Energy Storage Devices

Abstract

To reduce the risk of a damage inside an electrode body due to injection of an electrolyte solution.SOLUTION: A power storage device 100 includes an electrode body 20, an electrolyte solution, an exterior body 12, a sealing plate 14, and a current collector body 50. The electrode body 20 includes an electrode tab 22t. The exterior body 12 has an opening 12h, and accommodates the electrode body 20 and the electrolyte solution. The sealing plate 14 is a member that covers the opening 12h, and a liquid injection hole 15 for injecting the electrolyte solution into the exterior body 12 is provided. The current collector body 50 is attached to the sealing plate 14 and is electrically connected to the electrode body 20 through the electrode tab 22t. In the sealing plate 14, the liquid injection hole 15 is provided so as not to overlap with a part where the current collector body 50 is attached. Between the liquid injection hole 15 and the electrode body 20, a shielding part 80 to prevent the electrolyte solution injected from the liquid injection hole 15 from being in contact with the electrode body 20 directly is provided.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an electricity storage device. [Background technology]

[0002] Patent Document 1 discloses an electric storage device including an electrode body, an exterior body that houses the electrode body, a lid that covers the exterior body, and an electrode terminal. The lid of the electric storage device is provided with a liquid injection hole for injecting an electrolyte into the exterior body. The lid is provided with a cylinder extending from the lid toward the electrode body so as to surround the opening of the liquid injection hole on the surface of the lid facing the electrode body. The cylinder is connected to the cylinder and includes a shielding portion interposed between the liquid injection hole and the electrode body. This document describes that the provision of the shielding portion can reduce the flow rate of the electrolyte when the electrolyte injected into the exterior body collides with the electrode body. The document describes that this can suppress the occurrence of damage, peeling, and slipping of the material of the electrode body.

[0003] In this document, the cover is provided with a current collector that electrically connects the electrode body and the electrode terminal. A through hole is provided in the current collector, and a cylinder is inserted into the through hole. In addition, to connect the electrode body and the current collector terminal, a tab extending from the electrode body is attached to the current collector. At this time, the tip of the tab faces the side surface of the cylinder inserted into the through hole. In addition, the electricity storage device in this document has two electrode bodies, and the cylinder is sandwiched between a tab extending from one electrode body and a tab extending from the other electrode body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-129129 A Summary of the Invention [Problem to be solved by the invention]

[0005] In an electricity storage device having a configuration in which the electrode tab is disposed on the lid side, the electrode stacking surface of the electrode body may face the lid. In this case, if the electrolyte is injected from the lid side, the injected electrolyte directly hits the stacking surface, and there is a risk of damaging the inside of the electrode body. In particular, if the injected electrolyte directly hits the electrode tab, the electrode tab is likely to induce the electrolyte to enter the electrode body. The present inventors would like to reduce the risk of the inside of the electrode body being damaged by the injection of the electrolyte. [Means for solving the problem]

[0006] The power storage device disclosed herein includes an electrode assembly having an electrode tab, an electrolyte, an exterior body having an opening and accommodating the electrode assembly and the electrolyte, a sealing plate that closes the opening and has an injection hole for injecting the electrolyte into the exterior body, and a current collector that is attached to the sealing plate and electrically connected to the electrode assembly via the electrode tab. In the sealing plate, the injection hole is provided so as not to overlap with a portion where the current collector is attached. Here, a shielding portion is provided between the injection hole and the electrode assembly to prevent the electrolyte injected from the injection hole from directly hitting the electrode assembly.

[0007] In the electricity storage device having such a configuration, the liquid injection hole is provided in the sealing plate so as not to overlap with the mounting portion of the current collector to which the electrode tab is attached. This allows the portion into which the electrolyte is injected to be removed from the portion that is likely to cause damage to the electrode body due to impact from the injection. In addition, by providing a shielding portion between the electrolyte injection hole and the electrode body, it is possible to prevent the electrolyte injected from the electrolyte injection hole from directly hitting the electrode body. This reduces the risk of the inside of the electrode body being damaged by the injection of the electrolyte.

[0008] In a preferred embodiment, the electricity storage device disclosed herein includes an insulating member between the sealing plate and the current collector. The insulating member includes a main body portion disposed between the sealing plate and the current collector, and the plate-shaped shielding portion extending outward from the main body portion. In an insulating member having such a configuration, the main body portion and the shielding portion are integrally formed. Therefore, in addition to the above-mentioned effect, it is possible to realize the effect of omitting the use of a separate member for attaching the shielding portion.

[0009] It is preferable that the shielding portion is inclined toward the electrode assembly. With this configuration, it is possible to guide the flow of the electrolyte in the shielding portion. Therefore, it is possible to more effectively reduce the risk of internal damage to the electrode assembly.

