Energy Storage Devices

Abstract

To provide a power storage device that can increase the electrical insulation between a terminal outer surface of a terminal member and a case outer surface of a case member without increasing the overall size of a resin member.SOLUTION: A power storage device 1 includes: a case member 22; terminal members 40, 50 inserted in insertion holes 22a, 22b of the case member 22; and resin members 60, 70 fixing the terminal members 40, 50 to the case member 22. The resin members 60, 70 include, on resin outer surfaces 60m, 70m exposed on an outer side EH of the case member 22, at least any one of recesses 63, 73 and a projection portion increasing a creepage distance ML from terminal outer surfaces 41m, 51m, which are exposed on the outer side EH of the terminal members 40, 50, to a case outer surface 22m exposed on the outer side EH of the case member 22.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an electricity storage device, such as a battery or a capacitor, in which a terminal member is fixed via a resin member to a case member that forms part of the case. [Background technology]

[0002] As an electricity storage device, a rectangular battery in which positive and negative terminal members are fixed to a rectangular box-shaped case via a resin member is known. Specifically, the case is composed of a bottomed rectangular cylindrical body member having a rectangular annular opening, and a rectangular plate-shaped cover member joined to the body member over the entire circumference in a form that closes the opening. The positive and negative terminal members are inserted into a pair of insertion holes provided in the cover member, respectively, and extend from the inside to the outside of the case. A pair of resin members are joined to the cover member and the terminal members, respectively, while insulating between the cover member and the terminal members, and fix the terminal members to the cover member. For example, Patent Documents 1 and 2 can be cited as related prior art (see, for example, Figures 1 and 2, paragraph (0018) of Patent Document 1, and Figures 1 to 3, paragraph (0080) of Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-272324 A [Patent Document 2] JP 2018-097978 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned battery, it is desirable to improve the electrical insulation between the terminal outer surface exposed outside the cover member (case member) of the terminal member and the case outer surface exposed outside the cover member (case member). This is because there is a risk that the electrical insulation between the terminal outer surface and the case outer surface will decrease due to dust or moisture adhering to the battery. On the other hand, due to various constraints in designing a battery, it may be difficult to increase the overall size of the resin member to improve the electrical insulation between the terminal outer surface and the case outer surface.

[0005] The present invention has been made in consideration of the current situation, and provides an electricity storage device that can improve the electrical insulation between the outer terminal surface of the terminal member and the outer case surface of the case member without increasing the overall size of the resin member. [Means for solving the problem]

[0006] (1) One aspect of the present invention for solving the above problem is an electricity storage device including a case member having an insertion hole, a terminal member inserted into the insertion hole of the case member, and a resin member that is joined to the case member and the terminal member while insulating the case member from the terminal member, and fixes the terminal member to the case member, the terminal member is located outside the case member and has a terminal outer portion including a flat terminal top surface forming an outer terminal surface exposed to the outside, The resin member is a resin outer frame portion that is located on the outside of the case member, that is frame-shaped and surrounds the periphery of the terminal outer portion of the terminal member, and that includes a frame top surface that is flush with the terminal top surface of the terminal outer portion, The above case member the above Exposed resin surface The top surface of the frame To, The above terminal is surrounded by a ring-shaped portion on the top surface of the terminal. A recess for increasing the creepage distance from the outer surface of the terminal to the outer surface of the case exposed to the outside of the case member. Department It is an electricity storage device having the above structure.

[0007] In the above-described electricity storage device, a recess is provided on the resin outer surface of the resin member to increase the creepage distance from the terminal outer surface of the terminal member to the case outer surface of the case member. Department This makes it possible to improve electrical insulation between the outer terminal surface of the terminal member and the outer case surface of the case member without increasing the overall size of the resin member. 。

