Method for manufacturing an electrical storage device

Abstract

The present disclosure aims to provide a manufacturing method of an electrical storage device, which suppresses expansion of a case due to gas generated along with charge and discharge of the electrical storage device, and suppresses deterioration of the operation accuracy of an exhaust valve due to pressing of the case. In a sealing process involved in the manufacturing method of the present disclosure, a first pressing jig presses a third face in a first face direction at a first load value, and a second pressing jig presses a pair of second faces from both sides at a second load value, and a liquid injection hole is sealed in a state where the second faces are deformed toward the inner surface direction of the case main body. In a case arrangement process, the case is arranged on a holding member in such a manner that the base portion of the holding member is in contact with the first face (12a) of the case main body. In the sealing process, the region where the first pressing jig opposes the third face is composed of a material having a lower hardness than the holding member, and the second load value is greater than the first load value.

Description

Technical Field

[0001] This disclosure relates to a method for manufacturing an energy storage device. Background Technology

[0002] Energy storage devices such as lithium-ion secondary batteries include, for example, an electrode body, an electrolyte, and a housing that contains the electrode body and the electrolyte. The housing includes a sealing plate and a housing body. For example, Japanese Patent Publication No. 2024-64657 discloses a method for manufacturing a secondary battery that can suppress the convex expansion of the battery housing caused by gas generated during the charging and discharging of the secondary battery (energy storage device), and can also suppress the increase in the height of the battery housing when it is pressed.

[0003] Patent Document 1: Japanese Patent Publication No. 2024-64657

[0004] However, sometimes an exhaust valve is installed on the housing of such energy storage devices to release gas from the housing to the outside when the pressure inside the housing reaches a specified value. When the housing of this structure is pressed, the surface of the housing where the exhaust valve is located deforms, which may cause the exhaust valve to malfunction. Therefore, there is still room for further improvement in the above technology. Summary of the Invention

[0005] This disclosure was made in view of the above circumstances, and its main objective is to provide a method for manufacturing an energy storage device that can suppress the expansion of the housing caused by gas generated during the charging and discharging of the energy storage device, and can suppress the deterioration of the operating accuracy of the exhaust valve caused by pressing the housing.

[0006] The technology disclosed herein relates to a method for manufacturing an energy storage device, which includes an electrode body comprising a positive electrode and a negative electrode, an electrolyte, and a housing containing the electrode body and the electrolyte. The housing comprises: a housing body having a generally rectangular first surface having a pair of long sides and a pair of short sides; a pair of second surfaces extending from the pair of long sides and having an area larger than the first surface; a third surface facing the first surface; and one or more openings; and one or more sealing plates sealing the one or more openings. The first surface includes an exhaust valve. The manufacturing method disclosed herein includes: an injection step, in which the electrolyte is injected into the housing through an injection hole provided in the housing; a charging step, in which charging is performed; a housing placement step, in which the housing is placed on a retaining member; and a sealing step, in which a first pressing clamp presses the third surface along the direction of the first surface with a first load value, and a second pressing clamp presses the pair of second surfaces from both sides with a second load value, thereby sealing the injection hole while deforming the second surfaces in the direction of the inner surface of the housing body. The characteristic feature is that, in the housing placement step, the retaining member has a base portion, and the housing is placed on the retaining member such that the base portion contacts the first surface of the housing body; in the sealing step, the area of ​​the first pressing clamp facing the third surface of the housing body is made of a material with a lower hardness than the retaining member, and the second load value is greater than the first load value.

[0007] According to this manufacturing method, deformation of the first surface of the housing body can be suppressed during the sealing process. Therefore, the sealing process can be performed while suppressing deterioration of the vent valve's operational accuracy. Furthermore, the injection hole is sealed while the second surface of the housing body is deformed towards the inner surface of the housing body. This suppresses the convex expansion of the housing caused by gas generated during the charging and discharging of the energy storage device. Attached Figure Description

[0008] Figure 1 This is a perspective view of an energy storage device according to one embodiment.

[0009] Figure 2 It is along Figure 1 A schematic cross-sectional view of line II-II.

[0010] Figure 3 It is along Figure 1 A schematic cross-sectional view of line III-III.

[0011] Figure 4 yes Figure 1 A 3D view of the energy storage device after it has been reversed.

[0012] Figure 5 This is a schematic diagram showing the structure of the electrode.

[0013] Figure 6 This is a flowchart of a method for manufacturing an energy storage device according to one embodiment.

[0014] Figure 7 This is a perspective view schematically illustrating a retaining component according to one embodiment.

[0015] Figure 8 This is an enlarged view illustrating the housing configuration process involved in one embodiment.

[0016] Figure 9 This is a flowchart of a sub-process of the sealing process according to one embodiment.

[0017] Figure 10 This is a schematic longitudinal sectional view illustrating the sealing process (shell pressing process) involved in this embodiment. Figure 10 This schematically illustrates the state of the housing body before it is pressed down using a pressing clamp. Figure 10 Storage devices and Figure 3 Corresponding to the energy storage equipment.

[0018] Figure 11 This is a schematic longitudinal sectional view illustrating the sealing process (shell pressing process) involved in this embodiment. Figure 11 This schematically illustrates the state of pressing the main body of the housing using a pressing clamp. Figure 11 Storage devices and Figure 3 Corresponding to the energy storage equipment.

[0019] Figure 12 This is a schematic longitudinal sectional view illustrating the sealing process (shell pressing process) involved in this embodiment. Figure 12 This schematically illustrates the state of pressing the main body of the housing using a pressing clamp. Figure 12 Storage devices and Figure 2 Corresponding to the energy storage equipment.

[0020] Figure 13 This is a perspective view of the first pressing clamp involved in this embodiment after it has been reversed vertically.

[0021] Explanation of reference numerals in the attached figures:

[0022] 3…Positive electrode; 4…Negative electrode; 10…Shell; 12…Shell body; 12a…First surface; 12b…Second surface; 12c…Third surface; 12d…Welded joint; 12e…Edge; 12h…Opening; 13…Exhaust valve; 14…Sealing plate; 15…Injection hole; 20…Electrode body; 100…Electrical storage device; 200…Retaining component; 210…Base; 220…Wall; 222…First wall; 224…Second wall; 230…Protrusion; 300…First pressing clamp; 310…Base; 320…Guide; 330…Step; 340…Wall; 342…First wall; 344…Second wall; 400…Second pressing clamp; 410…Pressing part; 420…Base. Detailed Implementation

[0023] Hereinafter, several preferred embodiments of the present disclosure will be described with appropriate reference to the accompanying drawings. Except for matters specifically mentioned in this specification, matters necessary for implementing the present disclosure (e.g., the general structure and manufacturing process of energy storage devices that do not constitute features of the present disclosure) can be grasped by those skilled in the art based on prior art design considerations. This disclosure can be implemented based on the content disclosed in this specification and common general knowledge in the art.

[0024] Furthermore, in the following figures, components and parts that perform the same function are labeled with the same reference numerals, and repeated descriptions may be omitted or simplified. Additionally, the expression "A~B" indicating a range in this specification includes meaning above A and below B, and also includes meaning "more than A and less than B".

[0025] In addition, in the following description, the reference numerals L, R, F, Rr, U, and D in the accompanying drawings represent left, right, front, back, top, and bottom, respectively. The reference numerals X, Y, and Z in the accompanying drawings represent the short side direction of the energy storage device 100, the long side direction orthogonal to the short side direction, and the vertical direction (also called the height direction) orthogonal to both the short and long side directions, respectively. However, these directions are provided for ease of explanation and do not impose any limitations on the arrangement of the energy storage device 100.

[0026] In this specification, "energy storage device" refers to a device that generates charge and discharge by the movement of a charge carrier between a pair of electrodes (positive and negative electrodes) via an electrolyte. Energy storage devices include secondary batteries such as lithium-ion batteries, nickel-metal hydride batteries, and nickel-cadmium batteries, as well as capacitors such as lithium-ion capacitors and double-layer capacitors. Energy storage devices can also be, for example, lithium-ion secondary batteries.