[0010] In addition, it is preferable that a tip of the shielding portion contacts an upper end of the electrode body facing the sealing plate. With this configuration, in addition to the above-mentioned effects, it is possible to achieve an effect of suppressing movement of the electrode body.

[0011] In another preferred embodiment of the electricity storage device disclosed herein, the width of the tip end of the shielding portion is smaller than the width of the base end of the shielding portion. With this configuration, the effect of reducing the risk of internal damage to the electrode body can be further improved.

[0012] The shielding portion may be a substantially rectangular plate having a straight portion at its tip and two curved portions at both ends of the straight portion, which is suitable for improving the above-mentioned effects.

[0013] The tip may be rounded or polygonal having four or more sides, which is preferable for improving the above-mentioned effect.

[0014] In another preferred aspect of the electricity storage device disclosed herein, a slit is provided on the surface of the shielding portion facing the sealing plate. With this configuration, the effect of reducing the risk of internal damage to the electrode assembly can be further improved. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a vertical cross-sectional view of an electricity storage device 100. As shown in FIG. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. [Diagram 3] FIG. 3 is a perspective view of the first insulating member 91. As shown in FIG. [Figure 4] FIG. 4 is a vertical cross-sectional view of the electricity storage device 200. As shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, one embodiment of the power storage device disclosed herein will be described. The embodiment described herein is not intended to limit the technology disclosed herein, as a matter of course. The technology disclosed herein is not limited to the embodiment described herein, unless otherwise specified. Each drawing is drawn typically and does not necessarily reflect the actual product. In addition, the same reference numerals are appropriately used for members and parts that perform the same function, and duplicated explanations are omitted. In addition, the notation "A to B" indicating a numerical range means "A or more and B or less" unless otherwise specified, and also includes the meaning of "greater than A and less than B".

[0017] In this specification, the term "electricity storage device" refers to a device in which a charge / discharge reaction occurs by the movement of charge carriers between a pair of electrodes (positive and negative electrodes) via an electrolyte. Such electricity storage devices include secondary batteries such as lithium ion secondary batteries, nickel-metal hydride batteries, and nickel-cadmium batteries; and capacitors such as lithium ion capacitors and electric double layer capacitors. In the following, an embodiment in which a lithium ion secondary battery is used as an example of the above-mentioned electricity storage device will be described.

[0018] First Embodiment FIG. 1 is a vertical cross-sectional view of the power storage device 100. FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1. FIG. 1 shows a state in which the inside is exposed along the wide surface 12b of the exterior body 12 of the power storage device 100. FIG. 2 shows a state in which the inside is exposed along the narrow surface 12c of the exterior body 12 of the power storage device 100. In addition, the symbols L, R, U, D, F, and Rr in the drawings represent left, right, top, bottom, front, and back. In addition, the symbol X in the drawings represents the short side direction of the power storage device 100, the symbol Y represents the long side direction of the power storage device 100, and the symbol Z represents the up-down direction (height direction) of the power storage device 100. However, these are merely directions for convenience of explanation and do not limit the installation form of the power storage device 100 in any way.

[0019] 1 and 2, the electricity storage device 100 includes an exterior body 12, a sealing plate 14, an electrode body 20, a positive electrode terminal 30, a negative electrode terminal 40, a positive electrode current collector 50, a negative electrode current collector 60, an insulating member, and a shielding portion 80. The electricity storage device 100 here is a lithium ion secondary battery. Although not shown in the drawings, the electricity storage device 100 here further includes an electrolyte solution.

[0020] The exterior body 12 is, for example, a housing that houses the electrode body 20. As shown in FIG. 1 and FIG. 2, the exterior body 12 has an opening 12h, a bottom surface 12a, a pair of wide surfaces 12b, and a pair of narrow surfaces 12c. In this embodiment, the bottom surface 12a is substantially rectangular and faces the opening 12h. The pair of wide surfaces 12b extend from a pair of opposing long sides of the bottom surface 12a. The pair of narrow surfaces 12c extend from a pair of opposing short sides of the bottom surface 12a. In this embodiment, the area of ​​the wide surfaces 12b is larger than the area of ​​the narrow surfaces 12c. The opening 12h is substantially rectangular, and a sealing plate 14 is attached to it. The sealing plate 14 is joined to the periphery of the opening 12h, so that the exterior body 12 and the sealing plate 14 are integrated and hermetically sealed.

