Energy storage device and method for manufacturing an energy storage device

Abstract

To provide an energy storage device in which insulation between the case body and the electrode body is more reliably ensured, and a method for manufacturing an energy storage device that allows the electrode body to be smoothly inserted into the case body. [Solution] The energy storage device 100 according to this disclosure comprises a rectangular tubular case body 12 with both ends in the longitudinal direction open, an electrode body 20, an insulating film 50 disposed between the inner circumferential surface of the case body 12 and the electrode body 20 and covering the electrode body 20, a first lid 14, and a second lid 16. On the first side, the insulating film 50 has a bag portion 54 surrounding a corner portion 20g of the electrode body 20, which is composed of a portion facing a pair of wide surfaces 20b and 20d, a portion facing one of the pair of narrow surfaces 20a and 20c, and a portion facing the first lid 14. The bag portion 54 is composed of a series of integrated films.

Description

Technical Field

[0001] The present disclosure relates to a power storage device and a method for manufacturing the power storage device.

Background Art

[0002] In the battery described in Patent Document 1, at least one of the surface of the enclosure of the insulating film enclosure and the inner surface of the case of the case body has the above-mentioned uneven shape. Therefore, when inserting the power generation element surrounded by the insulating film enclosure into the case body, the frictional resistance generated between the surface of the enclosure and the inner surface of the case can be reduced compared with the case where both the surface of the enclosure and the inner surface of the case are flat surfaces, that is, compared with the conventional case.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present inventor believes that when inserting an electrode body into a case body having a square tubular shape with both sides open in the length direction, even when the square tubular case body and the electrode body are long, the electrode body can be smoothly inserted into the case body, and the insulation between the case body and the electrode body can be more reliably ensured.

Means for Solving the Problems

[0005] The energy storage device according to this disclosure comprises a rectangular tubular case body with openings at both ends in the longitudinal direction, an electrode body housed in the case body, an insulating film disposed between the inner circumferential surface of the case body and the electrode body and covering the electrode body, a first lid attached to the first opening in the longitudinal direction of the case body, and a second lid attached to the second opening in the longitudinal direction of the case body, wherein the case body has a pair of opposing wide surfaces and a pair of opposing narrow surfaces continuous with the pair of wide surfaces, the electrode body is housed in the internal space of the case body and has a laminated structure in which a positive electrode and a negative electrode are laminated between the pair of opposing wide surfaces with a separator in between, and the insulating film has a bag portion on the first side that surrounds a corner portion of the electrode body consisting of a portion facing the pair of wide surfaces, a portion facing one of the pair of narrow surfaces, and a portion facing the first lid, and the bag portion is made up of a series of integrated films.

[0006] In this configuration, the insulating film surrounds the corners of the electrode body with a bag-like portion composed of a series of integrated films. This supports the corners of the electrode body with the insulating film. As a result, displacement of the insulating film due to vibration or other factors is effectively suppressed during use of the energy storage device. Therefore, insulation between the case body and the electrode body can be more reliably ensured. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a perspective view of an energy storage device according to one embodiment. [Figure 2] Figure 2 is a schematic diagram illustrating the internal structure of an energy storage device according to one embodiment. [Figure 3] Figure 3 is a longitudinal cross-sectional view of an energy storage device according to one embodiment. [Figure 4] Figure 4 is a schematic diagram of an insulating film and electrode body according to one embodiment. [Figure 5] Figure 5 is a flowchart of a method for manufacturing an energy storage device according to one embodiment. [Figure 6] Figure 6 is a flowchart illustrating a sub-step in the process of covering an electrode body with an insulating film according to one embodiment. [Figure 7] Figure 7 is a schematic diagram of an insulating film before assembly according to one embodiment. [Figure 8] Figure 8 is a schematic diagram of step S30 according to one embodiment. [Figure 9] Figure 9 is a schematic diagram illustrating the process of inserting an electrode body covered with an insulating film according to one embodiment into the case body. [Figure 10] Figure 10 is a diagram corresponding to Figure 4, relating to the first modified example. [Figure 11] Figure 11 is a diagram corresponding to Figure 7, relating to the first modified example. [Figure 12] Figure 12 is a diagram corresponding to Figure 4, relating to the second modified example. [Figure 13] Figure 13 is a diagram corresponding to Figure 7, relating to the second modified example. [Figure 14] Figure 14 is a diagram corresponding to Figure 4, relating to the third modified example. [Figure 15] Figure 15 is a diagram corresponding to Figure 7, relating to the third modified example. [Modes for carrying out the invention]

[0008] Hereinafter, several embodiments of the technology disclosed herein will be described in detail with reference to the drawings. Matters other than those specifically mentioned herein but necessary for carrying out the technology disclosed herein (for example, the general configuration and manufacturing process of energy storage devices that do not characterize the technology disclosed herein) can be understood as design matters for those skilled in the art based on the prior art. The technology disclosed herein can be carried out based on the content disclosed herein and common technical knowledge in the art. Furthermore, in the following drawings, components and parts that perform the same function are denoted by the same reference numerals.

[0009] Hereinafter, an embodiment of the technology disclosed herein will be described with reference to the drawings. The embodiments described herein are of course not intended to particularly limit the present invention. Each drawing is schematically drawn and does not necessarily reflect the actual object. Also, members and parts having the same function are appropriately given the same reference numerals, and redundant explanations are appropriately omitted. In the following description, the reference numerals L, R, F, Rr, U, and D in the drawings represent left, right, front, back, up, and down. The reference numeral X in the drawings is attached in the long side direction (also referred to as the length direction) of the power storage device. The reference numeral Y in the drawings is attached in the short side direction (also referred to as the thickness direction or the stacking direction of the electrode body) of the power storage device. The reference numeral Z in the drawings is given in the height direction (also referred to as the up-down direction) of the power storage device. However, these are merely directions for convenience of explanation and do not limit the installation form of the power storage device in any way. In this specification, the notation "A to B" indicating a range includes the meanings of "greater than A" and "less than B" as well as the meaning of "A or more and B or less".

[0010] As used herein, the term "power storage device" refers to a device that can be repeatedly charged and discharged. The power storage device includes secondary batteries such as lithium-ion secondary batteries and nickel-metal hydride batteries. The power storage device includes capacitors such as lithium-ion capacitors and electric double layer capacitors.

[0011] FIG. 1 is a perspective view of a power storage device 100 according to an embodiment. FIG. 2 is a schematic diagram for explaining the internal structure of the power storage device 100 according to an embodiment. FIG. 3 is a longitudinal sectional view of the power storage device according to an embodiment. FIG. 4 is a schematic diagram of an insulating film 50 and an electrode body 20 according to an embodiment. In FIG. 4, illustration of the positive electrode tab 22 and the negative electrode tab 24 of the electrode body 20 is omitted. Hereinafter, taking the power storage device 100 shown in FIGS. 1 to 4 as an example, the structure and manufacturing method of the power storage device 100 will be described. Here, a lithium-ion secondary battery is exemplified as the power storage device 100.

