JP7262433B2 - battery - Google Patents

Description

The present technology relates to batteries.

A current interrupting mechanism for interrupting a current path between an external terminal and an electrode body in a battery case is conventionally known. Further, an insulating sheet for ensuring insulation between an electrode body housed in a battery case and the battery case has been conventionally known. These configurations are shown in Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2015-213042) and Patent Document 2 (Japanese Patent No. 6314086).

JP 2015-213042 A Japanese Patent No. 6314086

When attaching the sealing plate to which the current interrupting mechanism is attached to the battery case, the parts of the current interrupting mechanism may come into contact with the electrode assembly, causing the active material to peel off. If the liberated active material comes into contact with the battery case, it may cause corrosion of the battery case.
An object of the present technology is to provide a battery in which peeling of an active material of an electrode body is suppressed.

A battery according to the present technology includes an exterior body including an opening and a side wall defining the opening, a sealing plate that seals the opening, an electrode body housed in the exterior body, and provided between the sealing plate and the electrode body. and an insulating sheet disposed between the exterior body and the electrode body and having a folded portion on a surface of the electrode body facing the current blocking mechanism.

According to the present technology, it is possible to provide a battery in which peeling of the active material of the electrode assembly is suppressed.

1 is a perspective view of a prismatic secondary battery; FIG. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1; FIG. 3 is a plan view of a positive electrode plate that constitutes the electrode body; FIG. 3 is a plan view of a negative electrode plate that constitutes the electrode body; FIG. 2 is a plan view showing an electrode body consisting of a positive electrode plate and a negative electrode plate; FIG. 4 is a diagram showing a connection structure between an electrode body, a positive collector member, and a negative collector member. FIG. 4 is a diagram showing a mounting structure of a positive current collecting member and a negative current collecting member to a sealing plate; FIG. 8 is a cross-sectional view taken along line VII-VII in FIG. 7; FIG. 8 is a cross-sectional view taken along line IX-IX in FIG. 7; It is a figure which shows the state where the sealing board and the electrode body were connected. FIG. 4 is an enlarged view of the vicinity of the positive collector member in a state where the sealing plate and the electrode body are connected; FIG. 4 is an exploded view of an example of an insulating sheet; 1 is an exploded perspective view of a prismatic secondary battery including insulating sheets; FIG. FIG. 4 is a schematic diagram showing the shape of folded portions in the insulating sheet. FIG. 10 is an exploded view of a modification of the insulating sheet; FIG. 10 is a schematic diagram showing a modified shape of the folding portion in the insulating sheet. FIG. 10 is a schematic diagram (Part 1) showing another modified shape of the folding portion in the insulating sheet. FIG. 11 is a schematic diagram (Part 2) showing another modified shape of the folding portion in the insulating sheet. FIG. 10 is a schematic diagram (part 3) showing another modified shape of the folding portion in the insulating sheet; FIG. 10 is a schematic diagram (part 4) showing another modified shape of the folding portion in the insulating sheet. FIG. 10 is a schematic diagram (No. 5) showing another modified shape of the folding portion in the insulating sheet.

Embodiments of the present technology will be described below. In some cases, the same reference numerals are given to the same or corresponding parts, and the description thereof will not be repeated.

In the embodiments described below, when referring to the number, amount, etc., the scope of the present technology is not necessarily limited to the number, amount, etc., unless otherwise specified. Also, in the following embodiments, each component is not necessarily essential for the present technology unless otherwise specified.

In this specification, the descriptions of "comprise," "include," and "have" are open-ended. That is, the inclusion of one configuration does not exclude the inclusion of other configurations.

FIG. 1 is a perspective view of a prismatic secondary battery 1. FIG. FIG. 2 is a cross-sectional view taken along line II--II in FIG.

