Furthermore, the upper limit of the number of openings is, for example, 30 or less, and from the viewpoint of appropriately ensuring the strength of the spacer 40A, 25 or less is preferred, and 20 or less is more preferred. In this embodiment, the number of openings is 16.

[0059] In spacer 40A, the ratio of the total area of ​​the plurality of openings 43c1, 43c2 to the area of ​​the liquid injection hole 22 (total area of ​​openings / area of ​​liquid injection hole) is 22 or more and 49 or less. For details, please refer to the explanation section on "ratio (total area of ​​openings / area of ​​liquid injection hole)" in the manufacturing method of battery 1 described later.

[0060] In spacer 40A, the cross-sectional area of ​​housing 70 along sealing plate 20A (equivalent to) Figure 11 When the slanted portion (the area of ​​the slanted portion) is set to 100%, the total area of ​​the multiple openings 43c1 and 43c2 accounts for more than 8%. For details, please refer to the corresponding explanatory section in the manufacturing method of battery 1 described later.

[0061] In spacer 40A, the area of ​​injection hole 22 when the cross-sectional area of ​​housing 70 along sealing plate 20A is set to 100% (equivalent to...) Figure 8 The proportion of the area (22A) is 0.2% or more. For details, please refer to the corresponding explanatory section in the manufacturing method of battery 1 described later.

[0062] The total area of ​​the plurality of openings 43c1 and 43c2 in the spacer 40A can be referred to the description of "total area of ​​openings" in the manufacturing method of battery 1 described later. In a preferred embodiment, the total area of ​​the plurality of openings 43c1 and 43c2 is 200 mm². 2 above.

[0063] For the area of ​​the liquid injection hole 22 in the sealing plate 20A, please refer to the description of "Area of ​​Liquid Injection Hole" in the manufacturing method of battery 1 described later. In a preferred embodiment, the area of ​​the liquid injection hole 22 in the sealing plate 20A is 6 mm². 2 above.

[0064] like Figure 7 As shown, multiple openings 43c1 and 43c2 exist in the partition walls 43a and 43b at positions offset from the region facing the injection hole 22. Here, "existing at positions offset from the region facing the injection hole" can include either a situation where the opening 43c1 is absent in the region facing the injection hole 22 in the partition wall 43a, or a situation where only a portion of the opening 43c1 exists in the region facing the injection hole 22. On the other hand, in the battery 1 manufacturing method described later, from the viewpoint of more reliably preventing the separator 36 from rolling up, the former is more preferable.

[0065] The spacer 40A has been described above. Furthermore, as mentioned above, in the battery 1 of this embodiment, a spacer 40B is also disposed on the other side X2 in the longitudinal direction X. Figure 3As shown, spacer 40B faces sealing plate 20B, separating the storage space 3 of housing 70 and the end space 4B on the sealing plate 20B side. Spacer 40B has a structure substantially the same as spacer 40A, therefore a detailed description of its structure is omitted. Furthermore, in this embodiment, spacers 40A and 40B have the same structure, but in other embodiments, they may be different.

[0066] <Battery Manufacturing Method>

[0067] The manufacturing method of battery 1 according to this embodiment will be described below. Figure 9 This is a flowchart illustrating a method for manufacturing battery 1 according to one embodiment. Figure 10 , Figure 12 as well as Figure 13 These are a first schematic diagram, a second schematic diagram, and a third schematic diagram used to illustrate the liquid injection process S2 of one embodiment. Figure 11 It is a schematic representation along Figure 10 A schematic diagram of the cross-section of line A-A. Furthermore, the following description of the manufacturing method is not intended to limit the manufacturing method of this disclosure to the following method. Additionally, the steps described below can be performed in a suitable order. Moreover, in addition to the steps described below, other processes may be added as needed.

[0068] like Figure 9 As shown, the manufacturing method of battery 1 in this embodiment includes: a preparation step S1 for preparing battery assembly 2; and an electrolyte injection step S2 for injecting electrolyte E into battery assembly 2. Additionally, as... Figure 10 , Figure 12 as well as Figure 13 As shown, in the electrolyte injection process S2, the battery assembly 2 is placed with the sealing plate 20A, which has the injection hole 22, facing upwards (towards the side X1 in the long side direction X), and the electrolyte E is injected (injected) through the injection port 120A inserted into the injection hole 22. Furthermore, in this specification, "opening" can refer to a through hole in the partition wall that can serve as a flow path for the electrolyte. That is, openings in the partition wall that are provided for other purposes (e.g., openings for passing through electrode tabs, openings for passing through electrode terminals, etc.) are not included in "opening". The following describes each process.