[0027] Figure 1 This is a perspective view of the energy storage device 100 according to one embodiment. Figure 2 It is along Figure 1 A schematic cross-sectional view of line II-II. Figure 3 It is along Figure 1 A schematic cross-sectional view of line III-III. Figure 4 yes Figure 1 This is a three-dimensional view of the energy storage device 100 after it has been reversed. Although the diagram is not shown, the energy storage device 100 here also contains electrolyte. Here, the energy storage device 100 is a lithium-ion secondary battery.

[0028] The housing 10 is a frame that houses the electrode body 20 and the electrolyte. For example... Figure 1 As shown, the housing 10 has a flat, bottomed cuboid shape (square). The housing 10 includes a housing body 12 with one or more openings 12h, and one or more sealing plates 14 for sealing the openings 12h. Figure 2 As shown, the housing 10 of this embodiment includes a housing body 12 and two sealing plates 14. The housing body 12 has a pair of openings 12h at both ends in the long side direction Y (in other words, two openings 12h). The two sealing plates 14 respectively block the pair of openings 12h of the housing body 12.

[0029] As the material for the shell 10, a material with a specified strength can be used without particular restriction. Examples of such materials include metals with aluminum as the main component and metals with iron as the main component (such as SUS).

[0030] Here, the main body 12 of the shell is a hollow square tube. For example... Figure 1 As shown, the main body 12 of the shell has a first surface 12a, a pair of second surfaces 12b, and a third surface 12c. The first surface 12a is approximately rectangular with a pair of long sides and a pair of short sides. The pair of second surfaces 12b extend from the long sides (edges) of the first surface 12a respectively (here, extending upwards) and are opposite each other. The third surface 12c connects the upper ends of the pair of second surfaces 12b to each other and is opposite to the first surface 12a. The area of ​​the second surfaces 12b is larger than the area of ​​the first surface 12a. Here, the area of ​​the second surfaces 12b is also larger than the area of ​​the third surface 12c. Here, the areas of the first surface 12a and the third surface 12c are approximately the same.

[0031] Furthermore, the term "approximately rectangular" in this specification includes not only a complete rectangle (rectangle) but also shapes such as those where the corners connecting the long and short sides of a rectangle are beveled into an R-shape or have notched corners.

[0032] The housing body 12 can be formed, for example, by bending a metal plate into a cylindrical shape and joining the mating parts (e.g., by welding). Therefore, the first surface 12a, the pair of second surfaces 12b, and the third surface 12c are all flat plates with a substantially uniform thickness. Here, a welded joint 12d is provided on the third surface 12c of the housing body 12. In the housing body 12 of this embodiment, the boundary portions (edges) between the second surface 12b and the first surface 12a, and between the second surface 12b and the third surface 12c, are bent portions.

[0033] like Figure 4 As shown, the first surface 12a of the housing body 12 is provided with an exhaust valve 13. The exhaust valve 13 is, for example, a thin-walled portion, configured to rupture when the pressure inside the housing 10 reaches or exceeds a predetermined value, thereby releasing the gas inside the housing 10 to the outside. Furthermore, in this embodiment, the number of exhaust valves 13 is one, but it may also be two or more.

[0034] like Figure 4 As shown, in this embodiment, the exhaust valve 13 has a cross-shaped cutout. However, the shape of the exhaust valve 13 is not particularly limited. In other embodiments, the exhaust valve 13 may be, for example, a linear cutout (only vertical or horizontal lines), or a conventionally known elliptical valve (with a cutout inside), circular valve (with a cutout inside), etc. Furthermore, the dimensions (length, depth, area) of the exhaust valve 13 are arbitrary, and can be appropriately determined, for example, taking into account the pressure resistance of the housing 10.

[0035] The sealing plate 14 is a generally rectangular plate-shaped component. The area of ​​the sealing plate 14 is smaller than the areas of the first surface 12a, the second surface 12b, and the third surface 12c. The sealing plate 14 is flat and has a generally uniform thickness. Figure 1 As shown, a liquid injection hole 15 is provided on one of the sealing plates 14 (here, the R side). The liquid injection hole 15 is used to inject electrolyte into the interior of the housing 10 after the pair of sealing plates 14 are assembled into the housing body 12. The liquid injection hole 15 is sealed by a sealing member 16 after the electrolyte is injected. As the sealing member 16, existing known components can be used without particular limitation. One example of the sealing member 16 is a blind rivet. The liquid injection hole 15 is preferably provided on the sealing plate 14. However, it is not limited thereto; in other embodiments, the liquid injection hole 15 may also be provided on the housing body 12.

[0036] The electrolyte and electrode body 20 are housed together inside the casing 10. The electrolyte can be the same as that used in general energy storage devices and is not particularly limited. Typically, the electrolyte is a non-aqueous liquid electrolyte (non-aqueous electrolyte) containing a non-aqueous solvent and a supporting salt. The non-aqueous solvent includes carbonates such as ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC). The non-aqueous solvent is preferably prepared by mixing EC, EMC, and DMC in the range of 1% to 99% to make the total proportion 100%. The supporting salt is, for example, a fluorinated lithium salt. The fluorinated lithium salt preferably includes lithium hexafluorophosphate (LiPF6), lithium bis(fluorosulfonyl)imide (F2LiNO4S2) known as LiFSI, or mixtures thereof. The concentration of the supporting salt is preferably 0.6 to 1.8 mol per 1 L of non-aqueous solvent.

[0037] The positive terminal 17 and the negative terminal 18 are respectively fixed to the housing 10. Here, the positive terminal 17 and the negative terminal 18 are respectively fixed to the opposite surfaces of the housing 10 (specifically, the sealing plate 14). In detail, the positive terminal 17 is installed on the side disposed in the Y direction of the long side ( Figure 1 , Figure 2 The sealing plate 14 is located on the right side. The negative terminal 18 is installed on the other side, which is positioned in the Y direction along the long side. Figure 1 , Figure 2 The sealing plate 14 is located on the left side. However, this is not a limitation; the positive terminal 17 and the negative terminal 18 can also be mounted on one sealing plate 14 (in other words, one of a pair of sealing plates 14). The positive terminal 17 and the negative terminal 18 are preferably located on the sealing plate 14. However, this is not a limitation; the positive terminal 17 and the negative terminal 18 can also be located on the housing body 12. In addition, in this embodiment, the positive terminal 17 and the negative terminal 18 are located on a different side from the exhaust valve 13. However, this is not a limitation; the positive terminal 17 and the negative terminal 18 can also be located on the same side as the exhaust valve 13.

[0038] The positive terminal 17 and the negative terminal 18 are exposed on the outer surface of the sealing plate 14. Here, the positive terminal 17 and the negative terminal 18 are arranged on an axis extending along the long side direction Y and passing through the center of the sealing plate 14. However, in other embodiments, the axis may also be offset from the center of the sealing plate 14, for example, in the short side direction X. Furthermore, the positive terminal 17 and the negative terminal 18 may not be arranged on the axis. For example, one of the positive terminal 17 and the negative terminal 18 may be offset to one side in the short side direction X, and the other may be offset to the other side in the short side direction X.

[0039] The positive terminal 17 is preferably made of metal, more preferably of aluminum or an aluminum alloy. The negative terminal 18 is preferably made of metal, more preferably of copper or a copper alloy.

[0040] like Figure 2 As shown, the positive terminal 17 is electrically connected inside the housing 10 to the positive terminal 3 (positive electrode tab group 36t) of the electrode body 20 via the positive electrode current collector 38. The negative terminal 18 is electrically connected inside the housing 10 to the negative terminal 4 (negative electrode tab group 46t) of the electrode body 20 via the negative electrode current collector 48. The positive terminal 17 and the negative terminal 18 are insulated from the housing body 12 by an insulating sheet 50.