As shown in FIGS. 1 and 2, the prismatic secondary battery 1 includes a battery case 100, an electrode body 200, an insulating sheet 300, a positive electrode terminal 400, a negative electrode terminal 500, a positive current collecting member 600, and a negative electrode. It includes a collector member 700 , a current interrupting mechanism 800 and a cover member 900 .

The battery case 100 is composed of a bottomed prismatic rectangular outer body 110 having an opening and a sealing plate 120 that seals the opening of the rectangular outer body 110 . Rectangular exterior body 110 and sealing plate 120 are preferably made of metal, preferably aluminum or an aluminum alloy.

The sealing plate 120 is provided with an electrolyte injection hole 121 . After the electrolyte is injected into the battery case 100 through the electrolyte injection hole 121 , the electrolyte injection hole 121 is sealed by the sealing member 122 . For example, blind rivets and other metal members can be used as the sealing member 122 .

A gas exhaust valve 123 is provided on the sealing plate 120 . The gas exhaust valve 123 breaks when the pressure inside the battery case 100 exceeds a predetermined value. As a result, the gas inside the battery case 100 is discharged to the outside of the battery case 100 .

The electrode body 200 is accommodated in the battery case 100 together with the electrolyte. The electrode body 200 is formed by stacking a positive electrode plate and a negative electrode plate with a separator interposed therebetween. An insulating sheet 300 made of resin is arranged between the electrode body 200 and the rectangular outer body 110 .

A positive electrode tab 210A and a negative electrode tab 210B are provided at the end of the electrode body 200 on the side of the sealing plate 120 .

The positive electrode tab 210</b>A and the positive electrode terminal 400 are electrically connected via the positive current collecting member 600 . The positive current collector 600 includes a first positive current collector 610 and a second positive current collector 620 . In addition, the positive electrode current collecting member 600 may be composed of one component. The positive electrode current collecting member 600 is preferably made of metal, and more preferably made of aluminum or an aluminum alloy.

The negative electrode tab 210B and the negative electrode terminal 500 are electrically connected via the negative current collecting member 700 . The negative electrode current collector 700 includes a first negative electrode current collector 710 and a second negative electrode current collector 720 . Note that the negative electrode current collecting member 700 may be composed of one component. The negative electrode current collecting member 700 is preferably made of metal, and more preferably made of copper or a copper alloy.

The positive electrode terminal 400 is fixed to the sealing plate 120 via an external insulating member 410 made of resin. The negative electrode terminal 500 is fixed to the sealing plate 120 via an external insulating member 510 made of resin.

The positive electrode terminal 400 is preferably made of metal, and more preferably made of aluminum or an aluminum alloy. The negative electrode terminal 500 is preferably made of metal, and more preferably made of copper or a copper alloy. Negative electrode terminal 500 may have a region made of copper or a copper alloy located inside battery case 100 and a region made of aluminum or an aluminum alloy located outside battery case 100 .

The current interrupting mechanism 800 is provided in the conductive path between the positive electrode tab 210A (positive electrode plate) and the positive electrode terminal 400 . The current interrupting mechanism 800 operates when the pressure inside the battery case 100 reaches or exceeds a predetermined value, and can interrupt the conductive path. The operating pressure of gas exhaust valve 123 is set to a value higher than the operating pressure of current interrupting mechanism 800 . The current interrupting mechanism 800 can also be provided in the conductive path between the negative electrode tab 210B and the negative electrode terminal 500. FIG.

FIG. 3 is a plan view of a positive electrode plate 200A that constitutes the electrode assembly 200. FIG. The positive electrode plate 200A includes a positive electrode active material (for example, lithium-nickel-cobalt-manganese composite oxide, etc.), a binder (polyvinylidene fluoride (PVdF), etc.), and a conductive material ( For example, it has a main body portion 220A on which a positive electrode active material mixture layer containing a carbon material or the like is formed. A positive electrode core protrudes from the edge of the main body, and the protruding positive electrode core constitutes the positive electrode tab 210A. A positive electrode protective layer 230A containing alumina particles, a binder, and a conductive material is provided on a portion of the positive electrode tab 210A adjacent to the body portion 220A. The positive electrode protective layer 230A has an electrical resistance greater than that of the positive electrode active material mixture layer. The positive electrode active material mixture layer does not have to contain a conductive material. The positive electrode protective layer 230A does not necessarily have to be provided.