[0069] <Preparation Process S1>

[0070] As described above, in this process, battery assembly 2 is prepared. Figure 10 As shown, the battery assembly 2 includes a housing 70, an electrode body 30 housed in the housing 70, and spacers 40A and 40B. The preparation step S1 of this embodiment will be described below.

[0071] The battery assembly 2 can be constructed, for example, by the following method. First, the electrode body 30, the housing 70, and the spacers 40A and 40B are assembled. Specifically, the plurality of positive electrode tabs 32t of the electrode body 30 are joined to the positive internal terminal 54. Additionally, the plurality of negative electrode tabs 34t are joined to the negative internal terminal 64. Then, the spacers 40A and 40B are installed on the electrode body 30, and their surroundings are covered with an insulating film 80. Next, the negative external terminal 62, fixed to the sealing plate 20B, is joined to the negative internal terminal 64. This integrated assembly is inserted from one opening 12b of the housing body 10. Next, the positive external terminal 52, fixed to the sealing plate 20A, is joined to the positive internal terminal 54. Then, the sealing plates 20A and 20B are welded to the openings 12a and 12b of the housing body 10, respectively. At this time, the end face 30A of the stacked structure of the electrode body 30 is arranged facing the sealing plate 20A. In addition, in this embodiment, the sealing plate 20B is also arranged facing the end face 30B of the laminated structure. This allows the battery assembly 2 to be assembled.

[0072] In the disclosed technology, the ratio of the total area of ​​the plurality of openings 43c1, 43c2 of the prepared spacer 40A to the area of ​​the injection hole 22 (total area of ​​openings / area of ​​injection hole) is 22 or more and 49 or less. For example, the ratio (total area of ​​openings / area of ​​injection hole) can be 25 or more, 30 or more, or 40 or more. Alternatively, the ratio (total area of ​​openings / area of ​​injection hole) can be 45 or less.

[0073] Furthermore, in this embodiment, the "total area of ​​the openings" refers to the total area of ​​the 12 openings 43c1 disposed in the partition wall portion 43a and the 4 openings 43c2 disposed in the partition wall portion 43b, totaling 16 openings 43c. The area of ​​each of the openings 43c1 and 43c2 corresponds to... Figure 7 The slanted portion (43d). The "area of ​​the opening" can also be referred to as the void area of ​​the opening. Alternatively, the "area of ​​the opening" can also be referred to as the top-view area of ​​the opening. Furthermore, in this embodiment, the "area of ​​the injection hole" refers to the top-view area of ​​the injection hole 22. As described above, the area of ​​the injection hole 22 corresponds to... Figure 8 The slanted portion (22A). The area of ​​injection hole 22 can also be referred to as the area of ​​the portion of injection hole 22 into which electrolyte E flows.

[0074] In the disclosed technology, the ratio of the total area of ​​the plurality of openings 43c1, 43c2 of the spacer 40A prepared above, when the cross-sectional area of ​​the housing 70 along the sealing plate 20A is set to 100% (hereinafter also simply referred to as the "area ratio of the openings of the spacer") is 8% or more. From the viewpoint of more appropriately shortening the electrolyte E injection time, the opening ratio of the spacer 40A is preferably 10% or more, more preferably 15% or more. In addition, the upper limit of the opening ratio of the spacer 40A is, for example, 20% or less, and may also be 16% or less.

[0075] The "area ratio of the openings in the spacer" can be calculated by multiplying (total area of ​​openings / area of ​​the cross-section along the sidewall) by 100%. For example, in this embodiment, "area of ​​the cross-section along the sidewall" refers to the area of ​​the housing 70 along the sealing plate 20A having the injection hole 22. Specifically, it refers to... Figure 10 The area of ​​section A-A ( Figure 11 (The area of ​​the slanted portion). Furthermore, the cross-sectional area of ​​the housing 70, the total area of ​​the multiple openings 43c1 and 43c2, and the area of ​​the injection hole 22 can be measured, for example, using a CNC (Computerized Numerical Control) image measuring machine. As a CNC image measuring machine, commercially available devices can be used without particular limitations.

[0076] In the disclosed technology, the area ratio (hereinafter also simply referred to as "the area ratio of the injection hole") of the spacer 40A prepared above, when the cross-sectional area of ​​the housing 70 along the sealing plate 20A is set to 100%, is 0.2% or more. From the viewpoint of more appropriately shortening the injection time of the electrolyte E, the area ratio of the injection hole 22 is preferably 0.3% or more, more preferably 0.4% or more. In addition, the upper limit of the area ratio of the injection hole 22 is, for example, 0.6% or less, and may also be 0.5% or less.