[0012] <Power storage device 100> As shown in FIGS. 1 to 3, the power storage device 100 includes a case body 12, an electrode body 20, an insulating film 50, a first lid body 14, and a second lid body 16. Among these, the case body 12, the first lid body 14, and the second lid body 16 are combined to form a case 10 for accommodating the electrode body 20.

[0013] The material of the case 10 may be the same as that conventionally used, and there is no particular limitation. The case 10 is preferably made of metal, and more preferably made of, for example, aluminum, an aluminum alloy, iron, an iron alloy, or the like.

[0014] <Case body 12> As shown in FIGS. 1 to 3, the case body 12 has a rectangular tubular shape with openings on both sides (left and right sides; in other words, the left end portion and the right end portion) in the length direction X of the power storage device 100. In the present embodiment, the case body 12 has a substantially rectangular parallelepiped internal space. In the circumferential direction, the widths of adjacent surfaces of the case body 12 are different, and it has a pair of opposing wide surfaces 12b, 12d and a pair of opposing narrow surfaces 12a, 12c.

[0015] In this embodiment, the case body 12 has a pair of narrow surfaces 12a and 12c, one of which is the bottom surface 12c and the other is the top surface 12a. Although not limited to this, in this embodiment, a gas discharge valve 13 is provided on the bottom surface 12c of the case body 12. The gas discharge valve 13 is configured to rupture when the pressure inside the case 10 exceeds a predetermined value, thereby discharging the gas inside the case 10 to the outside. The predetermined value of the pressure inside the case 10 at which the gas discharge valve 13 ruptures can be adjusted, for example, by changing the size or thickness (depth of the groove) of the gas discharge valve 13. The shape of the gas discharge valve 13 is not particularly limited. The gas discharge valve 13 may be, for example, a linear (vertical or horizontal only) notch. Alternatively, the gas discharge valve 13 may be a conventionally known elliptical valve (with a notch inside) or a circular valve (with a notch inside), etc. Furthermore, the dimensions (length and depth) of the notch are arbitrary and can be determined appropriately, for example, by considering the pressure resistance of the case 10. Also, the location where the gas discharge valve 13 is provided is not particularly limited and may be provided in a place other than the bottom surface 12c of the case body 12.

[0016] As shown in Figure 3, openings 12h1 and 12h2 are formed at both ends (ends 12e1 and 12e2) of the case body 12 in the long side direction X. Opening 12h1 is formed at the first side (left side) end 12e1 of the case body 12. Opening 12h2 is formed at the second side (right side) end 12e2 of the case body 12. The openings 12h1 and 12h2 are substantially rectangular in shape. In this embodiment, the case body 12 is sufficiently longer in the long side direction X than in the short side direction Y and the height direction Z in the circumferential direction. The electrode body 20 is inserted through one of the openings 12h1 and 12h2 (in this embodiment, the left opening 12h1) while covered with the insulating film 50. Thus, the case body 12 is a rectangular tubular member with openings at both ends in the length direction, and has a pair of openings 12h1 and 12h2 at both ends in the length direction.

[0017] <First lid 14, second lid 16> The first cover 14 is a component that is attached to the first opening 12h1 in the longitudinal direction of the case body 12. The second cover 16 is a component that is attached to the second opening 12h2 in the longitudinal direction of the case body 12. The first cover 14 and the second cover 16 are joined to the peripheral edges of the openings 12h1 and 12h2 of the case body 12. The first cover 14 and the second cover 16 are substantially rectangular plate-shaped components. The area of ​​the first cover 14 and the second cover 16 is smaller than the wide surfaces 12b and 12d. The first cover 14 and the second cover 16 are joined to the peripheral edges of the openings 12h1 and 12h2 after the electrode body 20 and the insulating film 50 have been housed in the case body 12. The first cover 14 and the second cover 16, joined to the case body 12, face each other in the long side direction X. In this embodiment, the second lid 16 is provided with an injection hole 15. The injection hole 15 is sealed with a sealing member 15a. The injection hole 15 may also be provided in the first lid 14.

[0018] Electrode terminals may be attached to the first cover 14 and the second cover 16, respectively. In this embodiment, a negative electrode terminal 40 is attached to the first cover 14, and a positive electrode terminal 30 is attached to the second cover 16. The positive electrode terminal 30 is electrically connected to the positive electrode of the electrode body 20 via a positive electrode current collector terminal 32. The negative electrode terminal 40 is electrically connected to the negative electrode of the electrode body 20 via a negative electrode current collector terminal 42. The positive electrode terminal 30 is preferably made of metal, and more preferably of aluminum or an aluminum alloy. The negative electrode terminal 40 is preferably made of metal, and more preferably of copper or a copper alloy. The positive electrode terminal 30 and the negative electrode terminal 40 are insulated from the first cover 14 and the second cover 16, respectively, by an insulating member (not shown). The positive electrode terminal 30 and the negative electrode terminal 40 are each exposed on the outer surface of the case 10. The positive terminal 30 and the negative terminal 40 are each connected to a conductive member such as a busbar outside the case 10.

[0019] <Electrode body 20> The electrode body 20 is housed in the internal space of the case 10 (case body 12). As shown in Figure 2, the electrode body 20 is placed inside the case 10 covered with an insulating film 50, which will be described later. In this embodiment, one electrode body 20 is housed inside one case 10. However, the number of electrode bodies 20 housed inside one case 10 is not particularly limited, and in other embodiments, there may be multiple (two or more).

[0020] The electrode body 20 has a laminated structure in which a positive electrode and a negative electrode are stacked between a pair of opposing wide surfaces 12b and 12d inside the case body 12 with a separator in between. Here, the electrode body 20 is a wound electrode body. Specifically, the electrode body 20 is formed by winding a laminate, which is made by stacking a strip-shaped positive electrode and a strip-shaped negative electrode with a strip-shaped separator in between, in the longitudinal direction around a winding axis. However, it is not limited to this, and the electrode body 20 may be a so-called laminated electrode body in which a rectangular positive electrode and a rectangular negative electrode are stacked with a separator in between. Alternatively, the electrode body 20 may be a laminated electrode body in which a square-shaped positive electrode and a square-shaped negative electrode are stacked in a state insulated by a zigzag-folded separator. The individual components constituting the electrode body 20 (positive electrode, negative electrode, separator, etc.) are not particularly limited.