FIG. 4 is a plan view of the negative electrode plate 200B that constitutes the electrode assembly 200. FIG. The negative electrode plate 200B has a main body portion 220B in which negative electrode active material layers are formed on both sides of a negative electrode core made of rectangular copper foil. A negative electrode core protrudes from an end side of the main body portion 220B, and the protruding negative electrode core constitutes the negative electrode tab 210B.

FIG. 5 is a plan view showing an electrode assembly 200 consisting of a positive electrode plate 200A and a negative electrode plate 200B. As shown in FIG. 5, the electrode body 200 is manufactured so that the positive tabs 210A of each positive plate 200A are laminated at one end, and the negative tabs 210B of each negative plate 200B are laminated. The positive electrode plates 200A and the negative electrode plates 200B are stacked, for example, by about 50 sheets each. The positive electrode plates 200A and the negative electrode plates 200B are alternately laminated with rectangular separators made of polyolefin interposed therebetween. Note that a long separator may be zigzagged and used.

FIG. 6 is a diagram showing a connection structure between the electrode assembly 200 and the positive current collecting member 600 and the negative current collecting member 700. As shown in FIG. As shown in FIG. 6, the electrode body 200 is composed of a first electrode body element 201 (first lamination group) and a second electrode body element 202 (second lamination group). Separators are also disposed on the outer surfaces of the first electrode element 201 and the second electrode element 202, respectively. The first electrode body element 201 and the second electrode body element 202 can be fixed in a layered state by, for example, tape or the like. Alternatively, an adhesive layer may be provided on each of the positive electrode plate 200A, the negative electrode plate 200B, and the separator so that the separator and the positive electrode plate 200A are adhered to each other, and the separator and the negative electrode plate 200B are adhered to each other.

A plurality of positive electrode tabs 210A of the first electrode body element 201 constitute a first positive electrode tab group 211A. A plurality of negative electrode tabs 210B of the first electrode element 201 constitute a first negative electrode tab group 211B. A plurality of positive electrode tabs 210A of the second electrode body element 202 constitute a second positive electrode tab group 212A. A plurality of negative electrode tabs 210B of the second electrode element 202 constitute a second negative electrode tab group 212B.

A second positive current collector 620 and a second negative current collector 720 are arranged between the first electrode body element 201 and the second electrode body element 202 . The second positive electrode current collector 620 has a first opening 620A and a second opening 620B. The first positive electrode tab group 211A and the second positive electrode tab group 212A are welded onto the second positive electrode current collector 620 to form the weld connection portion 213 . The first negative electrode tab group 211B and the second negative electrode tab group 212B are welded onto the second negative electrode current collector 720 to form the weld connection portion 213 . Weld connection 213 may be formed, for example, by ultrasonic welding, resistance welding, laser welding, or the like.

7A and 7B are diagrams showing a mounting structure of the positive collector member 600 and the negative collector member 700 to the sealing plate 120. FIG. FIG. 8 shows a VII-VII section in FIG. FIG. 9 shows the IX-IX section in FIG.

First, with reference to FIGS. 7 and 8, the attachment of the positive collector member 600 to the sealing plate 120 will be described.