[0021] The sealing plate 14 is, for example, a flat plate-like member that seals the opening 12h. The sealing plate 14 may have a shape corresponding to the shape of the opening 12h. In this embodiment, the sealing plate 14 is substantially rectangular. As shown in FIG. 1 and FIG. 2, the sealing plate 14 has a pair of opposing long side portions 14a and a pair of opposing short side portions 14b. In FIG. 1, the pair of short side portions 14b are disposed at the left end and the right end, respectively. As shown in FIG. 1, the sealing plate 14 is provided with, for example, a liquid injection hole 15 and a discharge valve 17. The liquid injection hole 15 is for injecting an electrolyte into the exterior body 12 after the sealing plate 14 is assembled to the exterior body 12. The liquid injection hole 15 is sealed by a sealing member 16. The discharge valve 17 is a thin-walled portion configured to break when the pressure inside the exterior body 12 after the sealing reaches a predetermined value or more, and to discharge the internal gas to the outside.

[0022] The electrode body 20 is, for example, a power generating element of the electricity storage device 100. As shown in FIG. 2, the electricity storage device 100 includes two electrode bodies 20 arranged next to each other. The two adjacent electrode bodies 20 are housed in the exterior body 12 while being covered by an electrode body holder 29, as shown in FIG. 1 and FIG. 2. As shown in FIG. 1, the electrode body 20 includes a rectangular sheet-shaped positive electrode plate 22, a rectangular sheet-shaped negative electrode plate 24, and a separator 70 as a separator. The positive electrode plate 22 and the negative electrode plate 24 have a laminated structure in which they are laminated with the separator 70 interposed therebetween. Here, the electrode body 20 is exemplified as a so-called laminated electrode body in which the positive electrode plate 22 and the negative electrode plate 24 formed in a predetermined shape are laminated with the separator 70 interposed therebetween.

[0023] As shown in FIG. 1, the positive electrode plate 22 includes a substantially rectangular positive electrode current collector foil 22c and a positive electrode active material layer 22a formed on the positive electrode current collector foil 22c. The positive electrode active material layer 22a is formed on both side surfaces of the positive electrode current collector foil 22c. In this embodiment, the formation region of the positive electrode active material layer 22a is rectangular. The positive electrode plate 22 has a positive electrode tab 22t protruding from one side of the formation region of the positive electrode active material layer 22a. The positive electrode tab 22t is a part of the positive electrode current collector foil 22c, and is an active material layer unformed portion on the surface of which the positive electrode active material layer 22a is not formed. In this embodiment, a positive electrode protective layer 22p is formed at the boundary between the positive electrode active material layer 22a and the positive electrode tab 22t. Here, the positive electrode protective layer 22p is formed at an end of the positive electrode active material layer 22a in the protruding direction of the positive electrode tab 22t, and is adjacent to the positive electrode tab 22t. It should be noted that the formation of the positive electrode protection layer 22p is not essential.

[0024] The positive electrode current collector foil 22c may be, for example, an aluminum foil. The positive electrode active material layer 22a is a layer containing a positive electrode active material. In a lithium ion secondary battery, the positive electrode active material is, for example, a material that can release lithium ions during charging and absorb lithium ions during discharging, such as a lithium transition metal composite material. In general, various positive electrode active materials have been proposed other than the lithium transition metal composite material, and are not particularly limited. The positive electrode protective layer 22p is, for example, a layer containing an inorganic filler such as alumina.

[0025] As shown in FIG. 1, the negative electrode plate 24 includes a substantially rectangular negative electrode current collector foil 24c and a negative electrode active material layer 24a formed on the negative electrode current collector foil 24c. The negative electrode active material layer 24a is formed on each of both side surfaces of the negative electrode current collector foil 24c. In this embodiment, the formation region of the negative electrode active material layer 24a is rectangular. The negative electrode plate 24 has a negative electrode tab 24t protruding from one side of the formation region of the negative electrode active material layer 24a. The negative electrode tab 24t is a part of the negative electrode current collector foil 24c, and is an active material layer unformed portion on which the negative electrode active material layer 24a is not formed.

[0026] The negative electrode current collector foil 24c may be, for example, a copper foil. The negative electrode active material layer 24a is a layer containing a negative electrode active material. In a lithium ion secondary battery, the negative electrode active material is, for example, a material that can absorb lithium ions during charging, such as natural graphite, and release the absorbed lithium ions during charging during discharging. In general, various negative electrode active materials have been proposed other than natural graphite, and are not particularly limited.

[0027] In this embodiment, the separator 70 is substantially rectangular and is formed to be slightly larger than the negative electrode active material layer 24a so as to cover the negative electrode active material layer 24a. For example, a porous resin sheet through which an electrolyte having a required heat resistance can pass is used for the separator 70. Various types of separator 70 have been proposed, and there is no particular limitation.