[0021] The electrode body 20 has a flattened shape in this case. The electrode body 20 has a pair of mutually opposing wide surfaces 20b and 20d, a pair of mutually opposing narrow surfaces 20a and 20c connecting the long sides of the wide surfaces 20b and 20d, and lid-facing surfaces 20e and 20f. The wide surface 20b is one side of the electrode body in the stacking direction Y and is the side facing the wide surface 12b of the case body 12. The wide surface 20d is the other side of the electrode body in the stacking direction Y and is the side facing the wide surface 12d of the case body 12. The narrow surface 20a is the side facing the top surface 12a of the case body 12. The narrow surface 20c is the side facing the bottom surface 12c of the case body 12. The wide surfaces 20b and 20d and the narrow surfaces 20a and 20c constitute the circumferential surface of the electrode body 20. The lid-facing surface 20e is the surface facing the first lid 14. The lid-facing surface 20f is the surface facing the second lid 16. In this embodiment, the lid-facing surfaces 20e and 20f expose the laminated structure of multiple positive electrodes and multiple negative electrodes along the lamination direction (thickness direction Y).

[0022] In this embodiment, four corners 20g are formed on the first side (left side) of the electrode body 20. Of the four corners 20g, the upper corner 20g is composed of the wide surface 20b, 20d, the narrow surface 20a, and the lid-facing surface 20e of the electrode body 20. Of the four corners 20g, the lower corner 20g is composed of the wide surface 20b, 20d, the narrow surface 20c, and the lid-facing surface 20e of the electrode body 20.

[0023] As shown in Figure 4, the electrode body 20 is substantially rectangular in shape. However, it is not limited to this, and for example, the narrow surfaces 20a and 20c may have curved portions. The electrode body 20 may be housed inside the case 10 with the winding axis oriented along the vertical direction Z. In other words, the electrode body 20 may be a so-called vertical winding type.

[0024] The positive electrode comprises a positive electrode current collector foil and a positive electrode active material layer formed on at least one surface of the positive electrode current collector foil. The positive electrode current collector foil is made of a metal material having a predetermined conductivity. As the positive electrode current collector foil, a metal foil can be used, for example, aluminum, an aluminum alloy, etc. The positive electrode active material layer is a layer containing a positive electrode active material. The positive electrode active material is a material that can reversibly absorb and release charge carriers in relation to the negative electrode active material described later. The positive electrode active material is not particularly limited. As the positive electrode active material, for example, lithium transition metal composite oxides such as lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, lithium nickel manganese composite oxide, and lithium nickel cobalt composite oxide can be used. The positive electrode active material layer may contain additives such as binders and conductive materials.

[0025] The negative electrode comprises a negative electrode current collector foil and a negative electrode active material layer formed on at least one surface of the negative electrode current collector foil. The negative electrode current collector foil is made of a metal material having a predetermined conductivity. As the negative electrode current collector foil, a metal foil can be used, for example, copper, copper alloys, etc. The negative electrode active material layer is a layer containing negative electrode active material. The negative electrode active material is a material that can reversibly absorb and release charge carriers in relation to the positive electrode active material. The negative electrode active material is not particularly limited. As the negative electrode active material, for example, carbon materials, silicon-based materials, and mixed oxides thereof can be used. As carbon materials, for example, graphite, hard carbon, soft carbon, amorphous carbon, etc. can be used. As silicon-based materials, silicon, silicon oxide, etc. can be used. The negative electrode active material layer may contain additives such as binders, conductive materials, and thickeners.

[0026] A separator is interposed between the positive and negative electrodes. The separator has multiple fine through-holes that allow charge carriers to pass through. The separator may comprise a substrate and a heat-resistant layer (HRL) formed on the surface of the substrate. A porous resin membrane is preferably used as the substrate. For example, a porous sheet (film) made of a resin such as polyethylene (PE), polypropylene (PP), or polyamide may be used as the substrate. The substrate may have a single-layer structure or a laminated structure of two or more layers. The heat-resistant layer may contain ceramic particles and a binder. The separator may also include an adhesive layer. The adhesive layer is a layer with excellent adhesion to the electrode plates (positive and negative electrodes). The adhesive layer may be formed on the surface of the separator. A resin material may be used as the adhesive layer, for example, a fluororesin or an acrylic resin may be used. The adhesive layer may also contain inorganic fillers.

[0027] The electrode body 20 comprises a positive electrode tab 22 and a negative electrode tab 24, extending in opposite directions. The positive electrode tab 22 is the portion extending from the second side (right side) end of the electrode body 20 toward the second side. The positive electrode tab 22 is the portion where the positive electrode active material layer is not formed and the positive electrode current collector foil is exposed. The positive electrode tab 22 is composed of multiple layers of positive electrode current collector foil that protrude toward the second side. The negative electrode tab 24 is the portion extending from the first side (left side) end of the electrode body 20 toward the first side. The negative electrode tab 24 is the portion where the negative electrode active material layer is not formed and the negative electrode current collector foil is exposed. The negative electrode tab 24 is composed of multiple layers of negative electrode current collector foil that protrude toward the first side.

[0028] The insulating film 50 is positioned between the inner circumferential surface of the case body 12 and the electrode body 20. As shown in Figure 4, the insulating film 50 covers the periphery of the electrode body 20. The insulating film 50, also called an electrode body holder, is an insulating member that covers the electrode body 20 and insulates the electrode body 20 from the case 10 (case body 12).

[0029] The material of the insulating film 50 is not particularly limited, but it is preferably made of resin, for example, olefin resins such as polyethylene (PE), polypropylene (PP / OPP), and polymethylpentene (PMP / TPX®), polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), fluororesins such as acrylic resin (PMMA), polyimide (PI), polyphenylene ether (PPE), triacetate (TAC), polyphenylene sulfide resin (PPS), polycarbonate (PC), nylon, and polytetrafluoroethylene (PTFE).

[0030] The thickness of the insulating film 50 is not particularly limited, but from the viewpoint of providing sufficient mechanical strength, it may be, for example, 50 μm or more, and preferably 100 μm or more. From the viewpoint of the capacity inside the case 10, the thickness of the insulating film 50 may be, for example, approximately 250 μm or less, and preferably 200 μm or less.

[0031] Incidentally, for a rectangular tubular case body 12 with openings on both sides in the longitudinal direction, the electrode body 20 is inserted into the case body 12 from the first opening 12h1 while covered with an insulating film 50. The electrode body 20 has a laminated structure in which a positive electrode and a negative electrode are stacked between a pair of opposing wide surfaces with a separator in between. Therefore, the gap between the electrode body 20 and the inner surface of the case body 12 is small in the plane perpendicular to the direction in which it is inserted into the case body 12. Furthermore, the long side direction X of the case body 12 may be sufficiently longer than the short side direction Y in the circumferential direction and the height direction Z, and the electrode body 20 may also be long in the long side direction X of the case body 12. In such a case, when the electrode body 20 is inserted into the case body 12 from the first opening 12h1 while covered with an insulating film 50, if the insulating film 50 or the electrode body 20 gets caught near the opening 12h1 of the case body 12, the electrode body 20 cannot be smoothly accommodated in the case body 12. Furthermore, when using the energy storage device 100, vibrations or other factors may cause the insulating film 50 to shift away from the electrode body 20, which could impair its insulating properties.