[0077] Although not specifically limited, the average area of ​​multiple openings 43c1, 43c2 is, for example, 10 mm². 2 The above can also be 15mm. 2 That's all. On the other hand, in the injection process S2 described later, from the viewpoint of more appropriately balancing the reduction of injection time and the prevention of diaphragm 36 roll-up, the average area of ​​the plurality of openings 43c1, 43c2 is preferably 20 mm. 2 Above, 23mm 2 That's all. Additionally, the upper limit of the average area of ​​the multiple openings 43c1 and 43c2 is, for example, 50 mm². 2 Below. On the other hand, from the viewpoint of more appropriately obtaining the effects described above, 40mm is preferred. 2Below, 30mm 2 the following.

[0078] Furthermore, in this specification, "average area of ​​the openings" can refer to the value obtained by dividing the total area of ​​the openings by the number of openings. More specifically, it can be calculated as (total area of ​​openings / number of openings). As described above, for example, in this embodiment, "total area of ​​the openings" refers to the total area of ​​the 12 openings 43c1 disposed in the partition wall portion 43a and the 4 openings 43c2 disposed in the partition wall portion 43b, which is a total of 16 openings 43c1, 43c2. Additionally, as described above, "number of openings" is 16.

[0079] Although not specifically limited, the total area of ​​multiple openings 43c1 and 43c2 is, for example, 190 mm². 2 That's all. On the other hand, in the injection process S2 described later, from the viewpoint of more appropriately shortening the injection time, 200 mm is preferred. 2 Above, 230mm 2 The above is preferred, with 280mm being even better. 2 The above is further preferred to be 400mm. 2 Above (e.g., 420mm) 2 (Above). Additionally, the maximum total area of ​​the multiple openings 43c1 and 43c2 is, for example, 500 mm². 2 The following can also be 450mm 2 Below, 430mm 2 the following.

[0080] Although not specifically limited, in the sealing plate 20A, the area of ​​the injection hole 22 is, for example, 5 mm². 2 That's all. On the other hand, from the viewpoint of more appropriately shortening the injection time, the area of ​​the injection hole 22 is preferably 6 mm. 2 The above is preferred to be 8mm. 2 The above is particularly preferred to be 12mm. 2 That's all. Additionally, the upper limit of the area of ​​the injection hole 22 is, for example, 20 mm. 2 The following can also be 15mm. 2 Below, 13mm 2 the following.

[0081] <Injection Process S2>

[0082] As described above, in this process, electrolyte E is injected into battery assembly 2. Hereinafter, the electrolyte injection process S2 of this embodiment will be described.

[0083] First, such as Figure 10As shown, the battery assembly 2 is mounted with the sealing plate 20A, which has the injection hole 22, facing upwards (here, on the side X1 in the long side direction X). Then, in this embodiment, as... Figure 12 As shown, electrolyte E is injected through injection hole 22 using hopper 100. More specifically, electrolyte E is injected through injection port 120A of hopper 100 inserted into injection hole 22. While injection using hopper 100 can shorten the injection time compared to conventional nozzle injection, there is a tendency for a larger volume of electrolyte E injected per unit time. Consequently, issues such as diaphragm 36 of electrode body 30 rolling up arise. In contrast, according to the technology disclosed herein, even when injecting electrolyte E using hopper 100, diaphragm 36 rolling up can be appropriately prevented.

[0084] Here, the hopper 100 is a component that injects electrolyte E into the battery 1 through the injection hole 22. There are no particular limitations on the shape of the hopper 100, as long as the effects of the disclosed technology are achieved. In this embodiment, as... Figure 12 As shown, a funnel-shaped hopper 100 is used. The hopper 100 includes an electrolyte receiving section 110 and an injection section 120. The injection section 120 has an injection port 120A. Here, the electrolyte receiving section 110 is the part that receives the electrolyte E. The injection section 120 is the part that injects the electrolyte E received in the electrolyte receiving section 110 into the battery 1 through the injection hole 22. The injection section 120 can be a thin tube as in this embodiment, and can also be a needle in other embodiments. The size of the electrolyte receiving section 110 and the injection section 120 is preferably appropriately determined according to the amount of electrolyte E to be injected. In addition, in this embodiment, the injection section 120 includes a stopcock (not shown) that can adjust the opening / closing of the injection of electrolyte E. The hopper 100 can be made of metal, resin, or a combination thereof. As the hopper 100, commercially available hoppers can be used without particular limitations.