[0028] As shown in FIG. 1, the width P2 of the negative electrode active material layer 24a in the long side direction of the bottom surface 12a is larger than the width P1 of the positive electrode active material layer 22a in the same direction. The width P3 of the separator 70 in the long side direction of the bottom surface 12a is larger than the width P2 of the negative electrode active material layer 24a. The positive electrode tab 22t and the negative electrode tab 24t have a required length so as to protrude from the separator 70. As shown in FIG. 1, the positive electrode plate 22, the negative electrode plate 24, and the separator 70 are overlapped with the separator 70 interposed therebetween so that the negative electrode active material layer 24a covers the positive electrode active material layer 22a, and the positive electrode tab 22t and the negative electrode tab 24t each protrude from the separator 70. In this embodiment, in a rectangular region formed by stacking the positive electrode plate 22 and the negative electrode plate 24 with the separator 70 interposed therebetween, a positive electrode active material layer 22a is formed on both sides of the positive electrode plate 22, and a negative electrode active material layer 24a is formed on both sides of the negative electrode plate 24. At one end of the rectangular region (here, the upper end 20e of the electrode body 20), a plurality of positive electrode tabs 22t protrude in a superimposed state. At the one end, a plurality of negative electrode tabs 24t protrude in a superimposed state.

[0029] As shown in Fig. 1 and Fig. 2, the electrode body 20 has a main body excluding the positive electrode tab 22t and the negative electrode tab 24t, which has a flat rectangular parallelepiped shape having a pair of wide rectangular surfaces 20a. In this embodiment, the end faces in the stacking direction (direction X in Fig. 2) of each electrode plate and separator 70 constitute the wide rectangular surfaces 20a. The four side surfaces of the main body excluding the pair of wide rectangular surfaces 20a are stacking surfaces of the positive electrode plate 22, the negative electrode plate 24, and the separator 70.

[0030] The positive electrode terminal 30 is, for example, a member electrically connected to the positive electrode plate 22 of the electrode body 20. As shown in FIG. 1, the positive electrode terminal 30 is inserted into the terminal pull-out hole 18 and exposed to the outer surface of the sealing plate 14. Here, the positive electrode terminal 30 has a first conductive member 31 and a second conductive member 32. The first conductive member 31 has an axis portion 31a and a base portion 31b. The axis portion 31a is, for example, cylindrical, and is inserted into the terminal pull-out hole 18 and the through hole of the second conductive member 32, and is also inserted into the through hole 50h of the positive electrode current collector 50. The base portion 31b is, for example, flat, and is disposed along the outer surface of the sealing plate 14. In the embodiment shown in FIG. 1, the second conductive member 32 is, for example, flat, and is disposed along the outer surface of the sealing plate 14. The first conductive member 31 and the second conductive member 32 are connected to each other on the outer surface side of the sealing plate 14. The first conductive member 31 may be made of, for example, aluminum or an aluminum alloy. The second conductive member 32 may be made of, for example, aluminum, an aluminum alloy, copper, a copper alloy, or the like.

[0031] The negative electrode terminal 40 is, for example, a member electrically connected to the negative electrode plate 24 of the electrode body 20. As shown in FIG. 1, the negative electrode terminal 40 is inserted into the terminal pull-out hole 19 and exposed to the outer surface of the sealing plate 14. Here, the negative electrode terminal 40 has a first conductive member 41 and a second conductive member 42. The first conductive member 41 may be made of, for example, copper or a copper alloy. In addition, the negative electrode terminal 40 may have the same configuration as the positive electrode terminal 30. For this reason, a description of the configuration of the negative electrode terminal 40 will be omitted here.

[0032] The positive electrode collector 50 is, for example, a member electrically connected to the electrode body 20 via a plurality of stacked positive electrode tabs 22t. The positive electrode collector 50 is, for example, a rectangular flat conductive member. In the embodiment shown in FIG. 1, the positive electrode collector 50 extends along the inner surface of the sealing plate 14. In the embodiment shown in FIG. 1, the positive electrode collector 50 is attached to the sealing plate 14 so as not to overlap with the liquid injection hole 15. The positive electrode collector 50 has a through hole 50h. The positive electrode terminal 30 is inserted into the through hole 50h. In addition, the positive electrode collector 50 is joined to a plurality of stacked positive electrode tabs 22t. The positive electrode collector 50 can be made of, for example, aluminum or an aluminum alloy.