[0032] The insulating film 50 according to this embodiment is a bag-shaped member having a circumferential portion 52 and a bag portion 54. The circumferential portion 52 covers the parts of the electrode body 20 that face the wide surfaces 12b and 12d of the case body 12 (wide surfaces 20b and 20d) and the parts that face the narrow surfaces (bottom surface 12c and top surface 12a) (narrow surfaces 20a and 20c). The circumferential portion 52 covers the periphery of the electrode body 20 along a direction perpendicular to the long side direction X. As shown in Figure 3, the circumferential portion 52 faces the inner surface of the case body 12.

[0033] In this embodiment, the insulating film 50 has a circumferential surface portion 52 comprising a first surface 52a, a second surface 52b, a third surface 52c, a fourth surface 52d, and a fifth surface 52e. The first surface 52a is the surface that follows the narrow surface 20a of the electrode body 20 and is the portion that faces the top surface 12a of the case body 12. The second surface 52b is the surface that follows the wide surface 20b of the electrode body 20 and is the portion that faces the wide surface 12b of the case body 12. The third surface 52c is the surface that follows the narrow surface 20c of the electrode body 20 and is the portion that faces the bottom surface 12c of the case body 12. The fourth surface 52d is the surface that follows the wide surface 20d of the electrode body 20 and is the portion that faces the wide surface 12d of the case body 12. The dimensions of the first surface 52a to the fourth surface 52d can be set according to the dimensions of the electrode body 20. The areas of the second surface 52b and the fourth surface 52d are larger than those of the first surface 52a and the third surface 52c. The fifth surface 52e is a surface that overlaps the outside of the first surface 52a and is the part that faces the top surface 12a of the case body 12. The area of ​​the fifth surface 52e is smaller than the area of ​​the first surface 52a.

[0034] The bag portion 54 surrounds the corner portion 20g of the electrode body 20. As shown in Figure 4, here, two bag portions 54 surround two corner portions 20g of the electrode body 20, respectively. In this embodiment, the bag portion 54 is formed on the first side and faces the first lid 14 inside the case 10. The bag portion 54 may be provided only on the first side (one side in the longitudinal direction), or on both sides (both sides in the longitudinal direction) of the first and second sides. The bag portion 54 is composed of a series of integrated films. With this configuration, the corner portion 20g of the electrode body 20 is supported by the insulating film 50 by the bag portion 54. This effectively suppresses displacement of the insulating film 50 due to vibration, etc., when the energy storage device 100 is in use. Therefore, the insulation between the case body 12 and the electrode body 20 can be more reliably ensured.

[0035] In this embodiment, the bag portion 54 is heat-sealed and integrated into a bag shape. This configuration makes the bag portion 54 more robust. As a result, displacement of the insulating film 50 due to vibration or the like is more effectively suppressed when the energy storage device 100 is in use. Therefore, the insulation between the case body 12 and the electrode body 20 can be more reliably ensured.

[0036] In this embodiment, the insulating film 50 is provided with a gripping portion 56 at the end of the second side (in this case, the right side) of the electrode body 20 when viewed in the longitudinal direction X. More specifically, in the insulating film 50 according to this embodiment, a second notch portion N2 is formed on the second side of the first surface 52a, second surface 52b, third surface 52c, and fourth surface 52d. The second notch portion N2 is formed parallel to the long side direction X. As a result, there are two gripping portions 56 each (a total of four) on the upper and lower parts of the second side of the second surface 52b and fourth surface 52d of the insulating film 50.

[0037] <Manufacturing method for energy storage devices> Next, a method for manufacturing the energy storage device 100 will be described. Figure 5 is a flowchart of a method for manufacturing an energy storage device according to one embodiment. As shown in Figure 5, the method for manufacturing the energy storage device includes a step S10 for preparing the case body, a step S20 for preparing the electrode body, a step S30 for covering the electrode body with an insulating film, and a step S40 for inserting the electrode body covered with the insulating film into the case body. The manufacturing method disclosed herein may further include other steps at any stage.

[0038] (Step S10: Preparing the case itself) In step S10 (hereinafter also simply referred to as "step S10"), a rectangular tubular case body 12 with openings on both sides in the longitudinal direction X is prepared. The case body 12 may be purchased commercially or manufactured by conventionally known methods. The case body 12 can be formed, for example, by bending a single metal plate into a rectangular tubular shape and joining the joint (for example, by welding). The case body 12 may also be formed by joining multiple metal plates.

[0039] (Step S20: Preparation of electrode bodies) In step S20 (hereinafter also simply referred to as "step S20"), the electrode body 20 to be housed in the case body is prepared. The electrode body 20 may be purchased commercially or manufactured using conventionally known methods.

[0040] (Step S30: Covering the electrode body with an insulating film) In step S30, the electrode body 20 prepared in the electrode body preparation step is covered with an insulating film 50. Figure 6 is a flowchart illustrating a sub-step of step S30 according to one embodiment. Step S30, in which the electrode body is covered with an insulating film, may include, for example, an insulating film preparation step S32, an insulating film folding step S34, and a bag portion formation step S36 as sub-steps, as shown in Figure 6. A detailed explanation follows below.

[0041] (Insulating film preparation process S32) In the insulating film preparation step S32, first, an insulating film 50 is prepared, cut to a shape and size that conforms to the outer shape of the electrode body 20. The material and thickness of the insulating film 50 to be prepared have already been described above, so a redundant explanation is omitted here. Figure 7 is a schematic diagram of the insulating film 50 before assembly according to one embodiment. In Figure 7, the first bent portion 50a and the second bent portion 50b are shown by dashed lines. Figure 8 is a schematic diagram of step S30 according to one embodiment. In Figure 8, the positive electrode tab 22 and negative electrode tab 24 of the electrode body 20 are not shown. The dimensions of the insulating film 50 can be determined according to the dimensions of the electrode body 20. The width of the insulating film 50 (dimension along the long side direction X) is at least greater than the dimension along the long side direction X of the electrode body 20, excluding the positive electrode tab 22 and negative electrode tab 24. The length of the insulating film 50 (dimension along the direction perpendicular to the long side direction X) is longer than the circumference of the electrode body 20. Here, "the length of the circumference of the electrode body 20" refers to the circumference along the direction perpendicular to the longer side direction X.