[0085] Next, the injection method of this embodiment will be described. Specifically, firstly, as Figure 10 As shown, the pressure of battery 1 is reduced (refer to white arrow S). There are no particular limitations on the conditions for pressure reduction, as long as the effects of the disclosed technology are achieved. The pressure during pressure reduction can be set, for example, in the range of -50 kPa to -100 kPa (preferably -70 kPa to -100 kPa). Furthermore, the pressure reduction time can be set, for example, in the range of 10 seconds to 60 seconds (preferably 20 seconds to 40 seconds). Next, as... Figure 12As shown, the filling port 120A of the filling section 120 of the hopper 100 is inserted into the filling hole 22 of the battery 1. Then, a predetermined amount of electrolyte E is loaded into the electrolyte receiving section 110. Next, pressure is applied while opening the stopcock of the filling section 120 (not shown) (refer to the white arrow T). Although not limited to this, the pressure applied can be set to, for example, within the range of 0.2 MPa to 5 MPa (preferably 0.5 MPa to 2 MPa). In this way, electrolyte E can be injected into the battery 1 (refer to...). Figure 12 White arrow U, Figure 13 The white arrow V).

[0086] In a preferred embodiment, such as this one, multiple openings 43c1 exist in the partition wall portion 43a at positions offset from the region facing the injection hole 22. According to this structure, direct impact of the electrolyte E on the end face 30A of the laminated structure of the electrode body 30 can be more appropriately prevented. Therefore, rollover of the diaphragm 36 can be more appropriately prevented.

[0087] The amount of electrolyte E injected is, for example, 100g or more, or 150g or more. On the other hand, in a preferred embodiment, the amount of electrolyte E injected is 200g or more, more preferably 250g or more, or 280g or more. According to the manufacturing method of battery 1, the rollover of the separator 36 can be appropriately prevented. Therefore, large batteries, for example, with a relatively large amount of electrolyte E as described above, tend to have a longer injection time, and are therefore suitable for application. Although not particularly limited, the upper limit of the amount of electrolyte E injected is, for example, 500g or less, or even 400g or less, or 300g or less. Furthermore, although not particularly limited, the viscosity of the electrolyte E injected can be, for example, set to 0.1mPa·s to 1mPa·s (preferably 0.1mPa·s to 0.5mPa·s) at 25°C. This viscosity can be measured, for example, using a commercially available rotational viscometer. Moreover, as the water and solvent mentioned above, commercially available water and solvents can be used without particular restriction.

[0088] While not limited to this, the electrolyte E injection rate is, for example, 10 g / s or more, and from the viewpoint of appropriately shortening the injection time, preferably 20 g / s or more, 30 g / s or more, and more preferably 40 g / s or more, 50 g / s or more. Furthermore, the upper limit of the electrolyte E injection rate is, for example, 70 g / s or less, and from the viewpoint of appropriately preventing the separator 36 from rolling up, preferably 60 g / s or less. Moreover, although not particularly limited, in one embodiment, from the viewpoint of more appropriately improving the productivity of the battery 1, the electrolyte E injection time is, for example, preferably 12 seconds or less, more preferably 10 seconds or less, and even more preferably 9 seconds or less, 8 seconds or less, or 5 seconds or less.

[0089] After the liquid injection process S2 is completed, the liquid injection hole 22 is sealed by the liquid injection plug 24. Then, appropriate initial charging, aging and other treatments are performed to obtain battery 1.

[0090] Battery 1 can be used for various purposes, such as preferably as a power source (drive power source) for motors in vehicles such as passenger cars and trucks. There is no particular limitation on the type of vehicle, but examples include plug-in hybrid electric vehicles (PHEVs), hybrid electric vehicles (HEVs), and battery electric vehicles (BEVs).

[0091] From the perspective of improving the productivity of battery 1, it is necessary to develop a technology that can simultaneously prevent the sheet-like separator 36 from rolling up and shorten the electrolyte E injection time during the manufacturing of battery 1. According to the battery 1 manufacturing method described above, in the electrolyte injection step S2, with a spacer 40A positioned between the sealing plate 20A and the electrode body 30, electrolyte E is injected through the injection hole 22. Furthermore, in the battery 1 manufacturing method described above, the ratio of (total area of ​​openings / area of ​​injection hole), the area ratio of the spacer openings, and the area ratio of the injection hole are set to an appropriate range. This allows for the simultaneous prevention of the sheet-like separator 36 rolling up and the shortening of the electrolyte E injection time. Additionally, in the battery 1 obtained by the above manufacturing method, the rolling up of the separator 36 can be appropriately prevented. Therefore, battery 1 can be considered a high-quality battery.