[0033] The negative electrode collector 60 is, for example, a member electrically connected to the electrode body 20 via a plurality of overlapping negative electrode tabs 24t. The negative electrode collector 60 is, for example, a rectangular flat conductive member. In the embodiment shown in FIG. 1, the negative electrode collector 60 extends along the inner surface of the sealing plate 14. In the embodiment shown in FIG. 1, the negative electrode collector 60 is attached to the sealing plate 14 so as not to overlap the liquid injection hole 15. The negative electrode collector 60 has a through hole 60h. The negative electrode terminal 40 is inserted into the through hole 60h. In addition, the negative electrode collector 60 is joined to a plurality of overlapping negative electrode tabs 24t. The negative electrode collector 60 can be made of, for example, copper or a copper alloy.

[0034] Various insulating members are used in the electricity storage device 100. The electricity storage device 100 includes, for example, an electrode body holder 29, a gasket 90, first insulating members 91 and 92, and a second insulating member 93 (see Figs. 1 and 2). The electrode body holder 29 is, for example, a member that prevents conduction between the electrode body 20 and the exterior body 12. Here, the electrode body 20 is disposed inside the exterior body 12 while being covered by the electrode body holder 29. The electrode body holder 29 is, for example, made of an insulating resin sheet.

[0035] The gasket 90 and the second insulating member 93 are members that prevent, for example, electrical conduction between the positive terminal 30 and the sealing plate 14, and between the negative terminal 40 and the sealing plate 14. Here, the gasket 90 is disposed between the first conductive member 31 on the positive electrode side and the outer surface of the sealing plate 14, and between the first conductive member 41 on the negative electrode side and the outer surface of the sealing plate 14. The gasket 90 is also attached to the inner periphery of the terminal drawing hole 18 and the inner periphery of the terminal drawing hole 19. Here, the second insulating member 93 is disposed between the second conductive member 32 on the positive electrode side and the outer surface of the sealing plate 14, and between the second conductive member 42 on the negative electrode side and the outer surface of the sealing plate 14.

[0036] FIG. 3 is a perspective view of the first insulating member 91. FIG. 3 shows a perspective view of the first insulating member 91 as viewed from the first surface 91a on the sealing plate 14 side in FIG. 1. The first insulating member 91 is, for example, a member that prevents conduction between the positive electrode current collector 50 and the sealing plate 14. Here, the first insulating member 91 is disposed between the positive electrode current collector 50 and the inner surface of the sealing plate 14. As shown in FIG. 1 and FIG. 3, the first insulating member 91 has a main body portion 911 and a shielding portion 80. The main body portion 911 is, for example, a portion disposed between the sealing plate 14 and the positive electrode current collector 50. As shown in FIG. 3, the main body portion 911 has a flat portion 912 and a wall portion 913. The flat portion 912 is, for example, a rectangular flat plate, and is a portion where the positive electrode current collector 50 is disposed. In the embodiment shown in FIG. 1, the flat portion 912 is attached to the inner surface of the sealing plate 14 with the first surface 91a facing the inner surface of the sealing plate 14 and the second surface 91b facing the electrode body. Here, the positive electrode collector 50 is disposed on the second surface 91b. In FIG. 1, the second surface 91b is the surface opposite to the first surface 91a, and is the surface facing the electrode body 20 housed in the exterior body 12. Here, the flat portion 912 has a through hole 91h. When the positive electrode collector 50 is disposed on the flat portion 912, for example, the through hole 50h of the positive electrode collector 50 is overlapped with the through hole 91h. For example, a part of the gasket 90 is inserted into the through hole 91h.

[0037] The wall portion 913 is, for example, a portion surrounding the periphery of the positive electrode current collector 50 disposed on the flat portion 912 (here, the second surface 91b). As shown in FIG. 1 and FIG. 3, the wall portion 913 extends from the periphery of the flat portion 912 (here, the periphery of the second surface 91b). In the embodiment shown in FIG. 1, the wall portion 913 extends toward the electrode body 20. As shown in FIG. 3, the wall portion 913 has a pair of opposing first wall portions 913a, 913b and a pair of opposing second wall portions 913c, 913d. The first wall portions 913a, 913b are, for example, approximately parallel to the short side portion 14b of the sealing plate 14. The first wall portion 913a is, for example, disposed on the center side of the sealing plate 14 (the liquid injection hole 15 side in FIG. 1) (see FIG. 1). The first wall portion 913b is disposed, for example, at the left end portion of the sealing plate 14 (see FIG. 1). The second wall portions 913c and 913d are, for example, substantially parallel to the long side portion 14a of the sealing plate 14. The second wall portion 913c is disposed, for example, on the front side of the sealing plate 14 (not shown). The second wall portion 913d is disposed, for example, on the rear side of the sealing plate 14 (not shown).