[0009] In the above-mentioned power storage device, a recess is provided on the frame top surface of the resin outer frame portion of the resin outer surface of the resin member, surrounding the periphery of the terminal top surface. Therefore, unlike when a protrusion is provided on the frame top surface, a part of the resin member does not protrude outward from the terminal top surface, and the creepage distance between the terminal top surface and the case outer surface can be secured without interfering with the connection of the bus bar or the like to the terminal top surface. In addition, the creepage distance between the terminal top surface and the case outer surface can be increased over the entire circumference, thereby increasing the electrical insulation between the terminal top surface and the case outer surface over the entire circumference. The annular recess may be provided in a single layer on the top surface of the frame, or may be provided in two or more layers. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of a battery according to an embodiment. [Diagram 2] 1 is a cross-sectional view of a battery according to an embodiment taken along a battery height direction and a battery width direction. [Diagram 3] FIG. 2 is a partially enlarged top view of the vicinity of a terminal member and a resin member in the battery according to the embodiment. [Figure 4] 6 is a cross-sectional view taken along the line AA in FIGS. 3 and 5, showing the vicinity of a terminal member and a resin member in the battery according to the embodiment. FIG. [Diagram 5] 5 is a cross-sectional view taken along the arrow BB in FIGS. 3 and 4, showing the vicinity of a terminal member and a resin member in the battery according to the embodiment. FIG. [Figure 6] FIG. 4 is a partially enlarged top view of the vicinity of a terminal member and a resin member in a battery according to a reference embodiment. [Figure 7] 9 is a cross-sectional view taken along the line AA in FIGS. 6 and 8 in the vicinity of a terminal member and a resin member in the battery according to the reference embodiment. FIG. [Figure 8] 8 is a cross-sectional view taken along the line BB in FIGS. 6 and 7 in the vicinity of a terminal member and a resin member in a battery according to a reference embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (Implementation state) Hereinafter, the present invention Fruit The embodiment will be described with reference to the drawings. In a nutshell FIG. 2 shows a perspective view of the battery (electricity storage device) 1, and FIG. 3 shows a cross-sectional view of the battery 1. 4 4 and 5 are enlarged top views of the terminal member 0 and the resin member 60. 4 5. In the following description, the battery height direction AH, battery width direction BH, and battery thickness direction CH of battery 1 are defined as the directions shown in Figures 1 to 5. Battery 1 is a square (rectangular parallelepiped) sealed lithium ion secondary battery that is mounted on vehicles such as hybrid cars, plug-in hybrid cars, and electric cars.

[0012] The battery 1 is composed of a case 10, a flat wound electrode assembly 30 housed in the case 10, a positive electrode terminal member 40 and a negative electrode terminal member 50 each supported on a case top 11 (lid member 22) of the case 10, etc. The electrode assembly 30 is covered in the case 10 by a bag-shaped insulating holder 5 made of an insulating film and opening to the upper side AH1 in the battery height direction AH. An electrolyte 3 is also housed in the case 10, a part of which is impregnated in the electrode assembly 30, and the remainder is pooled on the case bottom 12 of the case 10.

[0013] The case 10 is made of metal (in this embodiment). In a state The case 10 is a rectangular box made of aluminum and has a rectangular case upper part 11 located on the upper side AH1 in the battery height direction AH, a rectangular case bottom part 12 facing the upper part 11 and located on the lower side AH2 in the battery height direction AH, and four rectangular case side parts 13, 14, 15, 16 connecting the upper and lower parts. The case 10 is composed of a bottomed, square cylindrical main body member 21 having a rectangular annular opening 21c on the upper side AH1, and a rectangular plate-shaped lid member (case member) 22 laser-welded to the main body member 21 around the entire periphery in a manner that closes the opening 21c.

[0014] The case upper portion 11 (lid member 22) is provided with a safety valve 28 that breaks and opens when the internal pressure of the case 10 exceeds the valve opening pressure. The lid member 22 is also provided with a liquid injection hole 22k that communicates between the inside and outside of the case 10, and is airtightly sealed with a disk-shaped sealing member 29 made of aluminum. Furthermore, rectangular insertion holes 22a, 22b are provided in the lid member 22 near the ends of one side BH1 and the other side BH2 in the battery width direction BH. A positive electrode terminal member 40 made of aluminum is inserted into one insertion hole 22a and is fixed to the lid member 22 in a state insulated from the case 10 via a resin member 60. A negative electrode terminal member 50 made of copper is inserted into the other insertion hole 22b and is fixed to the lid member 22 in a state insulated from the case 10 via a resin member 70.