[0041] The electrode body 20 is housed inside the housing 10. In this embodiment, a plurality of electrode bodies 20 (two in this case) are housed inside one housing 10. However, the number of electrode bodies 20 housed inside one housing 10 is not particularly limited; in other embodiments, there may be more than three or one.

[0042] like Figure 2 and Figure 3 As shown, the electrode body 20 can also be disposed inside the housing body 12 while covered by an insulating sheet 50 (electrode body holder). For example, the insulating sheet 50 is bent into a box shape, and the electrode body 20 is disposed inside the insulating sheet 50. This prevents the electrode body 20 from directly contacting the housing body 12. The insulating sheet 50 is preferably made of resin.

[0043] Figure 5 This is a schematic diagram showing the structure of electrode body 20. (For example...) Figure 5 As shown, the electrode body 20 has a positive electrode 3 and a negative electrode 4. The electrode body 20 is preferably flat. Figure 5 As shown, here, the electrode body 20 is a flat wound electrode body formed by stacking strip-shaped positive electrodes 3 and strip-shaped negative electrodes 4 in an insulated state via strip-shaped diaphragms 27 and winding them around a winding shaft WL. However, the electrode body 20 can 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.

[0044] like Figure 3 As shown, the electrode body 20 has a pair of curved surfaces 21 opposite to the first surface 12a and the third surface 12c of the housing body 12, and a flat surface 22 connecting the pair of curved surfaces 21 and opposite to the second surface 12b of the housing body 12.

[0045] like Figure 5As shown, the positive electrode 3 has a positive current collector 30, a positive active material layer 31 adhered to at least one surface of the positive current collector 30, and a positive protective layer 32. However, the positive protective layer 32 is not essential and may be omitted in other embodiments. The positive current collector 30 is made of conductive metals such as aluminum, aluminum alloy, nickel, and stainless steel, and is preferably made of aluminum or aluminum alloy. The positive active material layer 31 is a layer containing a positive active material capable of reversibly adsorbing and releasing charge carriers. As the positive active material, it is preferably an oxide containing at least one of Ni, Co, and Mn, such as 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 active material preferably contains a composite oxide containing Ni and Li, and is a lithium nickel composite oxide in which the Ni content in the composite oxide is in the range of 70 to 100 mol% relative to the total molar number of constituent elements other than Li and oxygen in the composite oxide. In addition, the positive electrode active material also includes substances obtained by replacing a portion of Ni, Co, and Mn with Al, Ti, Zr, P, B, Si, Nb, C, etc., and substances whose particle surfaces are covered with compounds containing Al, Ti, Zr, W, P, B, Si, Nb, C, etc. The total amount of this replacement and addition relative to the total amount of the positive electrode active material can be between 0.1% and 7%. The positive electrode protective layer 32 is, for example, a layer containing inorganic fillers such as alumina.

[0046] like Figure 5 As shown, the negative electrode 4 has a negative current collector 40 and a negative active material layer 41 adhered to the negative current collector 40. The negative current collector 40 is made of conductive metals such as copper, copper alloys, nickel, and stainless steel, and is preferably made of copper or copper alloys. The negative active material layer 41 is a layer containing a negative active material capable of reversibly absorbing and releasing charge carriers. Examples of negative active materials include carbon materials such as graphite and carbon, and lithium-containing metals and their compounds such as Si, SiO, SiC, and Sn.

[0047] At one end of the positive current collector 30 in the long side direction Y ( Figure 5 Multiple positive electrode tabs 36 are provided at the right end. The multiple positive electrode tabs 36 are respectively oriented towards one side of the long side direction Y ( Figure 5The right side of the diaphragm 27 protrudes. Multiple positive electrode tabs 36 protrude beyond the diaphragm 27 in the long side direction Y. Here, each of the multiple positive electrode tabs 36 is trapezoidal. However, the shape of the positive electrode tabs 36 is not limited to this. Furthermore, the size of the multiple positive electrode tabs 36 is not particularly limited. The shape and size of the positive electrode tabs 36 can be appropriately adjusted, for example, considering their connection with the positive current collector 38 and according to their formation position. The positive electrode tabs 36 are preferably made of metal foil, more preferably of aluminum foil or aluminum alloy foil. Here, the positive electrode tabs 36 are the portions of the positive current collector 30 where the positive active material layer 31 and the positive protective layer 32 are not formed (the so-called exposed portion of the current collector). However, the positive electrode tabs 36 can also be components different from the positive current collector 30.

[0048] At one end of the negative current collector 40 in the Y direction of the long side ( Figure 5 Multiple negative electrode tabs 46 are provided at the left end. These multiple negative electrode tabs 46 face the side along the long side Y direction. Figure 5 The left side of the membrane 47 protrudes. Multiple negative electrode tabs 46 protrude beyond the diaphragm 27 in the long side direction Y. Here, each of the multiple negative electrode tabs 46 is trapezoidal. However, the shape of the negative electrode tabs 46 is not limited to this. Furthermore, the size of the multiple negative electrode tabs 46 is not particularly limited. The shape and size of the negative electrode tabs 46 can be appropriately adjusted, for example, considering their connection with the negative current collector 48 and according to their formation position. The negative electrode tabs 46 are preferably made of metal foil, more preferably of copper foil or copper alloy foil. Here, the negative electrode tabs 46 are the portion of the negative current collector 40 where the negative active material layer 41 is not formed (the so-called exposed portion of the current collector). However, the negative electrode tabs 46 can also be a component different from the negative current collector 40.

[0049] The separator 27 is a component that insulates the positive electrode active material layer 31 of the positive electrode 3 and the negative electrode active material layer 41 of the negative electrode 4. As the separator 27, a porous resin sheet made of polyolefin resins such as polyethylene (PE) or polypropylene (PP) is preferred. Furthermore, a heat resistance layer (HRL) containing inorganic fillers may be provided on the surface of the separator 27. Examples of inorganic fillers used include alumina, boehmite, aluminum hydroxide, and titanium dioxide.

[0050] like Figure 3 and Figure 5 As shown, multiple positive electrode tabs 36 are located at one end in the Y direction of the long side ( Figure 5 The right end of the electrode is stacked to form a positive electrode tab group 36t. On the other hand, multiple negative electrode tabs 46 are stacked at one end in the long side direction Y ( Figure 5The positive electrode group 36t and the negative electrode group 46t are stacked on the left end of the electrode body 20 to form the negative electrode tab group 46t. Here, the energy storage device 100 has a so-called horizontally positioned tab structure, that is, the positive electrode tab group 36t and the negative electrode tab group 46t are located on the left and right sides of the electrode body 20. The positive electrode tab group 36t is bent in the state of being engaged with the positive electrode current collector 38. Similarly, the negative electrode tab group 46t is bent in the state of being engaged with the negative electrode current collector 48.

[0051] The positive current collector 38 forms a conductive path that electrically connects the positive electrode tab group 36t of the electrode body 20 to the positive terminal 17. The positive current collector 38 is preferably made of a metal with excellent conductivity, such as aluminum or an aluminum alloy. The negative current collector 48 forms a conductive path that electrically connects the negative electrode tab group 46t of the electrode body 20 to the negative terminal 18. The negative current collector 48 is preferably made of a metal with excellent conductivity, such as copper or a copper alloy.

[0052] <Manufacturing Method of Energy Storage Device 100>

[0053] The method for manufacturing the energy storage device 100 disclosed herein is characterized by including a liquid injection step, a charging step, a housing assembly step, and a sealing step. In addition to the steps described above, the method for manufacturing the energy storage device 100 disclosed herein may also include other steps at any stage. Figure 6 This is a flowchart illustrating a method for manufacturing an energy storage device 100 according to one embodiment. While not particularly limiting, however… Figure 6 As shown, the energy storage device 100 can typically be manufactured by a manufacturing method comprising, in sequence, (1) an assembly preparation step S10, (2) a drying step S20, (3) a liquid injection step S30, (4) a charging step S40, (5) a pressure reduction step S50, (6) a housing configuration step S60, and (7) a sealing step S70. The manufacturing method of the energy storage device disclosed herein is characterized by the housing configuration step S60 and the sealing step S70; the other manufacturing processes can be the same as those in existing methods.