An external insulating member 410 made of resin is arranged on the outer surface side of the sealing plate 120 . An insulating member 420 and a conductive member 430 made of resin are arranged on the inner surface side of the sealing plate 120 . After that, the positive electrode terminal 400 is inserted into the through hole of the external insulating member 410 , the positive electrode terminal mounting hole of the sealing plate 120 , the through hole of the insulating member 420 , and the through hole of the conductive member 430 . Then, the tip of the positive electrode terminal 400 is caulked onto the conductive member 430 . Thereby, the positive electrode terminal 400, the external insulating member 410, the sealing plate 120, the insulating member 420, and the conductive member 430 are fixed. The caulking-connected portions of positive electrode terminal 400 and conductive member 430 are preferably welded by laser welding or the like.

The conductive member 430 has a conductive member base portion 431 and a tubular portion 432 extending from the edge portion of the conductive member base portion 431 toward the electrode body 200 (lower side in the drawing). An opening 433 is provided at the end of the tubular portion 432 on the electrode body 200 side.

The deformation plate 440 is arranged so as to close the opening 433 of the conductive member 430 . A peripheral edge of the deformation plate 440 is welded to the conductive member 430 by laser welding or the like. Thereby, the opening 433 of the conductive member 430 is sealed by the deformation plate 440 . The conductive member 430 and the deformation plate 440 are preferably made of metal, and more preferably aluminum or an aluminum alloy.

A protrusion provided on a resin insulating member 630 (positive electrode current collector holder) is inserted into a through-hole provided in the first positive electrode current collector 610, and the tip of the protrusion is expanded in diameter by heat caulking or the like. Thus, a connection portion 631 is formed, and the first positive electrode current collector 610 and the insulating member 630 can be connected. Further, by inserting the projection provided on the insulating member 630 into the through hole provided on the first positive electrode current collector 610, the displacement preventing portion 632 can be formed.

The insulating member 630 connected to the first positive current collector 610 and the insulating member 420 on the side of the positive electrode terminal 400 are connected by fitting. Note that the insulating member 630 may be provided with a claw portion, and the claw portion may be hooked to the insulating member 420 for connection.

After that, in the opening provided in the insulating member 630, the first positive electrode current collector 610 on the side of the positive electrode current collecting member 600 and the central portion of the deformation plate 440 on the side of the positive electrode terminal 400 are connected by laser welding or the like. . It is preferable to provide a connection hole in the first positive electrode current collector 610 and weld the edge of the connection hole to the deformation plate 440 .

As shown in FIG. 8, the insulating member 630 has a tubular portion 630A protruding toward the electrode body 200 side. Cylindrical portion 630A penetrates second opening 620B of second positive electrode current collector 620 and defines hole portion 630B communicating with electrolyte injection hole 121 .

When attaching the positive electrode current collector 600 to the sealing plate 120 , first, the first positive electrode current collector 610 is connected to the insulating member 630 on the sealing plate 120 . Subsequently, the second positive current collector 620 connected to the electrode assembly 200 is attached to the first positive current collector 610 . At this time, the second positive current collector 620 is arranged on the insulating member 630 such that the second positive current collector 620 partially overlaps the first positive current collector 610 . Subsequently, the periphery of the first opening 620A provided in the second positive electrode current collector 620 is weld-connected to the first positive electrode current collector 610 by laser welding or the like.

Next, attachment of the negative electrode current collecting member 700 to the sealing plate 120 will be described with reference to FIGS. 7 and 9. FIG.

An external insulating member 510 made of resin is arranged on the outer surface side of the sealing plate 120 . A first negative electrode current collector 710 and a resin insulating member 730 (negative electrode current collector holder) are arranged on the inner surface side of the sealing plate 120 . Next, the negative terminal 500 is inserted into the through hole of the external insulating member 510 , the negative terminal mounting hole of the sealing plate 120 , the through hole of the first negative current collector 710 , and the through hole of the insulating member 730 . Then, the tip of the negative terminal 500 is crimped onto the first negative current collector 710 . Thereby, the negative electrode terminal 500, the external insulating member 510, the sealing plate 120, the first negative electrode current collector 710, and the insulating member 730 are fixed. It should be noted that the caulking-connected portions of the negative electrode terminal 500 and the first negative electrode current collector 710 are preferably weld-connected by laser welding or the like.