[0092] Furthermore, the spacer 40A in the structure described above serves the following effect. First, as... Figure 6 As shown, electrolyte E injected through injection hole 22 flows into partition wall portion 43a. At this time, a portion of electrolyte E flows in from opening 43c1 of partition wall portion 43a. This allows electrolyte E to be supplied to the end of side Z2 in the height direction Z. Additionally, a portion of electrolyte E diffused in partition wall portion 43a flows in from passage space 49 through which the internal conductive member A of the positive electrode passes. This allows electrolyte E to be supplied to the central portion in the height direction Z. Then, the remaining electrolyte E reaches partition wall portion 43b along liquid flow path 48 and flows in from opening 43c2 of partition wall portion 43b. This allows electrolyte E to be supplied to the end of the other side Z1 in the height direction Z. As described above, the first spacer 40A has liquid flow path 48, therefore, electrolyte E can be injected more efficiently throughout the entire region in the height direction Z.

[0093] As described above, spacer 40A includes first wall portions 41a, 41b and second wall portions 42a, 42b, 42c. Therefore, even when an impact is applied to the battery 1 in the long side direction X, deformation of spacer 40A can be appropriately prevented. In spacer 40A, the first rib 44, the second rib 46, and the third rib 47 further restrict deformation of the second wall portions 42a, 42c inward in the short side direction Y. The same applies to spacer 40B. Furthermore, spacers 40A and 40B prevent communication between the electrode body 30 and the sealing plates 20A and 20B. Moreover, spacers 40A and 40B restrict movement of the electrode body 30 in the long side direction X. Therefore, damage to the electrode body 30 (e.g., electrode tab 30t) can be prevented.

[0094] [Experimental Example]

[0095] The following describes test examples related to the technology disclosed herein. Furthermore, the content of the test examples described below is not intended to limit the technology disclosed herein.

[0096] 1. Fabrication of the experimental battery

[0097] In this experiment, nine test batteries with different total area of ​​openings and different areas of injection holes were fabricated. The injection time was measured and the presence or absence of diaphragm roll-up was confirmed. The fabrication of each test battery is described below.

[0098] (Examples 1 to 8)

[0099] As an experimental battery, it was made as follows Figure 3 The battery shown is constructed by first stacking multiple sheet-shaped positive and negative electrodes separated by a sheet-shaped separator to form a laminated electrode body (length 284 mm in the long side × length 88 mm in the height side × length 13 mm in the short side). Here, lithium nickel cobalt manganese composite oxide (LiNi) is used as the positive electrode active material. 1／3 Co 1／3 Mn 1／3O2). Aluminum foil was used as the positive current collector. Graphite was used as the negative active material. Copper foil was used as the negative current collector. Furthermore, a three-layer PP / PE / PE separator was used. Then, two stacked electrode bodies manufactured as described above were inserted into a cylindrical housing body (aluminum, 308mm long side × 90mm height × 30mm short side) with spacers. In Examples 1-8, spacers with the ratio of total opening area to spacer opening area shown in Table 1 were used. Additionally, in Examples 1-8, sealing plates with injection holes having the areas shown in Table 1 were used. Furthermore, the total area of ​​the spacer openings varied by increasing or decreasing the number of openings in the spacers. The average area of ​​the spacer openings was set to 23.7 mm². 2 Then, use a sealing plate to seal the openings on both sides of the main body of the casing.

[0100] (Example 9)

[0101] The test battery of Example 7 was manufactured in the same manner as Examples 1-6 and 8-10, except that two stacked electrodes were inserted into the housing body without spacers.

[0102] 2. Determination of injection time

[0103] First, such as Figure 10 As shown, the internal pressure of each test battery was reduced to below -96 kPa for 30 seconds. Then, as... Figure 12 As shown, a hopper is installed at the injection port, and the entire amount of electrolyte is loaded into the electrolyte receiving section of the hopper. Here, in Examples 1-9, 289g of electrolyte is loaded into the electrolyte receiving section respectively. Then, as... Figure 13 As shown, the electrolyte filling section was opened, and the electrolyte storage section was pressurized at 0.8 MPa while electrolyte was injected into each test battery. The time from the start of electrolyte injection until the electrolyte in the electrolyte storage section disappeared was measured as the filling time. The "Injection Time" column in Table 1 shows the results. Here, if the "Injection Time" is 12 seconds or less (preferably 10 seconds or less), it is considered that the time can be shortened. In addition, as the electrolyte, a mixed solvent (non-aqueous electrolyte) containing ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC) in a volume ratio of 3:4:3 was prepared. In addition, a solution containing LiPF6 as a supporting salt at a concentration of 1.0 mol / L was used.