[0054] (1) Assembly preparation process S10

[0055] In the assembly preparation step S10, the electrode body 20 is placed inside the housing 10 (housing body 12) to prepare the assembly. Furthermore, in this specification, "assembly" refers to an energy storage device assembled to its state before the charging step S40 described later.

[0056] In the assembly preparation step S10, for example, a housing 10 (sealing plate 14 and housing body 12), an electrode body 20, a positive terminal 17, a negative terminal 18, a positive current collector 38, a negative current collector 48, and an insulating sheet 50 are prepared. The energy storage device 100 disclosed herein is characterized by the housing 10 (housing body 12 and sealing plate 14), and the structure thereafter may be the same as in the prior art.

[0057] The shell body 12 prepared in the assembly preparation step S10 has a first surface 12a, a pair of second surfaces 12b, a third surface 12c, and one or more openings 12h. The first surface 12a is a generally rectangular shape with a pair of long sides and a pair of short sides, and has an exhaust valve 13. The pair of second surfaces 12b extend from the pair of long sides of the first surface 12a, and their areas are larger than the area of ​​the first surface 12a. The third surface 12c is opposite to the first surface 12a. In this embodiment, a hollow, cylindrical shell body 12 with openings 12h at both ends in the long side direction Y is prepared. The shell body 12 is preferably made of metal and is composed of a metal material with aluminum as the main component. In addition, "metal material with aluminum as the main component" in this specification refers to a metal material containing aluminum accounting for more than 90% of the total weight, such as aluminum, aluminum alloys, etc.

[0058] The first surface 12a, the pair of second surfaces 12b, and the third surface 12c are preferably flat plates with substantially uniform thickness. The thickness of the shell body 12 (the thickness of the metal plate) is preferably 2.5 mm or less, more preferably 1.5 mm or less, and even more preferably 1.0 mm or less. The lower limit of the thickness of the shell body 12 is not particularly limited, but can be, for example, 0.5 mm or more.

[0059] Furthermore, the housing body 12 can be a commercially available product or manufactured using existing known methods. The housing body 12 can be formed, for example, by bending a metal sheet into a cylindrical shape and joining the mating parts (e.g., by welding). This results in a housing body 12 with a first surface 12a, a pair of second surfaces 12b, and a third surface 12c, each being a flat plate with a substantially uniform thickness. When forming the housing body 12 using this method, it is preferable to join the mating parts at the third surface 12c. In other words, it is preferable to form a welded joint 12d at the third surface 12c. The hardness of the welded joint 12d is relatively lower than that of the first surface 12a and the second surface 12b. Therefore, by forming the welded joint 12d at the third surface 12c, the expansion force on the first surface 12a generated when pressing the housing 10 can be released more appropriately. However, not limited to the above method, the housing body 12 can also be formed by joining multiple metal sheets.

[0060] The sealing plate 14 prepared in the assembly preparation step S10 is preferably made of metal, and is composed of a metal material with aluminum as the main component. Furthermore, the thickness of the sealing plate 14 is preferably greater than the thickness of the housing body 12. Therefore, the sealing plate 14 has a certain degree of strength, which can suppress deformation of the housing 10 in the direction of the sealing plate 14 (long side direction Y) during the sealing step S70 described later. The thickness of the sealing plate 14 is preferably 1.5 mm or more, more preferably 1.8 mm or more, and even more preferably 2.0 mm or more. With the sealing plate 14 having the above structure, deformation of the sealing plate 14 can be suppressed during the sealing step S70 described later, and on the other hand, the third surface 12c of the housing body 12 can be deformed more easily and appropriately. Therefore, deformation of the exhaust valve 13 of the housing body 12 can be suppressed more effectively. The upper limit of the thickness of the sealing plate 14 is not particularly limited, but can be, for example, 10.0 mm or less. The sealing plate 14 is preferably equipped with a positive terminal 17 and a negative terminal 18. In this embodiment, a sealing plate 14 with a positive terminal 17 and a sealing plate 14 with a negative terminal 18 are prepared respectively.

[0061] The shell body 12 and the sealing plate 14 are preferably made of the same type of material, and are particularly preferably made of a metal material with aluminum as the main component. However, the shell body 12 and the sealing plate 14 may also be made of different materials.

[0062] The electrode body 20 can be a commercially available product or manufactured using existing known methods. Here, the electrode body 20 is prepared to be housed within an insulating sheet 50 bent into a box shape. In the assembly preparation step S10, the negative electrode current collector 48 is installed onto the negative electrode tab assembly 46t. Next, the negative electrode current collector 48 is joined to the negative terminal 18 mounted on the sealing plate 14 using existing known methods (e.g., ultrasonic bonding, resistance welding, laser welding, etc.). Thus, the electrode body 20 and the sealing plate 14 are integrated. Next, the electrode body 20 is housed (inserted) into the housing body 12 from the positive electrode tab assembly 36t side. Afterward, the positive electrode current collector 38 is installed onto the positive electrode tab assembly 36t of the electrode body 20. Next, the positive electrode current collector 38 is joined to the positive terminal 17 mounted on the sealing plate 14 using existing known methods (e.g., ultrasonic bonding, resistance welding, laser welding, etc.). The assembly can then be manufactured by joining the housing body 12 to the sealing plate 14. This joining can be performed, for example, by welding such as laser welding.

[0063] In the assembly preparation step S10, it is preferable to arrange the electrode body 20 inside the housing body 12 such that the thickness (stack) direction of the electrode body 20 is approximately perpendicular to the second surface 12b (orthogonal to the second surface 12b). In other words, it is preferable to arrange the electrode body 20 inside the housing 10 such that the thickness direction of the housing 10 is aligned with the thickness direction of the electrode body 20 (short side direction X). When the electrode body 20 is a wound electrode body, it is preferable to arrange the electrode body 20 inside the housing body 12 such that the winding axis WL of the electrode body 20 is parallel to the first surface 12a of the housing body 12. In other words, it is preferable to arrange the electrode body 20 inside the housing body 12 such that a pair of curved surfaces 21 of the electrode body 20 are respectively opposite to the first surface 12a and the third surface 12c of the housing body 12. As a result, a gap is easily generated between the second surface 12b and the curved surfaces 21 of the electrode body 20, and the housing 10 (housing body 12) is easily deformed into the desired shape.

[0064] (2) Drying process S20

[0065] In the drying process S20, moisture contained in the assembly (e.g., the interior of the electrode body 20) is removed by drying the assembly. This drying method can be carried out using known methods. For example, the drying process S20 can be carried out by conveying the assembly (the housing 10 containing the electrode body 20) to a drying oven (not shown) and heating it.

[0066] The drying temperature and drying time in drying step S20 can be appropriately adjusted according to the moisture content of the electrode body 20. The drying temperature is not particularly limited as long as it is within a range that allows moisture removal, but drying is preferably performed at a temperature that does not damage the diaphragm 27 of the electrode body 20. Furthermore, drying step S20 can be performed under atmospheric pressure or under reduced pressure. Drying step S20 is preferably performed under reduced pressure. This shortens the drying time of drying step S20. Moreover, in the technology disclosed herein, drying step S20 is not a necessary step. In some preferred embodiments, drying step S20 may be omitted.