[0042] In this embodiment, the insulating film 50 has four first bends 50a along the long side direction X of the electrode body 20, and the first surface 52a to the fifth surface 52e are set with the first bends 50a as the boundary. The first bends 50a may be processed to make the insulating film 50 easier to bend (for example, groove processing or perforation processing). The first bends 50a may be set according to the dimensions of the electrode body 20.

[0043] As shown in Figure 7, the insulating film 50 according to this embodiment has seven first notches N1 formed therein. The first notches N1 are formed parallel to the long side direction X of the insulating film 50. More specifically, two first notches N1 are formed at the first side end of the surfaces where the second surface 52b and the fourth surface 52d of the insulating film 50 are set (a total of four notches). The remaining three first notches N1 are formed to extend from the first bend portion 50a along the long side direction X toward the first side. Furthermore, as shown in Figure 7, in the insulating film 50 according to this embodiment, on the surfaces where the first surface 52a, the second surface 52b, the third surface 52c, and the fourth surface 52d are set, the second bend portion 50b is set from the base of the first notch N1 in a direction perpendicular to the first bend portion 50a (in other words, perpendicular to the long side direction X). Then, with the second bend portion 50b as the boundary, a total of six pocket-forming portions 54a, 54b, 54c, and 54d are set on the first side of the insulating film 50. The second bend portion 50b may be processed to make the insulating film 50 easier to bend (for example, groove processing or perforation processing).

[0044] The depth of the first cut portion N1 can be adjusted as appropriate depending on the thickness of the electrode body 20. Preferably, the depth of the first cut portion N1 is such that when the second folded portion 50b of the insulating film 50 is folded, multiple (two or more) insulating films 50 overlap, that is, a depth that allows a bag portion 54 to be formed. Depth D of the first cut portion N1 N1 (mm) is determined from the viewpoint of facilitating the bag formation process S36 (facilitating the joining of the overlapping portions of the bag formation portions 54a, 54b, and 54d), for example, when the width of the third surface 52c in the direction perpendicular to the first folded portion 50a of the insulating film 50 (in other words, the direction perpendicular to the long side direction X) is W (mm) (see Figure 7), then W / 3 ≤ D N1 It is preferable that it be within the range of ≤W.

[0045] In the insulating film 50 according to this embodiment, a second notch N2 is formed on the second side of the first surface 52a, second surface 52b, third surface 52c, and fourth surface 52d. The depth of the second notch N2 may be the same as or different from the depth of the first notch N1, and is not particularly limited as long as it can grip the insulating film 50. Depth D of the second notch N2 N2 (mm) is, for example, when the width of the third surface 52c in the direction perpendicular to the first folded portion 50a of the insulating film 50 is W (mm) (see Figure 7), then W / 2 + 5 ≤ D N2 It is preferable that the value is within the range of ≤W / 1.41+15.

[0046] (Insulating film folding process S34) In the insulating film bending process S34, first, the electrode body 20 is placed on the insulating film 50 as shown in Figure 8(a). Here, the third surface 52c of the insulating film 50 and one narrow surface 20c of the electrode body 20 are in contact, and the electrode body 20 is positioned so that one narrow surface 20c of the electrode body 20 does not straddle the first bent portion 50a and the second bent portion 50b.

[0047] Next, as shown in Figure 8(b), the insulating film 50 is folded along the first folded portion 50a. This folds the insulating film 50 so that the first surface 52a to the fourth surface 52d are aligned with the electrode body 20. Subsequently, the fifth surface 52e is superimposed on the first surface 52a and joined to the first surface 52a. This joining method may be heat welding, adhesive, or tape. From the viewpoint of joining strength, heat welding is preferred. As a result, the insulating film 50 is formed into a cylindrical shape, and the peripheral surfaces of the electrode body 20 (wide surfaces 20b, 20d, narrow surfaces 20a, 20c) are covered by the insulating film 50.

[0048] (Bag forming step S36) In the bag portion formation process S36, a bag portion 54 is formed from the insulating film 50. In this embodiment, as shown in Figure 8(c), the insulating film 50 is folded along the second folded portion 50b. At this time, the three bag portion forming portions 54b, 54c, and 54d overlap on the lower side of the electrode body 20 when viewed in the vertical direction Z of the electrode body 20. Then, the overlapping portions of the bag portion forming portions 54b, 54c, and 54d are joined together. As a result, on the lower side of the first side of the electrode body 20, the two corners 20g of the electrode body 20 are each surrounded by the insulating film 50, and a bag portion 54 is formed. On the other hand, the three bag portion forming portions 54a, 54b, and 54d overlap on the upper side of the electrode body 20 when viewed in the vertical direction Z of the electrode body 20. Then, the overlapping portions of the bag portion forming portions 54a, 54b, and 54d are joined together. As a result, on the upper side of the first side of the electrode body 20, the two corners 20g of the electrode body 20 are each surrounded by the insulating film 50, and a bag portion 54 is formed. In this way, a bag-shaped insulating film 50 is formed, and the electrode body 20 is covered by the insulating film 50. The overlapping portion may be joined by heat welding, or by adhesive or tape. From the viewpoint of joining strength, it is preferable to form the bag portion 54 by joining by heat welding.

[0049] (Step S40: Inserting the electrode body covered with insulating film into the case body) In step S40 (hereinafter also simply referred to as "step S40"), in which the electrode body covered with an insulating film is inserted into the case body, the electrode body 20 and the insulating film 50 are inserted into the case body 12 while the electrode body 20 is housed (covered) in the insulating film 50. At this time, the tip end (second side in this embodiment) of the electrode body 20 is inserted into one of the openings (opening 12h1 in this embodiment) of the case body 12. With this configuration, the electrode body 20 is inserted while being supported by the bag portion 54 of the insulating film 50. This prevents the insulating film 50 and the electrode body 20 from getting caught near the opening 12h1 of the case body 12. Therefore, the electrode body 20 can be smoothly housed in the case body 12.

[0050] In this specification, "tip of the electrode body" refers to the end of the electrode body 20 opposite to the end where the corner 20g of the electrode body 20 is enclosed by the bag portion 54, when viewed in the longitudinal direction X of the electrode body 20. Figure 9 is a schematic diagram showing the process of inserting an electrode body covered with an insulating film according to one embodiment into the case body. In Figure 9, the direction in which the electrode body 20 and the insulating film 50 are inserted into the case body 12 is indicated by a white arrow.