[0038] A shielding portion 80 is provided at an extending end 913e of the wall portion 913. Here, the shielding portion 80 is provided at an extending end 913e of the first wall portion 913a. In this embodiment, the main body portion 911 of the first insulating member 91 is integrally formed with the shielding portion 80. By providing the shielding portion 80 so as to extend from the main body portion 911 in the first insulating member 91, it is possible to omit using a separate member for attaching the shielding portion 80. The first insulating member 91 is an example of an "insulating member" in the electricity storage device disclosed herein.

[0039] The shielding portion 80 is, for example, a member that shields the electrode body 20 from the electrolyte injected from the injection hole 15. The shielding portion 80 is, for example, substantially rectangular plate-shaped. As shown in FIG. 1, the shielding portion 80 is provided between the injection hole 15 and the electrode body 20. In this embodiment, the upper surface 80u of the shielding portion 80 is disposed on the inner surface side of the sealing plate 14. Here, the upper surface 80u is a surface that receives the electrolyte injected from the injection hole 15, and serves as a flow path for the electrolyte. In addition, the lower surface 80d is disposed on the upper end 20e side of the electrode body 20. As described above, the shielding portion 80 is integrally formed with the first insulating member 91. In this embodiment, the shielding portion 80 extends outward from the extension end 913e of the wall portion 913. The extension direction of the shielding portion 80 is indicated by an arrow T in FIG. 3. In the following description, such a direction is also simply referred to as the "extension direction T".

[0040] In the embodiment shown in FIG. 3, the shielding portion 80 is inclined with respect to the flat portion 912. As shown in FIG. 1, the shielding portion 80 is inclined with respect to the sealing plate 14 and toward the electrode body 20. This makes it possible to induce the flow of the electrolyte from the shielding portion 80 to the electrode body 20. Therefore, the flow direction of the electrolyte can be adjusted, and the impact of the electrolyte dropping from the shielding portion 80 on the electrode body 20 can be reduced. From this viewpoint, the inclination angle of the shielding portion 80 with respect to the upper end 20e of the electrode body may be set to, for example, more than 10 degrees and not more than 40 degrees. Note that the upper end 20e is the end of the electrode body 20 on the sealing plate 14 side in FIG. 1.

[0041] In this embodiment, the tip 802 of the shielding portion 80 is in contact with the upper end 20e of the electrode body 20. This makes it possible to better guide the flow of the electrolyte from the shielding portion 80 to the electrode body 20. This makes it possible to further reduce the impact of the electrolyte dropping from the shielding portion 80 on the electrode body 20. In addition, it is possible to suppress the electrode body 20 from moving in the height direction of the electricity storage device 100. Note that the tip 802 of the shielding portion 80 is an end in the extension direction T in FIG. 1 and FIG. 3, and is an end opposite to the base end 801.

[0042] In this embodiment, width W2 of tip 802 of shielding portion 80 is set to be smaller than width W1 of base end 801 (see FIG. 3). This makes it possible to disperse the direction in which the electrolyte falls at tip 802. This makes it possible to reduce the impact of the electrolyte falling from shielding portion 80. In this specification, the "width" of shielding portion 80 refers to the length in width direction S of shielding portion 80 that is perpendicular to direction T.

[0043] In the embodiment shown in FIG. 3, the shielding part 80 has a straight part 81 and two curved parts 82 at the tip 802. The two curved parts 82 are provided at both ends of the straight part 81. As described above, in this embodiment, the shielding part 80 is a substantially rectangular plate, and the two corners of the tip 802 are cut off so as to be curved. As a result, the straight part 81 having a width W2 smaller than the width W1 of the base end 801 is provided at the tip 802, and the curved parts 82 are provided at both ends of the straight part 81. In the shielding part 80, the electrolyte injected from the injection hole 15 flows, for example, on the upper surface 80u toward the tip 802, and falls from the straight part 81 and the two curved parts 82 toward the electrode body 20. In this way, in the shielding part 80, the direction in which the electrolyte falls at the tip can be dispersed. Therefore, the impact of the falling electrolyte on the electrode body 20 can be reduced.

[0044] The first insulating member 92 is, for example, a member that prevents conduction between the negative electrode current collector 60 and the sealing plate 14. Here, the first insulating member 92 is disposed between the negative electrode current collector 60 and the inner surface of the sealing plate 14. As shown in FIG. 1, the first insulating member 92 includes a through hole 92h, a flat portion 921, and a wall portion 922. Here, the first insulating member 92 does not include the shielding portion 80. Other than that, the first insulating member 92 has the same configuration as the first insulating member 91 on the positive electrode side. For this reason, a description of the configuration of the first insulating member 92 will be omitted here.