[0067] (3) Liquid injection process S30

[0068] In the electrolyte injection step S30, electrolyte is injected into the housing 10 containing the electrode body 20 through the injection hole 15 provided on the sealing plate 14. The electrolyte injection step S30 can be performed under atmospheric pressure or under reduced pressure. While not limited to either, it is preferable to perform the electrolyte injection step S30 under reduced pressure. This improves the permeability of the electrolyte into the electrode body 20, allowing the electrolyte injection step S30 to be performed in a shorter time. During the electrolyte injection process, the amount of injected electrolyte should be sufficient to distribute the electrolyte throughout the entire electrode body 20. Existing known electrolyte injection devices can be appropriately used for the electrolyte injection step S30. Furthermore, the pressurizing gas used for pressurizing the electrolyte can be, as with the prior art, inert gases such as nitrogen (N2) or dry air. After the electrolyte injection step S30 is completed, it is preferable to appropriately pressurize and depressurize the housing 10.

[0069] (4) Charging process S40

[0070] In charging step S40, the assembly is charged. By performing charging step S40, a high-quality film can be formed on the surface of the negative electrode active material layer 41. The gas generated in charging step S40 is released outside the housing 10. The charging conditions in this step are not particularly limited and can be the same as those in existing energy storage devices. In charging step S40, the liquid injection hole 15 can also be temporarily sealed. However, in charging step S40, the liquid injection hole 15 is not completely sealed.

[0071] (5) Pressure reduction process S50

[0072] In the pressure reduction step S50, by reducing the pressure inside the housing 10, the gas present inside the housing 10 (e.g., air, gas generated in the charging step S40 described above) is further discharged to the outside of the housing 10. This pressure reduction step S50 can be the same as the pressure reduction step S50 in the manufacturing method of existing energy storage devices, and does not specifically represent the technology disclosed herein; therefore, a more detailed description is omitted. Furthermore, in the technology disclosed herein, the pressure reduction step S50 is not a necessary step. In some preferred embodiments, the pressure reduction step S50 may also be omitted.

[0073] (6) Housing assembly process S60

[0074] In the housing configuration step S60, the housing 10 is configured on the retaining member 200. In this embodiment, firstly, the retaining member 200 for the housing configuration step S60 is prepared. Figure 7 This is a perspective view schematically illustrating the holding member 200 according to one embodiment. Figure 8 This is an enlarged view illustrating the housing configuration process S60 of one embodiment. (See diagram below.) Figure 7As shown, the retaining member 200 of this embodiment includes a base portion 210, a wall portion 220, and a protrusion 230.

[0075] The retaining member 200 is preferably made of a metal such as chromium-molybdenum steel. The retaining member 200 is made of a material with a hardness higher than that of the guide portion 320 of the first pressing clamp 300 described later. Here, the retaining member 200 is composed of a single component. However, the structure of the retaining member 200 is not limited to this; for example, a component formed by joining the wall portion 220 and the protrusion 230 to the base portion 210 may also be used. Furthermore, in this specification, "hardness" refers to the Vickers hardness measured according to JIS Z2244:2009.

[0076] Here, the base portion 210 is a generally rectangular plate-shaped portion extending along the XY plane. In the housing arrangement process S60, the housing 10 is arranged on the retaining member 200 such that the base portion 210 contacts the first surface 12a of the housing body 12.

[0077] The length of the base portion 210 in the long side direction Y is not particularly limited, but it is preferably approximately the same as (e.g., ±0.5 mm) or greater than the length of the first surface 12a of the shell 10 in the long side direction Y. Similarly, the length of the base portion 210 in the short side direction X is not particularly limited, but it is preferably approximately the same as (e.g., ±0.1 mm) or greater than the length of the first surface 12a of the shell 10 in the short side direction X. The area of ​​the base portion 210 is preferably the same as or greater than the area of ​​the first surface 12a of the shell 10. This allows for appropriate suppression of deformation of the first surface 12a of the shell body 12.

[0078] The retaining member 200 according to this embodiment also includes a wall portion 220 extending upward from the end of the base portion 210. Here, the wall portion 220 includes a pair of first wall portions 222 and a pair of second wall portions 224. The pair of first wall portions 222 extend from each end (long side portion) of the base portion 210 in the short side direction X in a direction orthogonal to the base portion 210 (U direction) and are opposite to each other. Here, the pair of first wall portions 222 are configured such that when the housing 10 is disposed on the retaining member 200, the inner surface of the first wall portion 222 abuts against the second surface 12b of the housing body 12 (see reference). Figure 10 Therefore, in the sealing process S70 described later, the movement of the housing 10 in the short-side direction X can be restricted. Thus, the sealing process S70 can be performed more easily. A pair of second wall portions 224 extend from each end (short-side portion) of the base portion 210 in the long-side direction Y towards a direction orthogonal to the base portion 210 (U direction), and are opposite to each other. Here, the pair of second wall portions 224 are configured such that when the housing 10 is placed on the retaining member 200, the inner surface of the second wall portion 224 abuts against the sealing plate 14 (see reference). Figure 12Therefore, in the sealing process S70 described later, the movement of the housing 10 in the long side direction Y can be restricted. Thus, the sealing process S70 can be performed more easily. The wall portion 220 can also be configured to have only one pair of first wall portions 222 or one pair of second wall portions 224.

[0079] The height H of the wall section is 220. w1 Not particularly limited, but from the viewpoint of appropriately limiting the movement of the housing 10 in the short-side direction X, it is preferably 5 mm or more, more preferably 10 mm or more. The height H of the wall portion 220 w1 The upper limit is not particularly limited, but from the viewpoint of pressing the second surface 12b of the housing 10 with the second pressing clamp 400, it is preferably 15 mm or less, more preferably 10 mm or less. In addition, in this specification, "the height of the wall portion 220" refers to the length of the perpendicular line drawn from the end of the wall portion 220 to the surface of the base portion 210 opposite to the first surface 12a.

[0080] The protrusion 230 is a portion that protrudes from the base portion 210 in the U-direction. Here, the protrusion 230 protrudes along the extending direction of the wall portion 220. For example... Figure 7 and Figure 4 As shown, the protrusion 230 is formed to correspond to the shape of the exhaust valve 13 (here, it is cross-shaped). Figure 8 As shown, in the housing configuration step S60, the housing 10 is configured on the retaining member 200 such that the protrusion 230 engages with the exhaust valve 13 of the housing body 12. Therefore, in the housing pressing step S72 described later, deformation of the exhaust valve 13 can be appropriately suppressed, in addition to the first surface 12a. Thus, the deterioration of the operating accuracy of the exhaust valve 13 can be further suppressed.

[0081] Height H of convex portion 230 p Able to determine the groove depth V of the exhaust valve 13 g Adjust appropriately (refer to) Figure 8 Typically, the height H of the protrusion 230 of the retaining component 200 is maintained. p The groove depth V of the exhaust valve 13 g The groove depth V is the same as or less than that of exhaust valve 13. g (H) p ≤V g ). Height H of convex portion 230 p The groove depth V relative to the exhaust valve 13 g The ratio (H) p / V gThe value is preferably 0.1 to 1.0, more preferably 0.8 to 1.0. Therefore, in the housing pressing process S72 described later, deformation of the exhaust valve 13 can be appropriately suppressed, in addition to the first surface 12a. The shape of the protrusion 230 can be appropriately changed according to the shape of the exhaust valve 13.

[0082] (7) Sealing process S70

[0083] In the sealing process S70, the injection hole 15 is sealed while the third surface 12c of the housing 10 is pressed along the direction of the first surface 12a by the first pressing clamp 300 with a first load value and the second surface 12b is pressed from both sides by the second pressing clamp 400 with a second load value. Figure 9 This is a flowchart of a sub-process of the sealing process S70 according to one embodiment. For example... Figure 9 As shown, the sealing process S70 in this embodiment sequentially includes a housing pressing process S72 and a liquid injection hole sealing process S74 as sub-processes. Furthermore, an aging process may be included before or after the sealing process S70 (before the housing pressing process S72 or after the liquid injection hole sealing process S74). This aging process can be the same as the aging process in existing manufacturing methods for such energy storage devices, and does not specifically characterize the technology disclosed herein; therefore, a more detailed description is omitted.