[0015] These terminal members 40, 50 are each formed by punching out a metal plate (the positive terminal member 40 is an aluminum plate, and the negative terminal member 50 is a copper plate) into a predetermined shape and bending it, and each have a terminal outer portion 41, 51 located on the outside EH of the cover member 22, and a terminal inner portion 42, 52 located mainly inside the case 10 and connected to the terminal outer portion 41, 51 via the insertion holes 22a, 22b. The terminal outer portions 41, 51 are rectangular flat plates, and have terminal top surfaces 41m, 51m that are entirely exposed and have a rectangular flat surface. In this embodiment In a state The terminal top surfaces 41m, 51m form the terminal outer surfaces of the terminal members 40, 50 that are exposed to the outer side EH of the cover member 22. The positive terminal inner portion 42 is joined and electrically connected to a positive current collecting portion 33 (described later) of the electrode body 30 within the case 10. On the other hand, the negative terminal inner portion 52 is joined and electrically connected to a negative current collecting portion 36 (described later) of the electrode body 30 within the case 10.

[0016] Next, the resin members 60, 70 will be described. The positive electrode resin member 60 is bonded to the cover member 22 and the terminal member 40 while insulating the cover member 22 from the terminal member 40, and fixes the terminal member 40 to the cover member 22. The negative electrode resin member 70 is bonded to the cover member 22 and the terminal member 50 while insulating the cover member 22 from the terminal member 50, and fixes the terminal member 50 to the cover member 22.

[0017] These resin members 60, 70 are formed by insert molding in a state where the terminal members 40, 50 are inserted into the insertion holes 22a, 22b of the cover member 22, respectively. The resin members 60, 70 are made of polyphenylene sulfide (PPS) and have a resin outer frame portion 61, 71 located on the outside EH of the cover member 22, and a resin inner portion 62, 72 located inside the case 10 and in the insertion holes 22a, 22b of the cover member 22 and connected to the resin outer frame portion 61, 71. The resin outer frame portion 61, 71 insulates between the terminal outer portion 41, 51 of the terminal members 40, 50 and the cover member 22. On the other hand, the resin inner portion 62, 72 insulates between the terminal inner portion 42, 52 of the terminal members 40, 50 and the cover member 22.

[0018] The resin outer frame portion 61, 71 is a frame surrounding the periphery of the terminal outer portion 41, 51 of the terminal member 40, 50, and has a frame top surface 61ma, 71ma that is flush with the terminal top surface 41m, 51m of the terminal outer portion 41, 51, and a frame side surface 61mb, 71mb that extends from the periphery of the frame top surface 61ma, 71ma to the lower side AH2. In a state The frame top surfaces 61ma, 71ma and the frame side surfaces 61mb, 71mb are the resin members 60, 70. Lid material This corresponds to 60m and 70m of the resin outer surface exposed on the outer EH of 22.

[0019] A rectangular annular recess 63, 73 having a V-shaped cross section is formed in the resin outer surface 60m, 70m of the resin member 60, 70, more specifically, in the frame top surface 61ma, 71ma of the resin outer frame portion 61, 71 of the resin outer surface 60m, 70m. By providing such a recess 63, 73, the creepage distance ML from the terminal top surface 41m, 51m of the terminal member 40, 50 to the lid outer surface (case outer surface) 22m exposed to the outside EH of the lid member 22 is longer than when the recess 63, 73 is not provided.

[0020] Next, the electrode body 30 will be described. The electrode body 30 is formed by stacking a strip-shaped positive electrode plate 31 and a strip-shaped negative electrode plate 34 with a pair of separators 37 in between, each of which is a strip-shaped resin porous film, rolling them up into a cylindrical shape, and then pressing them into a flat shape. The electrode body 30 is housed in the case 10 in a sideways state. The end of the electrode body 30 on one side BH1 in the battery width direction BH is a positive electrode current collector 33 in which the positive electrode current collector foil 32 of the positive electrode plate 31 protrudes in a spiral shape. The positive electrode current collector 33 is joined to the terminal inner part 42 of the positive electrode terminal member 40. The end of the electrode body 30 on the other side BH2 in the battery width direction BH is a negative electrode current collector 36 in which the negative electrode current collector foil 35 of the negative electrode plate 34 protrudes in a spiral shape. The negative electrode current collector 36 is joined to the terminal inner part 52 of the negative electrode terminal member 50.

[0021] As described above, in the battery 1, the resin outer surfaces 60m, 70m of the resin members 60, 70 have the recesses 63, 73 that increase the creepage distance ML from the terminal top surfaces (terminal outer surfaces) 41m, 51m of the terminal members 40, 50 to the lid outer surface 22m of the lid member 22. This makes it possible to increase the electrical insulation between the terminal top surfaces 41m, 51m of the terminal members 40, 50 and the lid outer surface 22m of the lid member 22 without increasing the size of the resin members 60, 70 as a whole.