[0045] The materials constituting the electrode body holder 29, the gasket 90, the first insulating members 91, 92, and the second insulating member 93 are not particularly limited. Examples of such constituent materials include synthetic resin materials such as polyolefin resins such as polypropylene (PP) and polyethylene (PE); and fluorine-based resins such as perfluoroalkoxyalkane and polytetrafluoroethylene (PTFE). In this embodiment, the material constituting the shielding portion 80 is the same as the material constituting the first insulating member 91.

[0046] As described above, the electricity storage device 100 includes the electrode body 20, the electrolyte, the exterior body 12, the sealing plate 14, and the positive electrode current collector 50. The electrode body 20 has a positive electrode tab 22t. The exterior body 12 has an opening 12h and accommodates the electrode body 20 and the electrolyte. The sealing plate 14 is a member that closes the opening 12h, and is provided with a liquid injection hole 15 for injecting the electrolyte into the exterior body 12. The positive electrode current collector 50 is attached to the sealing plate 14 and is electrically connected to the electrode body 20 via the positive electrode tab 22t. In the sealing plate 14, the liquid injection hole 15 is provided so as not to overlap with the portion where the positive electrode current collector 50 is attached. Between the liquid injection hole 15 and the electrode body 20, a shielding portion 80 is provided to prevent the electrolyte injected from the liquid injection hole 15 from directly hitting the electrode body 20.

[0047] In the electricity storage device 100, the liquid injection hole 15 is provided in the sealing plate 14 so as not to overlap with the mounting portion of the positive electrode current collector 50 to which the positive electrode tab 22t is attached. This makes it possible to suppress, for example, the electrolyte from pouring into the electrode body 20 along the positive electrode tab 22t when the electrolyte is injected. This makes it possible to suppress injection into a portion that is particularly likely to cause damage to the electrode body 20 due to an impact from the injected electrolyte. In addition, by providing a shielding portion 80 between the electrolyte injection hole 15 and the electrode body 20, it is possible to suppress the electrolyte injected from the electrolyte injection hole 15 from directly hitting the electrode body 20. This makes it possible to reduce the risk of damage to the electrode body 20 due to an impact when the electrolyte is injected.

[0048] The electricity storage device 100 can be used for various purposes, and can be suitably used, for example, as a power source (driving power source) for motors mounted on various vehicles such as passenger cars, trucks, etc. The type of vehicle is not particularly limited, and examples thereof include a plug-in hybrid vehicle (PHEV), a hybrid electric vehicle (HEV), and a battery electric vehicle (BEV).

[0049] Although the embodiment of the technology disclosed herein has been described above, it is not intended that the technology disclosed herein be limited to the above embodiment. The technology disclosed herein may be implemented in other embodiments. The technology described in the claims includes various modifications and changes to the above-exemplified embodiments. For example, it is possible to replace a part of the above-described embodiment with another modified embodiment, and it is also possible to add another modified embodiment to the above-described embodiment. Furthermore, if a technical feature is not described as essential, it is also possible to delete it as appropriate.

[0050] <Second embodiment> For example, in the first embodiment, the extended shielding portion 80 extends obliquely from the first insulating member 91 toward the electrode body 20. However, the present invention is not limited to this. FIG. 4 is a longitudinal sectional view of the electricity storage device 200. As shown in FIG. 4, the electricity storage device 200 includes a shielding portion 280. The electricity storage device 200 also includes a first insulating member 91 between the sealing plate 14 and the positive electrode current collector 50. In this embodiment, the shielding portion 280 extends from a main body portion 911 of the first insulating member 91. The base end 281 of the shielding portion 280 is provided, for example, at an extended end 913e of a wall portion 913 of the first insulating member 91 (for example, the extended end 913e of the first wall portion 913a. See FIG. 3). In the embodiment shown in FIG. 4, the shielding portion 280 is approximately parallel to the sealing plate 14. The inclination angle of the shielding portion 280 with respect to the upper end 20e of the electrode body may be set to, for example, -10 degrees to +10 degrees (e.g., -5 degrees to +5 degrees). Therefore, in this embodiment, the tip 282 of the shielding portion 280 does not contact the upper end 20e of the electrode body 20. In addition, in FIG. 4, the reference symbol "280u" indicates the upper surface of the shielding portion 280. Furthermore, the reference symbol "280d" indicates the lower surface of the shielding portion 280.

[0051] <Other embodiments> In the first and second embodiments, the shielding portion 80 or the shielding portion 280 and the first insulating member 91 are integrally formed. However, this is not limited thereto. The shielding portion 80 and the shielding portion 280 may be separate from the first insulating member 91. Also, in the first and second embodiments, the shielding portion 80 or the shielding portion 280 is provided in the first insulating member 91 on the positive electrode side. However, this is not limited thereto. The shielding portion 80 and the shielding portion 280 may be provided in the first insulating member 92 on the negative electrode side.