[0084] (7―1) Shell pressing process S72

[0085] In the housing pressing process S72, the third surface 12c of the housing 10 is pressed along the direction of the first surface 12a (here, the D direction) using the first pressing clamp 300 with a first load value. On the other hand, the second surface 12b is pressed from both sides (clamping direction) using the second pressing clamp 400 with a second load value. Furthermore, in this embodiment, the sealing plate 14 of the housing 10 is not pressed by the pressing clamp.

[0086] Figures 10-12 This is a schematic longitudinal sectional view illustrating the sealing process S70 (casing pressing process) involved in this embodiment. Figure 10 The illustration shows the state before the housing body 12 is pressed using pressing clamps (first pressing clamp 300 and second pressing clamp 400). Figure 11 and Figure 12 This schematically illustrates the state in which the housing body 12 is pressed using a pressing clamp. Figure 10 and Figure 11 Storage device 100 and Figure 3 The energy storage device corresponds to 100. Figure 12 Storage device 100 and Figure 2 The energy storage device corresponds to 100. In Figure 11 and Figure 12In the diagram, the pressing direction of the first pressing clamp 300 is indicated by a black arrow, and the pressing direction of the second pressing clamp 400 is indicated by a white arrow. For ease of explanation, in... Figure 12 In the diagram, an imaginary line represents region A where the second pressing clamp 400 is configured (in other words, the region pressed by the second pressing clamp 400).

[0087] In this embodiment, firstly, a pressing fixture is prepared as a pressing fixture for performing the housing pressing process S72, such as... Figures 10-12 The first pressing clamp 300 and a pair of second pressing clamps 400 are shown as shown.

[0088] Figure 13 This is a perspective view of the first pressing clamp 300 involved in this embodiment after being reversed vertically. (See image below.) Figure 10 and Figure 13 As shown, the first pressing clamp 300 of this embodiment includes a base 310, a guide portion 320, a step portion 330, and a wall portion 340. Furthermore, the guide portion 320 is an example of "the area in the first pressing clamp 300 that faces the third surface 12c of the housing body 12" in this specification.

[0089] In the first pressing clamp 300 of this disclosure, the region (guide portion 320) of the first pressing clamp 300 opposite to the third surface 12c of the housing body 12 is made of a material with a lower hardness than the holding member 200. Although this will be described in detail later, it allows the third surface 12c of the housing body 12 to deform (expand) outward (in the U direction) during the housing pressing process S72. The guide portion 320 is preferably made of a material that deforms under stress. As this material, resin is preferred, and more preferably polyurethane, acrylic polyurethane, etc.

[0090] Furthermore, the materials of the portions constituting the first pressing clamp 300 other than the area where the first pressing clamp 300 faces the third surface 12c of the housing body 12 (base 310, stepped portion 330, and wall portion 340) are not particularly limited and can be the same as or different from the guide portion 320. Moreover, the portions of the first pressing clamp 300 other than the area where the first pressing clamp 300 faces the third surface 12c of the housing body 12 are preferably made of a material with a higher hardness than the guide portion 320. This makes it easier to press the first pressing clamp 300 along the direction of the first surface 12a of the housing body 12. As this material, metals such as chromium-molybdenum steel are preferred. Furthermore, the guide portion 320 is one example of a "first component" in this specification. Additionally, the base 310, stepped portion 330, and wall portion 340 are one example of a "second component that is relatively harder than the first component" in this specification. Figure 10As shown, in this embodiment, the guide portion 320 (first component) in the first pressing clamp 300 is made of resin (polyurethane), and the portion other than the guide portion 320 (second component) is made of metal.

[0091] The base 310 is a generally rectangular flat portion extending along the XY plane. A guide portion 320 is formed on one side of the base 310. Although not shown in the figure, a drive device such as a cylinder for driving the first pressing clamp 300 may be connected to the other side of the base 310.

[0092] like Figure 10 , Figure 12 as well as Figure 13 As shown, the guide portion 320 is a generally rectangular flat portion extending along the XY plane. The length of the guide portion 320 in the long side direction Y is not particularly limited, but it is preferably approximately the same as or greater than the length of the third surface 12c of the housing 10 in the long side direction Y. It is not limited to the case where, when the area of ​​the third surface 12c of the housing 10 is 100%, the area of ​​the guide portion 320 is preferably 80% or more, more preferably 95% or more. Furthermore, when the area of ​​the third surface 12c of the housing 10 is 100%, the area of ​​the guide portion 320 is preferably 100% or less, more preferably 98% or less. Therefore, in the housing pressing process S72, the third surface 12c of the housing body 12 can be appropriately promoted to deform (expand) outward (in the U direction).

[0093] Thickness T of guide section 320 g (Thickness in the vertical Z direction) (Reference) Figure 10 The thickness T of the guide portion 320 is not particularly limited, but is preferably 10 mm or more, and more preferably 15 mm or more. This allows for appropriate outward (U-direction) deformation (expansion) of the third surface 12c of the housing body 12 during the housing pressing process S72. On the other hand, the thickness T of the guide portion 320... g The upper limit of the thickness (Z in the vertical direction) is not particularly limited, but it can be, for example, less than 50 mm.

[0094] like Figure 10 as well as Figure 13 As shown, the first pressing clamp 300 according to this embodiment also includes stepped portions 330 that protrude from each end of the guide portion 320 in the short side direction X toward the housing body 12 in the direction D. Figure 13 As shown, the step portion 330 is located between the guide portion 320 and the first wall portion 342. Figure 13 As shown, the stepped portion 330 extends along the long side direction Y. Specifically, the stepped portion 330 is configured as a pair of edge portions 12e (and the vicinity of the edge portions 12e) where the third surface 12c of the pressing housing body 12 intersects with a pair of second surfaces 12b. As... Figure 10As shown, in this embodiment, the stepped portion 330 protrudes towards the housing body 12 in the direction of D compared to the guide portion 320. Therefore, the stepped portion 330 is configured to contact the edge portion 12e before the guide portion 320. According to this structure, in the housing pressing process S72, the housing 10 can be pressed more reliably along the direction of the first surface 12a. Therefore, it is possible to suppress the housing 10 from floating in the height direction Z.

[0095] The width W of the stepped portion 330 in the short side direction X s (Reference Figure 10 The height H of the step portion 330 is not particularly limited, but from the viewpoint of ensuring reliable contact between the edge portion 12e and the step portion 330, it is preferably 1.0 mm or more, and more preferably 5.0 mm or more. s (Reference Figure 10 While not particularly limited, from the viewpoint of promoting outward (U-direction) deformation (expansion) of the third surface 12c of the housing 10, a height H of 10mm or more is preferred, and more preferably 20mm or more. On the other hand, while not particularly limited, from the viewpoint of ensuring more reliable contact between the edge portion 12e of the housing 10 and the step portion 330, the height H of the step portion 330 is... s Preferably, it is 50mm or less, and more preferably 30mm or less.

[0096] The first pressing clamp 300 according to this embodiment also includes a wall portion 340 extending upward from the end of the base portion 310. For example... Figure 10 and Figure 12 As shown, here, the wall portion 340 includes a pair of first wall portions 342 and a pair of second wall portions 344. The pair of first wall portions 342 extend from each end (long side portion) of the base portion 310 in the short side direction X towards a direction orthogonal to the base portion 310 (direction D), and are opposite to each other. Figure 10As shown, the pair of first wall portions 342 protrude beyond the stepped portion 330. Here, the pair of first wall portions 342 are configured such that when the housing 10 is pressed by the first pressing clamp 300, the inner surface of the first wall portion 342 abuts against the second surface 12b of the housing body 12. This allows the sealing process S70 to be performed while the first pressing clamp 300 is fixed in the short-side direction X. This also allows for more reliable pressing of the housing body 12 by the first pressing clamp 300. The pair of second wall portions 344 extend from each end (short side portion) of the base 310 in the long-side direction Y towards a direction orthogonal to the base 310 (direction D), and are opposite each other. Here, the pair of second wall portions 344 are configured such that when the housing 10 is pressed by the first pressing clamp 300, the inner surface of the second wall portion 344 abuts against the sealing plate 14. Therefore, the sealing process S70 can be performed while the first pressing clamp 300 is fixed in the long side direction Y. This allows for more reliable pressing of the housing body 12 by the first pressing clamp 300. The wall portion 340 can also be configured to have only one pair of first wall portions 342 or one pair of second wall portions 344.