Furthermore, the second negative electrode current collector 720 is arranged on the insulating member 730 such that a portion of the second negative electrode current collector 720 overlaps with the first negative electrode current collector 710 . The second negative electrode current collector 720 is welded to the first negative electrode current collector 710 by laser welding or the like at the first opening 720A provided in the second negative electrode current collector 720 .

When attaching the negative electrode current collector 700 to the sealing plate 120 , first, the first negative electrode current collector 710 is connected to the insulating member 730 on the sealing plate 120 . Subsequently, the second negative current collector 720 connected to the electrode body 200 is attached to the first negative current collector 710 . At this time, the second negative current collector 720 is arranged on the insulating member 730 such that the second negative current collector 720 partially overlaps the first negative current collector 710 . Subsequently, the periphery of the first opening 720A provided in the second negative electrode current collector 720 is welded to the first negative electrode current collector 710 by laser welding or the like.

The operation of the current interrupting mechanism 800 shown in FIG. 8 will be described. As the pressure in the battery case 100 increases, the central portion of the deformation plate 440 deforms to move toward the sealing plate 120 . When the pressure inside the battery case 100 reaches or exceeds a predetermined value, the deformable plate 440 is deformed, and the fragile portion provided in the first positive electrode current collector 610 is broken. Thereby, the conductive path from the positive electrode plate 200A to the positive electrode terminal 400 is cut off. As the fragile portion, it is preferable to provide, for example, an annular notch portion provided so as to surround the connecting portion with the deformation plate 440 in the first positive electrode current collector 610 .

When the prismatic secondary battery 1 becomes overcharged and the pressure in the battery case 100 rises, the current interrupting mechanism 800 operates to cut off the conductive path from the positive electrode plate 200A to the positive electrode terminal 400, thereby further overcharging. Charging progress is prevented.

A through hole 400A is formed in the positive electrode terminal 400 . By sending gas into the inside of the conductive member 430 through the through hole 400A, a leak test can be performed on the weld connection between the conductive member 430 and the deformation plate 440. FIG. The through hole 400A is sealed with a terminal sealing member made of resin or metal.

FIG. 10 is a diagram showing a state in which the sealing plate 120 and the electrode body 200 are connected. FIG. 11 is an enlarged view of the positive collector member 600 and its surroundings when the sealing plate 120 and the electrode body 200 are connected.

As described with reference to FIGS. 7 to 9, the first electrode element 201 and the second electrode element 202 are attached to the sealing plate 120 with the positive collector member 600 and the negative collector member 700 interposed therebetween. Thereby, as shown in FIG. 10, the first electrode body element 201 and the second electrode body element 202 are connected to the sealing plate 120, and the electrode body 200 is electrically connected to the positive electrode terminal 400 and the negative electrode terminal 500. .

As shown in FIG. 11 , a cover member 900 made of resin is provided on the first positive electrode current collector 610 . The cover member 900 is positioned between the first positive current collector 610 and the electrode body 200 . The cover member 900 may be provided on the negative electrode current collector side. Also, the cover member 900 is not an essential member and can be omitted as appropriate.

From the state shown in FIG. 11, the first electrode body element 201 and the second electrode body element 202 are combined into one. At this time, the first positive electrode tab group 211A and the second positive electrode tab group 212A are bent in different directions. The first negative electrode tab group 211B and the second negative electrode tab group 212B are curved in different directions.

The first electrode body element 201 and the second electrode body element 202 can be put together by tape or the like. Alternatively, the first electrode body element 201 and the second electrode body element 202 can be integrated by arranging them in an insulating sheet molded into a box-like or bag-like shape. Furthermore, the first electrode body element 201 and the second electrode body element 202 can be fixed by adhesion.