[0051] Although not limited thereto, step S40 can be carried out, for example, by the following method. First, a pressing block 500, which is a member for pressing the electrode body 20, is prepared. As shown in Figure 9, the pressing block 500 according to this embodiment is a so-called U-shaped member comprising a base portion 510 and a pressing portion 520. The base portion 510 extends in the vertical direction Z, and the pressing portion 520 extends to the second side from the upper end and lower end of the base portion 510, respectively. The shape of the pressing block 500 is not limited to the above, and it is sufficient that the pressing portion 520 is formed to press the bag portion 54 of the insulating film 50. The size of the pressing block 500 is not particularly limited and can be appropriately changed depending on the size of the electrode body 20, but it is preferable that the pressing block 500 is sized so that it can be inserted into the case body 12. In other words, it is preferable that the pressing block 500 is smaller than the opening of the case body 12.

[0052] Next, the pressing portion 520 of the pressing block 500 prepared above is positioned so that it contacts the pocket portion 54 of the insulating film 50. Then, the pressing portion 520 of the pressing block 500 pushes the pocket portion 54 of the insulating film 50 toward the tip (right side) of the electrode body 20, thereby pushing the electrode body 20 from the first opening 12h1 toward the second side (in the direction of the white arrow in Figure 9). As a result, the second side of the electrode body 20 is inserted into the case body 12. With this configuration, the electrode body 20 is inserted while more reliably supporting the pocket portion 54 of the insulating film 50. Therefore, the displacement of the insulating film 50 during insertion of the electrode body 20 is suitably suppressed, and the electrode body 20 can be inserted into the case body 12 more smoothly.

[0053] As shown in Figure 9, in this embodiment, the narrow side 12c of the case body 12 and the third side 52c of the insulating film 50 are positioned facing downwards, and the electrode body 20 is inserted. However, it is sufficient that the electrode body 20 can be pushed from the opening 12h1 on the first side to the second side, and the orientation in which the case body 12 and the insulating film 50 (electrode body 20) are positioned is not limited to this.

[0054] Although not limited thereto, in this embodiment, the electrode body 20 is further inserted using a chuck 600. As shown in Figure 9, the chuck 600 used in this embodiment has a jaw portion 610 and an arm portion 620. The number of chucks used in this step is not particularly limited; one chuck may be used, or multiple (two or more) chucks may be used. In this embodiment, two chucks 600 are used. The shape of the chuck 600 is not particularly limited, but it is preferable that the length of the arm portion 620 is longer than the length X of the case body 12.

[0055] First, as shown in Figure 9, the arm portion 620 is passed from the second opening 12h2 of the case body 12 to the first opening 12h1. This causes the claw portion 610 of the chuck 600 to protrude from the first opening 12h1. Next, the insulating film 50 is grasped by the claw portion 610. In this embodiment, the claw portion 610 grasps the gripping portion 56. As shown in Figure 9, here, the two gripping portions 56 extending from the second surface 52b and the fourth surface 52d of the insulating film 50 are grasped at once. However, multiple chucks 600 may be used to grasp the gripping portions 56 of the insulating film 50 one by one. Then, while still grasping the insulating film 50 (in this case, the gripping portion 56), the claw portion 610 is moved from the first opening 12h1 to the second side (in the direction of the white arrow). This pulls the insulating film 50, and the second side of the electrode body 20 is inserted into the case body 12.

[0056] When the electrode body 20 is inserted to the center of the case body 12, the positive electrode tab 22 protrudes outward from the second opening 12h2 of the case body 12. The negative electrode tab 24 protrudes outward from the first opening 12h1 of the case body 12.

[0057] The means used in step S40 are not limited to those described above. For example, step S40 may be performed using either the push block 500 or the chuck 600.

[0058] In the embodiment described above, the bag portion 54 is formed by heat-sealing the insulating film 50 to the bag portion 54. This configuration improves the strength of the bag portion 54. As a result, in step S40, in which the electrode body covered with the insulating film is inserted into the case body, the bag portion 54 can more reliably support the corner portion 20g of the electrode body 20. Therefore, the electrode body 20 and the insulating film 50 can be more easily housed in the case body 12.

[0059] In the embodiment described above, the insulating film 50 has a gripping portion 56 that extends from the second end of the electrode body 20 toward the second lid 16 when viewed in the longitudinal direction X. With this configuration, the electrode body 20 and the insulating film 50 are housed in the case body 12 by gripping the gripping portion 56 of the insulating film 50 and pulling it. This allows the electrode body 20 to be smoothly inserted into the case body 12, and also prevents the electrode body 20 from bending even if the insulating film 50 or the electrode body 20 gets caught near the opening 12h1 of the case body 12. Therefore, the electrode body 20 and the insulating film 50 can be housed in the case body 12 more easily.

[0060] After housing the insulating film 50 and the electrode body 20 in the case body 12, the openings 12h1 and 12h2 of the case body 12 are closed with the first cover 14 and the second cover 16. A positive electrode tab 22 protruding from the second side opening 12h2 of the case body 12 is connected to a positive electrode current collector terminal 32. A negative electrode tab 24 protruding from the first side opening 12h1 of the case body 12 is connected to a negative electrode current collector terminal 42. The positive electrode current collector terminal 32 is connected to the positive electrode terminal 30 of the second cover 16, and the negative electrode current collector terminal 42 is connected to the negative electrode terminal 40 of the first cover 14. Then, while the positive electrode tab 22 and the negative electrode tab 24 are bent, the first cover 14 and the second cover 16 are welded to the periphery of the openings 12h1 and 12h2. As a result, the openings 12h1 and 12h2 of the case body 12 are closed by the first lid 14 and the second lid 16.

[0061] Here, the first cover 14 on the rear side in the insertion direction when the electrode body 20 is inserted into the case body 12 is preferably connected to the electrode tab on the rear side in the insertion direction (negative electrode tab 24 in this embodiment) before the electrode body 20 is housed in the case body 12. Then, when the electrode body 20 is inserted into the case body 12, the first cover 14 is preferably positioned to close the opening 12h1 of the case body 12. The second cover 16 is preferably connected to the electrode tab on the front side in the insertion direction (positive electrode tab 22 in this embodiment) after the electrode body 20 has been housed in the case body 12.

[0062] After sealing case 10, electrolyte is injected through injection hole 15. After the electrolyte is injected, injection hole 15 is sealed by sealing member 15a. After injection, initial charging, aging, and other processes are performed to manufacture the energy storage device 100.

[0063] 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 a mixture of EC, EMC, and DMC in amounts ranging from 1% to 99% each, with a total ratio of 100%. The supporting salt is, for example, a fluorine-containing lithium salt. The fluorine-containing lithium salt preferably includes lithium hexafluorophosphate (LiPF6), lithium bis(fluorosulfonyl)imide (F2LiNO4S2) called LiFSI, or a mixture thereof. The concentration of the supporting salt is preferably 0.6 to 1.8 mol per liter of non-aqueous solvent.