[0097] The wall height H is 340. w2 Not particularly limited, but from the viewpoint of appropriately limiting the movement of the housing 10 in the short-side direction X, it is preferably 50 mm or more, more preferably 100 mm or more. The height H of the wall portion 340 w2 The upper limit is not particularly limited, but from the viewpoint of pressing the second surface 12b of the housing 10 with the second pressing clamp 400, it is preferably 500 mm or less, more preferably 300 mm or less. In addition, in this specification, "the height of the wall portion 340" refers to the length of the perpendicular line drawn from the end of the wall portion 340 to the surface of the guide portion 320 opposite to the third surface 12c.

[0098] like Figure 10 As shown, the second pressing clamp 400 of this embodiment includes a pressing portion 410 and a base 420. The pressing portion 410 is a portion that contacts a pair of second surfaces 12b of the housing body 12. Here, the pressing portion 410 is formed flat along the pair of second surfaces 12b of the housing body 12 (on the YZ plane). The base 420 is a flat plate-shaped portion extending along the YZ plane. Here, the pressing portion 410 is formed on one side of the base 420. However, it is not limited to this, the pressing portion 410 may also be a convex curved surface (R-shaped) that bends toward the second surface 12b. Although not shown in the figure, a drive device for driving the clamping device or the second pressing clamp 400 may also be connected to the other side of the base 420.

[0099] The material constituting the second pressing clamp 400 is not particularly limited. When the second pressing clamp 400 has a pressing part 410 and a base 420, the base 420 is preferably made of a material with a higher hardness than the pressing part 410. This allows sufficient load to be applied to the second surface 12b of the housing body 12 via the base 420, and protects the surface of the second surface 12b of the housing body 12 via the pressing part 410. The pressing part 410 is preferably made of resin, and the base 420 is preferably made of metal. Examples of materials constituting the pressing part 410 include polypropylene. Examples of materials constituting the base 420 include duralumin. The pressing part 410 may also be made of a material that deforms when pressing the housing 10.

[0100] like Figure 10 As shown, in the housing pressing process S72, a first pressing clamp 300 is arranged to cover the third surface 12c. Here, the first pressing clamp 300 is arranged such that the third surface 12c faces the guide portion 320 and the edge portion 12e faces the step portion 330. On the other hand, a pair of second pressing clamps 400 are arranged to clamp a pair of second surfaces 12b of the housing body 12 from both sides. Here, a pair of second pressing clamps 400 are arranged such that the second surface 12b faces the pressing portion 410.

[0101] Then, as Figure 11 As shown, the second pressing clamp 400 presses a pair of second surfaces 12b of the housing body 12 towards the inside of the housing body 12 (in other words, the clamping direction of the second pressing clamp 400 or the direction of the electrode body 20) from both sides with a second load value (in the direction of the white arrow). In other words, the portion of the second surface 12b that abuts against the second pressing clamp 400 (the pressing portion 410) is pushed towards the inside of the housing body 12 (the electrode body 20 side). Therefore, as... Figure 11 As shown, each of the second surfaces 12b is deformed toward the inner surface of the housing body 12 (towards the electrode body 20) (in other words, in a recessed manner).

[0102] Here, in the manufacturing of a typical energy storage device 100, as the aforementioned housing body 12 deforms along one pair of second surfaces 12b, the housing body 12 deforms by expanding in the height direction Z. In other words, the first surface 12a of the housing body 12 bends outward (in the D direction), and the third surface 12c bends outward (in the U direction). When the housing 10 has an exhaust valve 13 on the first surface 12a, the deformation of the first surface 12a may cause the exhaust valve 13 to fail to operate with good precision.

[0103] In this manufacturing method, in addition to pressing the second surface 12b as described above, a first pressing clamp 300 is used to apply a first load value along the direction of the first surface 12a. Figure 11The third surface 12c of the housing body 12 is pressed in the Z direction (in the direction of the black arrow). This suppresses the floating of the housing 10 in the vertical Z direction. At this time, a force is generated that presses the first surface 12a against the holding member 200. This suppresses the outward deformation (expansion) of the first surface 12a in the D direction. On the other hand, the guide portion 320 of the first pressing clamp 300 is made of a material with a lower hardness than the holding member 200. Therefore, the outward deformation (expansion) of the third surface 12c of the housing body 12 is not suppressed by the guide portion 320. Therefore, the force that deforms the housing body 12 in the height Z direction acts on the third surface 12c, causing the third surface 12c to deform outward (in the U direction). According to this method, the deformation of the first surface 12a can be suppressed, and the deformation of one pair of second surfaces 12b of the housing body 12 can be achieved (see reference). Figure 11 and Figure 12 ).

[0104] The magnitude of the first load (in terms of pressure) can be appropriately varied depending on the size of the housing 10 and the material constituting the housing 10. Not limited to this, the magnitude of the first load (in terms of pressure) is preferably 1 kN or more, more preferably 2 kN or more, and even more preferably 3 kN or more. On the other hand, the magnitude of the first load (in terms of pressure) is preferably 6 kN or less, more preferably 5 kN or less, and even more preferably 4 kN or less.

[0105] In the manufacturing method disclosed herein, the magnitude of the second load is greater than the first load. This prevents the first surface 12a of the housing 10 from floating in the vertical direction Z towards the U direction and suppresses the expansion of the housing 10. The magnitude of the second load (in terms of pressure) can be appropriately varied depending on the size of the housing 10 and the material constituting the housing 10. Not limited to this, the magnitude of the second load (in terms of pressure) is preferably 1 kN or more, more preferably 5 kN or more, and even more preferably 10 kN or more. On the other hand, the magnitude of the second load (in terms of pressure) is preferably 40 kN or less, more preferably 30 kN or less, and even more preferably 20 kN or less.

[0106] For the pair of second surfaces 12b of the housing body 12, the pressing amount of the second pressing clamp 400 is preferably 0.5 to 5 mm, more preferably 0.5 to 2 mm. This allows for appropriate suppression of the housing 10 expanding into a convex shape during charging and discharging of the energy storage device 100. Furthermore, in this specification, "pressing amount" refers to the thickness (distance) T0 of the housing 10 in the short-side direction X before the housing pressing process S72 (refer to...). Figure 10 The thickness T1 of the housing 10 in the short side direction X during the housing pressing process S72 (refer to...) Figure 11The difference between the thicknesses (i.e., T0-T1) is the thickness of the region with the smallest thickness (distance) of the shell 10 during the shell pressing process S72 (in other words, the part where the second surface 12b is pressed in the most). In the top view, the region A of the shell 10 pressed by the second pressing fixture 400 preferably includes the region containing the positive electrode active material layer 31 in the flat portion 22 of the electrode body 20.

[0107] When the housing body 12 has a welded joint 12d, the welded joint 12d is preferably provided on the third surface 12c. Moreover, it is preferable to perform the housing pressing process S72 with the welded joint 12d facing the guide portion 320 of the first pressing clamp 300. With this structure, the housing pressing process S72 can be performed while protecting the welded joint 12d through the guide portion 320.