[0052] Furthermore, the shape of the tip 802, 282 of the shielding portion 80, 280 does not have to be that described in the above embodiment. The shape of the tip 802, 282 may be, for example, an R-shape. Furthermore, the shape of the tip 802, 282 may be a polygonal shape having four or more sides. By making the tip 802, 282 have such a shape, the effect of dispersing the direction in which the electrolyte falls at the tip 802, 282 can be further improved.

[0053] Alternatively, a slit may be provided on the surface (here, the upper surface 80u, 280u) of the shielding portion 80, 280 on the sealing plate 14 side. By providing a slit on the shielding portion 80, 280, the flow of the electrolyte can be guided better. From this viewpoint, the slit may be provided, for example, along the direction T in which the shielding portion 80, 280 extends.

[0054] As described above, specific aspects of the technology disclosed herein include those described in the following sections. Section 1: an electrode body having an electrode tab; An electrolyte; an exterior body having an opening and accommodating the electrode assembly and the electrolyte; a sealing plate that closes the opening, the sealing plate having a liquid injection hole through which the electrolyte is injected into the exterior body; a current collector attached to the sealing plate and electrically connected to the electrode assembly via the electrode tab; A power storage device comprising: the liquid injection hole is provided in the sealing plate so as not to overlap with a portion where the current collector is attached, In this electricity storage device, a shielding portion is provided between the liquid injection hole and the electrode body to prevent the electrolyte injected from the liquid injection hole from directly contacting the electrode body. Section 2: An insulating member is provided between the sealing plate and the current collector, The insulating member is a main body portion disposed between the sealing plate and the current collector; The shielding portion has a plate shape and extends outward from the main body portion; Item 1. The power storage device according to item 1, Section 3: Item 3. The power storage device according to item 1 or 2, wherein the shielding portion is inclined toward the electrode body. Section 4: 4. The electricity storage device according to any one of items 1 to 3, wherein a tip of the shielding portion is in contact with an upper end of the electrode body that faces the sealing plate. Section 5: 5. The electricity storage device according to any one of items 1 to 4, wherein a width of a tip end of the shielding portion is smaller than a width of a base end of the shielding portion. Item 6: The shielding portion is It is a substantially rectangular plate-like shape, 6. The electricity storage device according to any one of items 1 to 5, comprising a straight portion at a tip and two curved portions at both ends of the straight portion. Section 7: 7. The electricity storage device according to any one of items 1 to 6, wherein the tip is rounded or has a polygonal shape with four or more sides. Section 8: 8. The electricity storage device according to any one of items 1 to 7, wherein a slit is provided on a surface of the shielding part on the sealing plate side. [Explanation of symbols]

[0055] 100,200 Energy storage device 12 Exterior body 14 Sealing plate 20 Electrode body 29 Electrode holder 30 Positive terminal 40 Negative terminal 50 Positive electrode current collector 60 Negative electrode current collector 70 Separator 80,280 Shielding part 90 Gasket 91 First insulating member (positive electrode side) 92 First insulating member (negative electrode side) 93 Second insulating member

Claims

1. an electrode body having an electrode tab; An electrolyte; an exterior body having an opening and accommodating the electrode assembly and the electrolyte; a sealing plate that closes the opening, the sealing plate having a liquid injection hole through which the electrolyte is injected into the exterior body; a current collector attached to the sealing plate and electrically connected to the electrode assembly via the electrode tab; A power storage device comprising: An insulating member is provided between the sealing plate and the current collector, the liquid injection hole is provided in the sealing plate so as not to overlap with a portion where the current collector is attached, Here, a shielding portion is provided between the injection hole and the electrode body to prevent the electrolyte injected from the injection hole from directly contacting the electrode body, The insulating member is a main body portion disposed between the sealing plate and the current collector; The shielding portion has a plate shape and extends outward from the main body portion; Equipped with A power storage device, wherein a width of a tip end of the shielding portion is smaller than a width of a base end of the shielding portion.

2. The power storage device according to claim 1 , wherein the shielding portion is inclined toward the electrode body.

3. The power storage device according to claim 2 , wherein a tip of the shielding portion is in contact with an upper end of the electrode body that faces the sealing plate.

4. The shielding portion is It is a substantially rectangular plate-like shape, The electricity storage device according to any one of claims 1 to 3, comprising a straight portion at a tip end and two curved portions at both ends of the straight portion.

5. The power storage device according to any one of claims 1 to 3, wherein the tip is rounded or has a polygonal shape having four or more sides.

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