[0022] Further, in this embodiment In a state In the resin member 60, 70, a ring-shaped recess 63, 73 surrounding the terminal top surface 41m, 51m is provided on a frame top surface 61ma, 71ma of a resin outer frame portion 61, 71 of a resin outer surface 60m, 70m of the resin member 60, 70. For this reason, a protrusion 65, 75 is provided on the frame top surface 61ma, 71ma. Reference form As in the battery 100, a portion of the resin members 60, 70 does not protrude outward EH from the terminal top faces 41m, 51m, and the creepage distance ML between the terminal top faces 41m, 51m and the lid outer surface 22m can be secured without interfering with the connection of the bus bar (not shown) to the terminal top faces 41m, 51m. In addition, the creepage distance ML between the terminal top faces 41m, 51m and the lid outer surface 22m can be lengthened over the entire circumference, thereby increasing the electrical insulation between the terminal top faces 41m, 51m and the lid outer surface 22m over the entire circumference.

[0023] ( Reference form ) Next, Reference form The following will be described with reference to FIGS. 6 to 8. Attitude Description of similar parts will be omitted or simplified. Attitude In the battery 1, recesses 63, 73 for lengthening the creepage distance ML are provided on the frame top surfaces 61ma, 71ma of the resin outer surfaces 60m, 70m of the resin members 60, 70. Reference form The battery 100 is different in that the frame top faces 61ma, 71ma of the resin outer surfaces 60m, 70m of the resin members 60, 70 are provided with protrusions 65, 75 that lengthen the creepage distance ML.

[0024] Specifically, the protrusions 65, 75 are formed in a rectangular ring shape surrounding the periphery of the terminal top surfaces 41m, 51m on the frame top surfaces 61ma, 71ma of the resin outer frame portions 61, 71 of the resin outer surfaces 60m, 70m of the resin members 60, 70. As a result, the creepage distance ML from the terminal top surfaces 41m, 51m of the terminal members 40, 50 to the lid outer surface 22m of the lid member 22 is longer than when the protrusions 65, 75 are not provided.

[0025] In this way, Reference form 1 battery 00 In the present embodiment, the resin outer surfaces 60m, 70m have the protrusions 65, 75 that lengthen the creepage distance ML from the terminal top surfaces 41m, 51m to the lid outer surface 22m, so that the electrical insulation between the terminal top surfaces 41m, 51m and the lid outer surface 22m can be improved without increasing the overall size of the resin members 60, 70. Attitude The similar parts are the same as in the embodiment. Attitude It has the same effect.

[0026] The above is an embodiment of the present invention. In a nutshell Although the present invention has been described above with reference to the embodiment, In a nutshell It goes without saying that the present invention is not limited to the above and can be modified as appropriate without departing from the spirit of the present invention. [Explanation of symbols]

[0027] 1,100 Batteries (energy storage devices) 10 Cases 21 Main body parts 22 Lid member (case member) 22m Lid outer surface (case outer surface) 22a, 22b Insertion holes 30 Electrode body 40,50 Terminal material 41,51 Terminal outer part 41m, 51m Terminal top surface (terminal outer surface) 60,70 Resin material 60m,70m Resin outer surface 61,71 Resin outer frame 61ma,71ma Frame top surface 61mb,71mb Frame side 63,73 Recess 65,75 Convex EH (Outside of cover) ML creepage distance

Claims

[Claim 1] A case member having an insertion hole; a terminal member inserted into the insertion hole of the case member; and a resin member that is bonded to the case member and the terminal member while insulating the case member and the terminal member, and fixes the terminal member to the case member. An electricity storage device, The terminal member is a terminal outer portion that is located outside the case member and includes a flat terminal top surface that forms an outer surface of the terminal exposed to the outside, The resin member is a resin outer frame portion that is located on the outside of the case member, that is frame-shaped and surrounds the periphery of the terminal outer portion of the terminal member, and that includes a frame top surface that is flush with the terminal top surface of the terminal outer portion, The frame top surface of the resin outer surface exposed to the outside of the case member has a ring-shaped recess surrounding the periphery of the terminal top surface, the recess lengthening the creepage distance from the terminal outer surface to the case outer surface exposed to the outside of the case member. Energy storage device.

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