[0108] (7-2) Sealing process for injection hole S74

[0109] In the liquid injection hole sealing process S74, the liquid injection hole 15 of the housing 10 is sealed while the housing body 12 is pressed down by the housing pressing process S72 (in other words, the second surface 12b of the housing body 12 is deformed towards the inner surface of the housing body 12). This seals the liquid injection hole 15 while reducing the internal volume of the housing 10. Therefore, it is possible to suppress the expansion of the housing 10 in the thickness direction (short side direction X) due to gas generated during charging and discharging of the energy storage device 100. Here, the liquid injection hole 15 is sealed by a metal sealing member 16, and the metal portion of the sealing member 16 is welded to the housing 10, thereby sealing the liquid injection hole 15. However, the sealing method for the liquid injection hole 15 is not limited to this. Although not shown in the figure, the liquid injection hole 15 can also be sealed by a rivet, such as a blind rivet.

[0110] As described above, the manufacturing method of the energy storage device 100 disclosed herein can suppress the deterioration of the operating accuracy of the vent valve caused by pressing the housing 10. Furthermore, in the case of the energy storage device 100 manufactured by this method, the expansion of the housing 10 caused by gas generated during charging and discharging can be suppressed.

[0111] The energy storage device 100 can be used for various purposes, but typically, it is preferred as a power source (drive power supply) for motors in various vehicles, such as passenger cars and trucks. The type of vehicle is not particularly limited; examples include plug-in hybrid electric vehicles (PHEVs), hybrid electric vehicles (HEVs), and battery electric vehicles (BEVs). Furthermore, the energy storage device 100 can also be suitably used to construct energy storage modules.

[0112] The above description illustrates several embodiments of the technology disclosed herein, but these embodiments are merely examples. The technology disclosed herein can be implemented in many other ways. The technology disclosed herein can be implemented based on the content disclosed in this specification and common knowledge in the art. The technology described in the technical solutions includes various modifications and alterations to the embodiments illustrated above. For example, a portion of the above embodiments can be replaced with other modifications, or other modifications can be added to the above embodiments. Furthermore, any technical feature not explicitly stated as essential can be appropriately deleted.

[0113] As described above, the following are examples of specific ways of describing the technology disclosed herein.

[0114] <Item 1>

[0115] A method for manufacturing an energy storage device, the energy storage device comprising an electrode body including a positive electrode and a negative electrode, an electrolyte, and a housing containing the electrode body and the electrolyte, wherein...

[0116] The aforementioned housing comprises:

[0117] The shell body comprises a generally rectangular first face having a pair of long sides and a pair of short sides, a pair of second faces extending from the pair of long sides and having an area larger than the first face, a third face opposite the first face, and one or more openings; and

[0118] One or more sealing plates that seal one or more of the aforementioned openings.

[0119] The first side mentioned above is equipped with an exhaust valve.

[0120] The manufacturing method of the above-mentioned energy storage device includes the following steps:

[0121] In the liquid injection process, the electrolyte is injected into the housing through the liquid injection hole provided in the housing.

[0122] The charging process involves charging.

[0123] The housing configuration process involves configuring the aforementioned housing onto the retaining member; and

[0124] In the sealing process, the third surface is pressed along the direction of the first surface using a first pressing clamp with a first load value, and the pair of second surfaces are pressed from both sides using a second pressing clamp with a second load value, causing the second surfaces to deform in the direction of the inner surface of the housing body, thereby sealing the injection hole.

[0125] In the aforementioned shell configuration process,

[0126] The aforementioned retaining component includes a base portion.

[0127] The housing is disposed on the retaining member such that the base portion contacts the first surface of the housing body.

[0128] In the above sealing process,

[0129] The area of ​​the first pressing clamp that faces the third face of the housing body is made of a material with a lower hardness than the retaining member.

[0130] The second load value is greater than the first load value.

[0131] <Item 2>

[0132] In the method for manufacturing the energy storage device described in item 1,

[0133] The aforementioned first pressing clamp includes a first component and a second component with a higher hardness than the first component.

[0134] The sealing process is performed by having the first component of the first pressing clamp contact the third surface of the housing body.

[0135] <Item 3>

[0136] In the manufacturing method of the energy storage device described in item 1 or 2,

[0137] The aforementioned first pressing clamp has a stepped portion.

[0138] The third surface is pressed by the first pressing clamp in such a way that the stepped portion presses the edge portion where the third surface of the housing intersects with the pair of second surfaces.

[0139] <Item 4>

[0140] In any of the manufacturing methods of the energy storage device described in items 1 to 3,

[0141] The aforementioned retaining component also has a protrusion.

[0142] The housing configuration process is performed by fitting the aforementioned protrusion into the aforementioned exhaust valve of the housing body.

[0143] <Item 5>

[0144] In any of the manufacturing methods of the energy storage device described in items 1 to 4,

[0145] The second pressing clamp described above includes a pressing part and a base with a hardness higher than that of the pressing part.

[0146] The sealing process is performed by having the pressing part of the second pressing clamp contact the second surface.

[0147] <Item 6>

[0148] In any of the manufacturing methods of the energy storage device described in items 1 to 5,

[0149] The aforementioned retaining member also includes a pair of wall portions extending upward from the aforementioned base portion.

[0150] The housing configuration process is performed such that the pair of wall portions of the retaining member contact the pair of second surfaces of the housing body respectively.

[0151] <Item 7>

[0152] In any of the manufacturing methods of the energy storage device described in items 1 to 6,

[0153] The thickness of the sealing plate is greater than the thickness of the main body of the shell.

Claims

1. A method for manufacturing an energy storage device, the energy storage device comprising an electrode body including a positive electrode and a negative electrode, an electrolyte, and a housing containing the electrode body and the electrolyte. The manufacturing method of the energy storage device is characterized by the following: The housing includes: The housing body comprises a generally rectangular first face having a pair of long sides and a pair of short sides, a pair of second faces extending from the pair of long sides and having an area larger than the first face, a third face opposite the first face, and one or more openings; and One or more sealing plates that seal one or more of the openings. The first surface is equipped with an exhaust valve. The manufacturing method of the energy storage device includes the following steps: In the liquid injection process, the electrolyte is injected into the housing through the liquid injection hole provided in the housing; The charging process involves charging. The housing configuration step involves configuring the housing onto the retaining member; and In the sealing process, the injection hole is sealed by pressing the third surface with a first pressing clamp at a first load value along the direction of the first surface, and pressing the pair of second surfaces with a second pressing clamp at a second load value from both sides, causing the second surfaces to deform in the direction of the inner surface of the housing body. in, In the housing configuration process, The retaining component includes a base portion. The housing is disposed on the retaining member such that the base portion contacts the first surface of the housing body. In the sealing process, The area of ​​the first pressing clamp that faces the third surface of the housing body is made of a material with a lower hardness than the retaining member. The second load value is greater than the first load value.

2. The method for manufacturing the energy storage device according to claim 1, characterized in that, The first pressing clamp includes a first component and a second component with a higher hardness than the first component. The sealing process is performed by having the first component of the first pressing clamp contact the third surface of the housing body.

3. The method for manufacturing the energy storage device according to claim 1 or 2, characterized in that, The first pressing clamp has a stepped portion. The third surface is pressed by the first pressing clamp in such a way that the stepped portion presses against the edge portion where the third surface of the housing intersects with the pair of second surfaces.

4. The method for manufacturing the energy storage device according to claim 1 or 2, characterized in that, The retaining component also has a protrusion. The housing configuration process is performed by engaging the protrusion with the exhaust valve of the housing body.

5. The method for manufacturing the energy storage device according to claim 1 or 2, characterized in that, The second pressing clamp includes a pressing part and a base with a hardness higher than that of the pressing part. The sealing process is performed by having the pressing part of the second pressing clamp contact the second surface.

6. The method for manufacturing the energy storage device according to claim 1 or 2, characterized in that, The retaining member also includes a pair of wall portions extending upward from the base portion. The housing configuration process is performed such that the pair of wall portions of the retaining member contact the pair of second surfaces of the housing body respectively.

7. The method for manufacturing the energy storage device according to claim 1 or 2, characterized in that, The thickness of the sealing plate is greater than the thickness of the main body of the shell.

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