[0104] 3. Confirmation of the presence or absence of diaphragm roll-up

[0105] First, disassemble each test cell after liquid injection. Then, remove the electrode from each test cell and visually confirm whether the separator of the electrode is rolled up. The "Presence or absence of separator rolling up" column in Table 1 indicates the results. "×" indicates that separator rolling up was confirmed in the electrode, and "〇" indicates that separator rolling up was not confirmed in the electrode.

[0106] Table 1

[0107]

[0108] As shown in Table 1, in Examples 1 to 5 where the ratio (total area of ​​spacer openings / area of ​​injection hole) is 22 or more and 49 or less, the area ratio of injection hole is 0.2% or more, and the area ratio of spacer openings is 8% or more, it was confirmed that the injection time can be shortened and diaphragm rollover can be appropriately prevented. On the other hand, in Examples 6 to 8 where the ratio (total area of ​​spacer openings / area of ​​injection hole) is outside the above range, and in Example 9 where there is no spacer, it was confirmed that it is impossible to simultaneously shorten the injection time and prevent diaphragm rollover.

[0109] Furthermore, based on Examples 1 to 5, it was confirmed that, under the condition that the above conditions are met, the total area of ​​the openings of the spacer is preferably 200 mm². 2 Above (e.g., 230mm) 2 (Above). Furthermore, based on Examples 1 to 5, it was confirmed that, under the condition that the above conditions are met, the area of ​​the injection hole is preferably 6 mm. 2 above.

[0110] Furthermore, it was confirmed that even when using a hopper to inject electrolyte, diaphragm rollover can be appropriately prevented. By using a hopper, the injection time can be appropriately shortened compared to conventional nozzle-type methods.

[0111] The embodiments of the technology disclosed herein have been described above. However, the above description is merely illustrative and does not limit the scope of the claims. The technology described in the claims includes technologies obtained by various modifications and alterations to the specific examples illustrated in the above description.

[0112] For example, in the above-mentioned test case, a large battery was used for the test, but the technology disclosed herein can of course also be applied to batteries other than large batteries.

[0113] For example, in the above embodiment, the electrode body 30 is a stacked electrode body, but it is not limited to this. In other embodiments, the electrode body 30 may also be a wound electrode body formed by winding multiple stacked sheets of positive electrode 32 and negative electrode 34 separated by sheet-like separators 36. In addition, the number of electrode bodies 30 provided in the battery 1 may be two as in this embodiment, but in other embodiments, it may be one or more. Moreover, in other embodiments, the electrode body 30 may not have positive electrode tabs 32t and negative electrode tabs 34t.

[0114] For example, in the above embodiment, the shape of the housing 70 is set to approximately cuboid, but unless otherwise specified, the shape of the housing 70 is not limited. For example, the shape of the housing 70 can also be various shapes such as a cylinder. In addition, when the shape of the housing 70 is cylindrical, the electrode body 30 can also be a cylindrical wound electrode body housed inside the housing 70. Furthermore, the spacers 20A and 20B can also be circular plate-shaped components disposed within the cylindrical housing 70 between the side wall of the housing 70 and the electrode body 30.

[0115] For example, in the above embodiment, a liquid injection hole 22 is present in the sealing plate 20A having the positive terminal 50, but this is not a limitation. In other embodiments, a liquid injection hole 22 may also be present in the sealing plate 20B having the negative terminal 60.

[0116] For example, in the above embodiment, sealing plates 20A and 20B respectively have a positive terminal 50 and a negative terminal 60, but are not limited thereto. In other embodiments, both the positive terminal 50 and the negative terminal 60 may be disposed on one of the sealing plates 20A and 20B. In this case, for example, a liquid injection hole 22 can be provided on the sealing plate having the positive terminal 50 and the negative terminal 60. Alternatively, in other embodiments, the battery may also include: an outer casing 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 that seals the opening of the outer casing. In this case, for example, electrode terminals and a liquid injection hole can be disposed on the sealing plate.

[0117] For example, in the above embodiment, the spacer 40A has first wall portions 41a, 41b, second wall portions 42a, 42b, 43c and partition wall portions 43a, 43b, but the shape of the spacer is not limited to this.

[0118] For example, in the above embodiment, an electrolyte E is injected through the injection port 22 using a hopper, but this is not a limitation. In other embodiments, a nozzle can be used for injection. On the other hand, from the viewpoint of appropriately shortening the injection time, it is more preferable to use a hopper capable of injecting a large amount of electrolyte E at once.

[0119] As described above, the following are examples of specific methods that can be used as specific embodiments of the technology disclosed herein.