[0064] The energy storage device 100 can be used for various applications, but it is particularly suitable as a power source (driving power supply) for motors mounted on vehicles such as passenger cars and trucks. The type of vehicle is not particularly limited, but examples include plug-in hybrid electric vehicles (PHEVs), hybrid electric vehicles (HEVs), and battery electric vehicles (BEVs).

[0065] Although embodiments relating to this disclosure have been described above, these embodiments are merely examples. The present invention can be implemented in various other forms. This disclosure can be implemented based on the contents disclosed herein and common technical knowledge in the art. The technologies described in the claims include various modifications and changes to the embodiments illustrated above. For example, it is possible to replace parts of the above embodiments with other variations, and it is also possible to add other variations to the above embodiments. Furthermore, if a technical feature is not described as essential, it may be deleted as appropriate.

[0066] For example, in the above-described embodiment, the bag portion 54 was formed at the lower part of the electrode body 20 by joining the overlapping portions of the three bag portion forming portions 54b, 54c, and 54d. Also, in the above-described embodiment, the bag portion 54 was formed at the upper part of the electrode body 20 by joining the overlapping portions of the three bag portion forming portions 54a, 54b, and 54d. However, the embodiment is not limited to these.

[0067] (First variation) Figure 10 is a diagram corresponding to Figure 4 relating to the first modified example. Figure 11 is a diagram corresponding to Figure 7 relating to the first modified example. In the first modified example, an insulating film 150 is provided instead of the insulating film 50. The insulating film 150 comprises a first surface 152a, a second surface 152b, a third surface 152c, a fourth surface 152d, and a fifth surface 152e.

[0068] As shown in Figure 10, in this modified example, the insulating film 150 extends from the end of the bag portion 154 toward the first side on the first surface 152a and the third surface 152c. Other than this, it may be the same as the insulating film 50. Furthermore, the configuration of the energy storage device other than the insulating film 150 may be the same as in the embodiment described above.

[0069] As shown in Figure 11, the insulating film 150 according to this modified example does not have a second folded portion 150b on the surface where the first surface 152a and the third surface 152c are set. That is, in the first modified example, in the bag portion forming step S36, the bag portion 154 is formed by joining the overlapping portions of the two bag portion forming portions 154b and 154d. Even in this case, the corner portion 20g of the electrode body 20 can be surrounded at the upper and lower parts of the first side of the electrode body 20.

[0070] When forming the bag portion 154 with two bag portion forming portions 154b and 154d, the depth D of the first cut portion N1 N1‘ (mm) is calculated from the viewpoint of facilitating the bag formation process S36, for example, when the width of the third surface 152c in the direction perpendicular to the first folded portion 50a of the insulating film 150 is W (mm) (see Figure 11), then W / 2 <D N1’ It is preferable that it be within the range of ≤W.

[0071] For example, in the embodiment described above, a second notch N2 was formed on the second side of the first surface 52a, second surface 52b, third surface 52c, and fourth surface 52d of the insulating film 50. As a result, gripping portions 56 were set on the upper and lower parts of the second side of the second surface 52b and fourth surface 52d of the insulating film 50. However, the embodiment is not limited to this.

[0072] (Second variation) Figure 12 is a diagram corresponding to Figure 4 relating to the second modified example. Figure 13 is a diagram corresponding to Figure 7 relating to the second modified example. In the second modified example, an insulating film 250 is provided instead of the insulating film 50. The insulating film 250 comprises a first surface 252a, a second surface 252b, a third surface 252c, a fourth surface 252d, and a fifth surface 252e.

[0073] As shown in Figures 12 and 13, the insulating film 250 according to this modified example has through holes as gripping portions 256 on the second surface 252b and the fourth surface 252d. The shape of these through holes is not particularly limited, and various shapes such as circular, square, semicircular, and triangular can be used. The size of the through holes is not particularly limited, but from the viewpoint of ensuring the strength of the insulating film 50, it is preferably 15 mm or less, and more preferably 12 mm or less. The size of the through holes is not particularly limited, but it is preferably 4 mm or more, and more preferably 7 mm or more. The number of through holes may be one or multiple (two or more). In addition, in the second modified example, the insulating film 250 does not have a second notch N2.

[0074] Although not limited thereto, in a second modification, for example, step S40 can be carried out using a chuck 600. The chuck 600 may be the same as in the embodiment described above. The jaw portion 610 of the chuck 600 is made to grip the gripping portion 256. This allows the chuck 600 to more preferably grip and pull the insulating film 250. In other words, the electrode body 20 and the insulating film 250 can be more preferably inserted into the case body 12.

[0075] Although not limited to this, as shown in Figures 12 and 13, in the second modified example, the through-holes (gripping portions 256) are provided symmetrically with respect to the center line (not shown) in the vertical Z direction. With this configuration, when pulling the insulating film 250, the tensile force is more easily applied evenly to the insulating film 250. This allows the electrode body 20 and the insulating film 250 to be inserted smoothly into the case body 12.

[0076] (Third variation) Furthermore, in the second modified example described above, the through-holes (gripping portion 256) were provided on the second surface 252b and the fourth surface 252d of the insulating film 250. However, the location where the gripping portion 256 is provided is not limited to these. Figure 14 is a diagram corresponding to Figure 4 relating to the third modified example. Figure 15 is a diagram corresponding to Figure 7 relating to the third modified example. In the third modified example, an insulating film 350 is provided instead of the insulating film 50. The insulating film 350 comprises a first surface 352a, a second surface 352b, a third surface 352c, a fourth surface 352d, and a fifth surface 352e.

[0077] As shown in Figures 14 and 15, the insulating film 350 according to this modified example has one gripping portion 356 as a through hole on each of the surfaces where the first surface 351a and the third surface 351c are set. That is, the arrangement of the gripping portions 356 can be appropriately changed by means of gripping the insulating film 350 during step S40. Similarly, the shape of the gripping portions can be appropriately changed. This allows the electrode body 20 and the insulating film 250 to be smoothly inserted into the case body 12.

[0078] As described above, specific embodiments of the technology disclosed herein include those described in the following sections.