The first electrode body element 201 and the second electrode body element 202 combined into one are wrapped with an insulating sheet and inserted into the rectangular outer body 110 . After that, the sealing plate 120 is welded to the rectangular outer body 110 and the opening of the rectangular outer body 110 is sealed with the sealing plate 120 to form the sealed battery case 100 .

After that, a non-aqueous electrolyte is injected into the battery case 100 through an electrolyte injection hole 121 provided in the sealing plate 120 . The non-aqueous electrolyte is, for example, a non-aqueous solvent obtained by mixing ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) at a volume ratio (25° C.) of 30:30:40. In addition, LiPF ₆ dissolved at a concentration of 1.2 mol/L can be used.

After the non-aqueous electrolyte is injected, the electrolyte injection hole 121 is sealed with a sealing member 122 . The prismatic secondary battery 1 is completed by performing the above steps.

FIG. 12 is an exploded view of an example of the insulating sheet 300. As shown in FIG. The insulating sheet 300A shown in FIG. Includes bottom region 90A.

First area 10A, second area 20A, and seventh area 70A are arranged to overlap between one short side surface of rectangular exterior body 110 and electrode body 200 . Third region 30A, fourth region 40A, and eighth region 80A are arranged to overlap between the other short side surface of rectangular exterior body 110 and electrode body 200 . The fifth region 50A and the sixth region 60A are arranged between the long side surface of the square exterior body 110 and the electrode body 200. As shown in FIG. Bottom region 90</b>A is arranged between the bottom surface of rectangular outer body 110 and electrode body 200 .

The insulating sheet 300A has folded portions 310A (tongue portions) in portions of the fifth region 50A and the sixth region 60A. The folded portion 310A is folded toward the inside of the rectangular exterior body 110 . Insulation sheet 300A may be made easier to bend by providing a perforation or a thin portion at the base of folded portion 310A.

FIG. 13 is an exploded perspective view of prismatic secondary battery 1 including insulating sheet 300A shown in FIG. FIG. 14 is a schematic diagram showing the shape of the folded portion 310A in the insulating sheet 300A. As shown in FIG. 13 , folded portion 310A is folded so as to cover the upper surface of electrode body 200 facing current interrupting mechanism 800 . Folded portion 310A may be formed at least in a portion facing current interrupting mechanism 800, and may be formed in a wider range.

In this way, the folding portion 310A of the insulating sheet 300A covers the upper surface of the electrode body 200 (the portion facing the current interrupting mechanism 800), so that when the sealing plate 120 with the current interrupting mechanism 800 attached is attached to the square exterior body 110, In addition, it is possible to prevent the active materials on the positive electrode plate 200A and the negative electrode plate 200B from peeling off due to the current interrupting mechanism 800 coming into contact with the electrode assembly 200 . Furthermore, even if the active materials on the positive electrode plate 200A and the negative electrode plate 200B are peeled off, since the upper surface of the electrode assembly 200 facing the current interrupting mechanism 800 is covered with the folded portion 310A of the insulating sheet 300A, the separated active material is removed. It is possible to prevent substances from adhering to the square exterior body 110 . As a result, corrosion of the rectangular exterior body 110 is suppressed.

FIG. 15 is a developed view of an insulating sheet 300B according to a modification. FIG. 16 is a schematic diagram showing the shape of the folded portion 310B in the insulating sheet 300B.

As shown in FIG. 15, the insulating sheet 300B includes a first area 10B, a second area 20B, a third area 30B, a fourth area 40B, a fifth area 50B, a sixth area 60B, a seventh area 70B, and an eighth area. 80B, and bottom region 90B.

First region 10B, second region 20B, and seventh region 70B are arranged to overlap between one short side surface of rectangular exterior body 110 and electrode body 200 . Third region 30B, fourth region 40B, and eighth region 80B are arranged to overlap between the other short side surface of rectangular exterior body 110 and electrode assembly 200 . The fifth region 50B and the sixth region 60B are arranged between the long side surface of the rectangular outer body 110 and the electrode body 200. As shown in FIG. Bottom region 90B is arranged between the bottom surface of square exterior body 110 and electrode body 200 .