[0120] Item 1: A method for manufacturing an energy storage device, wherein the method for manufacturing the energy storage device includes:

[0121] Preparation procedures for energy storage equipment components; and

[0122] The electrolyte injection process for injecting electrolyte into the energy storage device components.

[0123] Here,

[0124] The energy storage device component includes:

[0125] case;

[0126] The electrode body housed in the housing; and

[0127] Spacer

[0128] The housing has a storage space for accommodating the electrode body and a sidewall with an injection hole for injecting the electrolyte.

[0129] The electrode body has a laminated structure consisting of sheet-like positive electrodes and sheet-like negative electrodes separated by sheet-like membranes.

[0130] The end faces of the stacked structure are arranged in the storage space facing the sidewalls.

[0131] The spacer is disposed within the housing between the side wall and the electrode body.

[0132] It has a partition wall portion facing the sidewall and separating the storage space from the end space on the sidewall side.

[0133] The partition wall has multiple openings that penetrate the partition wall.

[0134] The ratio of the total area of ​​the plurality of openings to the area of ​​the injection hole (total area of ​​openings / area of ​​injection hole) is 22 or more and 49 or less.

[0135] When the cross-sectional area of ​​the housing along the sidewall is set to 100%, the total area of ​​the plurality of openings is 8% or more.

[0136] The proportion of the area of ​​the injection hole when the cross-sectional area of ​​the housing along the side wall is set to 100% is 0.2% or more.

[0137] In the liquid injection process,

[0138] The energy storage device assembly is mounted with the sidewall having the injection hole facing upwards, and the electrolyte is injected through the injection port inserted into the injection hole.

[0139] Item 2:

[0140] In the method for manufacturing the energy storage device according to item 1, the electrolyte is injected using a hopper in the electrolyte injection step.

[0141] Item 3:

[0142] In the method for manufacturing the energy storage device described in item 1 or 2, the amount of electrolyte is 200g or more.

[0143] Item 4:

[0144] In the method of manufacturing the energy storage device according to any one of items 1 to 3, the total area of ​​the plurality of openings in the spacer is 200 mm². 2 above.

[0145] Item 5:

[0146] In the method of manufacturing the energy storage device according to any one of items 1 to 4, the area of ​​the liquid injection hole in the side wall is 6 mm. 2 above.

[0147] Item 6:

[0148] In the method of manufacturing an energy storage device according to any one of items 1 to 5, the plurality of openings exist in the partition wall portion at a position offset from the region opposite to the injection hole.

[0149] Item 7: An energy storage device, wherein the energy storage device comprises:

[0150] Electrode body;

[0151] Electrolyte;

[0152] A housing that houses the electrode body and the electrolyte; and

[0153] Spacer

[0154] The housing has a storage space for accommodating the electrode body and a sidewall with an injection hole for injecting the electrolyte.

[0155] The electrode body has a laminated structure consisting of sheet-like positive electrodes and sheet-like negative electrodes separated by sheet-like membranes.

[0156] The end faces of the stacked structure are arranged in the storage space facing the sidewalls.

[0157] The spacer is disposed within the housing between the side wall and the electrode body.

[0158] It has a partition wall portion facing the sidewall and separating the storage space from the end space on the sidewall side.

[0159] The partition wall has multiple openings that penetrate the partition wall.

[0160] The ratio of the total area of ​​the plurality of openings to the area of ​​the injection hole (total area of ​​openings / area of ​​injection hole) is 22 or more and 49 or less.

[0161] When the cross-sectional area of ​​the housing along the sidewall is set to 100%, the total area of ​​the plurality of openings is 8% or more.

[0162] The proportion of the area of ​​the injection hole when the cross-sectional area of ​​the housing along the side wall is set to 100% is 0.2% or more.

[0163] Item 8:

[0164] In the energy storage device described in item 7, the amount of electrolyte is 200g or more.

[0165] Item 9:

[0166] In the energy storage device described in item 7 or 8, the total area of ​​the plurality of openings in the spacer is 200 mm². 2 above.

[0167] Item 10:

[0168] In any one of items 7 to 9, the area of ​​the liquid injection hole in the side wall is 6 mm². 2 above.

[0169] Item 11:

[0170] In any one of items 7 to 10, the plurality of openings are located in the partition wall portion at a position offset from the region opposite to the injection hole.