[0079] [Section 1] A rectangular tubular case body with openings at both ends in the longitudinal direction, The electrode body housed in the above-mentioned case, An insulating film is placed between the inner circumferential surface of the case body and the electrode body, and covers the electrode body. A first lid is attached to the first opening in the longitudinal direction of the case body, A second lid is attached to the second opening in the longitudinal direction of the case body, Equipped with, The case body mentioned above is A pair of opposing wide surfaces, A pair of opposing narrow surfaces that are continuous with the pair of wide surfaces mentioned above It has, The electrode body described above is The internal space of the above-mentioned case body is housed, The device has a laminated structure in which a positive electrode and a negative electrode are stacked between the pair of opposing wide surfaces with a separator in between. The above insulating film is On the first side described above, the electrode body is provided with a bag portion that surrounds the corner portion, which is composed of a portion facing the pair of wide surfaces, a portion facing one of the pair of narrow surfaces, and a portion facing the first lid. The bag portion described above is composed of a series of integrated films. Energy storage device. [Section 2] The above-mentioned bag portion is formed by heat-sealing the above-mentioned film to create a single, integrated bag-like structure. The energy storage device described in item 1. [Section 3] The insulating film further includes a gripping portion at the second end of the electrode body. A power storage device as described in item 1 or 2. [Section 4] The above insulating film has through holes as gripping portions. The energy storage device described in item 3. [Section 5] Multiple through holes are provided symmetrically across the height of the case body. The energy storage device described in item 4. [Section 6] The electrode body described above is A first electrode tab extends toward the first side in the longitudinal direction of the case body and is connected to an electrode terminal provided on the first lid, A second electrode tab extends toward the second side in the longitudinal direction of the case body and is connected to an electrode terminal provided on the second lid, It is equipped with A power storage device as described in any one of items 1 to 5. [Section 7] The process involves preparing a rectangular tubular case body with openings on both sides in the longitudinal direction, The process of preparing the electrode body to be housed in the above-mentioned case body, The process involves covering the above electrode body with an insulating film, The steps include inserting the electrode body covered with the insulating film into the case body, Equipped with, The case body mentioned above is A pair of opposing wide surfaces, A pair of opposing narrow surfaces, continuous with the pair of wide surfaces mentioned above, It has, The electrode body described above is It is housed in the internal space of the case body and has a laminated structure in which a positive electrode and a negative electrode are stacked between the pair of opposing wide surfaces with a separator in between. The above insulating film is The case body has a circumferential portion facing the inner surface and a pocket portion that surrounds at least a part of the rear end of the electrode body when it is inserted into the case body. In the insertion process described above, the tip of the electrode body, while housed in the insulating film, is inserted into one of the openings of the case body. A method for manufacturing energy storage devices. [Section 8] The above insulating film is heat-sealed to form the above bag portion. A method for manufacturing the energy storage device described in item 7. [Section 9] The above insulating film, when viewed in the longitudinal direction, further comprises a gripping portion at the end on the tip side of the electrode body. In the insertion process described above, the electrode body and the insulating film are inserted while gripping the gripping portion. A method for manufacturing an energy storage device as described in item 7 or 8. [Section 10] The insertion process is performed while pushing the bag portion toward the tip of the electrode body. A method for manufacturing an energy storage device as described in any one of items 7 to 9. [Section 11] The above insulating film has through holes as gripping portions, In the insertion process described above, the electrode body and the insulating film are inserted while grasping the through-hole. A method for manufacturing an energy storage device as described in item 9 or 10. [Explanation of Symbols]

[0080] 10 cases 12 Case body 12a Narrow surface (top surface) 12c Narrow side (bottom side) 12b, 12d Wide surface 12e1,12e2 End 12h1,12h2 opening 13 Gas discharge valve 14. First Lid 16. Second Lid 20 Electrode body 20a, 20c narrow side 20b, 20d wide surface 20g corner 50, 150, 250, 350 insulating film 52 Peripheral part 52a 1st page 52b Page 2 52c 3rd page 52d 4th page 52e 5th page 54, 154 bag section 56, 256, 356 gripping parts 100 Energy Storage Devices 500 Push-in blocks 510 Base section 600 Chuck 610 Claw part 620 Arm section

Claims

1. A rectangular tubular case body with openings at both ends in the longitudinal direction, The electrode body housed in the aforementioned case body, An insulating film is placed between the inner circumferential surface of the case body and the electrode body, and covers the electrode body. A first lid is attached to the first opening in the longitudinal direction of the case body, A second lid is attached to the second opening in the longitudinal direction of the case body, Equipped with, The aforementioned case body is A pair of opposing wide surfaces, A pair of opposing narrow surfaces continuous with the pair of wide surfaces It has, The electrode body is The internal space of the case body is housed, The device has a laminated structure in which a positive electrode and a negative electrode are stacked between the pair of opposing wide surfaces with a separator in between. The aforementioned insulating film is On the first side, the electrode body is provided with a bag portion that surrounds the corner portion, which is composed of a portion facing the pair of wide surfaces, a portion facing one of the pair of narrow surfaces, and a portion facing the first lid. The bag portion is composed of a series of integrated films. Energy storage device.

2. The aforementioned bag portion is formed by heat-sealing the film to create a single, integrated bag-like structure. The energy storage device according to claim 1.

3. The insulating film further includes a gripping portion at the second end of the electrode body. The energy storage device according to claim 1 or 2.

4. The insulating film has through holes as gripping portions. The energy storage device according to claim 3.

5. Multiple through holes are provided symmetrically when viewed in the height direction of the case body. The energy storage device according to claim 4.

6. The electrode body is A first electrode tab extends toward the first side in the longitudinal direction of the case body and is connected to an electrode terminal provided on the first lid, A second electrode tab extends toward the second side in the longitudinal direction of the case body and is connected to an electrode terminal provided on the second lid, It is equipped with The energy storage device described in claim 1.

7. The process involves preparing a rectangular tubular case body with openings on both sides in the longitudinal direction, The process of preparing an electrode body to be housed in the case body, The process of covering the electrode body with an insulating film, The steps include inserting the electrode body covered with the insulating film into the case body, Equipped with, The aforementioned case body is A pair of opposing wide surfaces, A pair of opposing narrow surfaces continuous with the pair of wide surfaces, It has, The electrode body is It is housed in the internal space of the case body and has a laminated structure in which a positive electrode and a negative electrode are stacked between the pair of opposing wide surfaces with a separator in between. The aforementioned insulating film is The case body has a circumferential portion facing the inner surface of the case body and a pocket portion that surrounds at least a part of the rear end of the electrode body when it is inserted into the case body. In the insertion step, the tip end of the electrode body, while housed in the insulating film, is inserted into one of the openings of the case body. A method for manufacturing energy storage devices.

8. The bag portion is formed by heat-sealing the insulating film. A method for manufacturing an energy storage device according to claim 7.

9. The insulating film further includes a gripping portion at the end of the electrode body on the tip side when viewed in the longitudinal direction. In the insertion step, the electrode body and the insulating film are inserted while gripping the gripping portion. A method for manufacturing an energy storage device according to claim 7 or 8.

10. The insertion process is performed while pushing the bag portion toward the tip of the electrode body. A method for manufacturing an energy storage device according to claim 6 or 7.

11. The insulating film has through holes as gripping portions, In the insertion step, the electrode body and the insulating film are inserted while grasping the through hole. A method for manufacturing an energy storage device according to claim 9.

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