[0171] Explanation of reference numerals in the attached figures

[0172] 1 Battery

[0173] 2 Battery Components

[0174] 3. Storage space

[0175] 4A, 4B end spaces

[0176] 10. Shell Body

[0177] 12a, 12b openings

[0178] 14a, 14c First sidewall

[0179] 14b, 14d Second lateral wall

[0180] 20A and 20B sealing boards

[0181] 21 Insulating components

[0182] 22 Injection Holes

[0183] 24 Sealing plugs

[0184] 30 Electrode Body

[0185] 40A and 40B spacers

[0186] 41a, 41b First wall section

[0187] 42a, 42b, 42c Second wall section

[0188] 43a, 43b Separation wall section

[0189] 43c1, 43c2 opening

[0190] 44 First Rib

[0191] 46 Second Rib

[0192] 47 Third Rib

[0193] 48 Liquid flow path

[0194] 49 Through Space

[0195] 50 positive extremes

[0196] 60 Negative extremes

[0197] 70 Housing

[0198] 80 Insulating film

[0199] 100 hoppers

[0200] 110 Electrolyte Storage Section

[0201] 120 Liquid injection part.

Claims

1. A method for manufacturing an energy storage device, wherein, The method for manufacturing the energy storage device includes: Preparation procedures for energy storage equipment components; and The electrolyte injection process for injecting electrolyte into the energy storage device components. Here, The energy storage device component includes: case; The electrode body housed in the housing; and Spacer The housing has a storage space for accommodating the electrode body and a sidewall with an injection hole for injecting the electrolyte. The electrode body has a laminated structure consisting of sheet-like positive electrodes and sheet-like negative electrodes separated by sheet-like membranes. The end faces of the stacked structure are arranged in the storage space facing the sidewalls. The spacer is disposed within the housing between the side wall and the electrode body. It has a partition wall portion facing the sidewall and separating the storage space from the end space on the sidewall side. The partition wall has multiple openings that penetrate the partition wall. The ratio of the total area of ​​the plurality of openings to the area of ​​the injection hole, i.e., the total area of ​​the openings / the area of ​​the injection hole, is 22 or more and 49 or less. When the cross-sectional area of ​​the housing along the sidewall is set to 100%, the total area of ​​the plurality of openings is 8% or more. The proportion of the area of ​​the injection hole when the cross-sectional area of ​​the housing along the side wall is set to 100% is 0.2% or more. In the liquid injection process, The energy storage device assembly is mounted with the sidewall having the injection hole facing upwards, and the electrolyte is injected through the injection port inserted into the injection hole.

2. The method for manufacturing the energy storage device according to claim 1, wherein, In the electrolyte injection process, the electrolyte is injected using a hopper.

3. The method for manufacturing the energy storage device according to claim 1 or 2, wherein, The amount of electrolyte is 200g or more.

4. The method for manufacturing the energy storage device according to claim 1 or 2, wherein, In the spacer, the total area of ​​the plurality of openings is 200 mm². 2 above.

5. The method for manufacturing the energy storage device according to claim 1 or 2, wherein, The area of ​​the injection hole in the sidewall is 6 mm. 2 above.

6. The method for manufacturing the energy storage device according to claim 1 or 2, wherein, The plurality of openings exist in the partition wall at positions offset from the region opposite to the injection hole.

7. An energy storage device, wherein, The energy storage device includes: Electrode body; Electrolyte; A housing for accommodating the electrode body and the electrolyte; as well as Spacer The housing has a storage space for accommodating the electrode body and a sidewall with an injection hole for injecting the electrolyte. The electrode body has a laminated structure consisting of sheet-like positive electrodes and sheet-like negative electrodes separated by sheet-like membranes. The end faces of the stacked structure are arranged in the storage space facing the sidewalls. The spacer is disposed within the housing between the side wall and the electrode body. It has a partition wall portion facing the sidewall and separating the storage space from the end space on the sidewall side. The partition wall has multiple openings that penetrate the partition wall. The ratio of the total area of ​​the plurality of openings to the area of ​​the injection hole, i.e., the total area of ​​the openings / the area of ​​the injection hole, is 22 or more and 49 or less. When the cross-sectional area of ​​the housing along the sidewall is set to 100%, the total area of ​​the plurality of openings is 8% or more. The proportion of the area of ​​the injection hole when the cross-sectional area of ​​the housing along the side wall is set to 100% is 0.2% or more.

8. The energy storage device according to claim 7, wherein, The amount of electrolyte is 200g or more.

9. The energy storage device according to claim 7 or 8, wherein, In the spacer, the total area of ​​the plurality of openings is 200 mm². 2 above.

10. The energy storage device according to claim 7 or 8, wherein, The area of ​​the injection hole in the sidewall is 6 mm. 2 above.

11. The energy storage device according to claim 7 or 8, wherein, The plurality of openings exist in the partition wall at positions offset from the region opposite to the injection hole.

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