The insulating sheet 300B has a folded portion 310B (tongue portion) in a portion of the fifth region 50B. Like folded portion 310A, folded portion 310B is folded so as to cover the upper surface of electrode body 200 facing current interrupting mechanism 800 . However, while the folded portion 310A is folded toward the center from both sides of the electrode body 200, the folded portion 310B extends from one long side surface (first outer surface) of the electrode body 200 to the other long side surface (second outer surface). folded from one side to reach the Since the insulating sheet 300B shown in FIGS. 15 and 16 has one folding portion 310B, the step of providing the insulating sheet 300B is easier than in the case of the insulating sheet 300A.

17 to 21 show shapes of insulating sheets 300C, 300D, 300E, 300F, and 300G according to still other modifications. Shapes of folding portions 310C, 310D, 310E, 310F, and 310G according to modifications will be described with reference to FIGS. 17 to 21. FIG.

In the insulating sheet 300C shown in FIG. 17, the tip of the folded portion 310C is sandwiched between the first electrode element 201 and the second electrode element 202. As shown in FIG. By doing so, there is no need to fix the folded portion 310C using other fixing means such as tape. Moreover, a gap is formed between the first electrode body element 201 and the second electrode body element 202, and penetration of the electrolytic solution into the electrode body 200 is promoted through this gap.

In insulating sheet 300D shown in FIG. 18, folded portion 310D is turned from one side of electrode body 200 and folded onto the opposite long side of electrode body 200. Insulating sheet 300D shown in FIG. Also in the example of FIG. 18, there is no need to fix the folded portion 310D using other fixing means such as tape. Also, compared to the example of FIG. 17, the step of providing the insulating sheet 300D is easier.

In the insulating sheets 300E, 300F, 300G shown in FIGS. 19 to 21, the folded portions 310E, 310F, 310G are folded inward at angles larger than 90°. By doing so, the portion in contact with the current interrupting mechanism 800 can have shock absorbing properties (cushioning properties).

In insulating sheet 300E shown in FIG. 19, folded portions 310E are folded from both sides of electrode body 200 toward the center.

In the insulating sheet 300F shown in FIG. 20, the tip of the folded portion 310F is sandwiched between the first electrode element 201 and the second electrode element 202. As shown in FIG. Folded portion 310</b>F is inclined in a direction away from sealing plate 120 toward the gap between first electrode element 201 and second electrode element 202 . This makes it easier for the electrolyte injected from the electrolyte injection hole 121 to flow into the gap between the first electrode element 201 and the second electrode element 202 .

In the insulating sheet 300G shown in FIG. 21, the folded portion 310G is turned from one side of the electrode assembly 200 and folded onto the opposite long side of the electrode assembly 200. As shown in FIG.

Polypropylene is preferably used as the material constituting the insulating sheet 300, but other than polypropylene, for example, polyethylene, polyphenylene sulfide, polyether ether ketone, nylon, or PET (polyethylene terephthalate) can be used. is.

The thickness of the insulating sheet 300 is preferably about 80 μm to 500 μm, more preferably about 100 μm to 300 μm, and even more preferably about 100 μm to 200 μm.

Although the embodiments of the present technology have been described above, the embodiments disclosed this time should be considered as examples and not restrictive in all respects. The scope of the present technology is indicated by the scope of claims, and is intended to include all modifications within the meaning and scope of equivalence to the scope of the claims.

1 prismatic secondary battery, 10A, 10B first region, 20A, 20B second region, 30A, 30B third region, 40A, 40B fourth region, 50A, 50B fifth region, 60A, 60B sixth region, 70A, 70B seventh region, 80A, 80B eighth region, 90A, 90B bottom region, 100 battery case, 110 prismatic exterior body, 120 sealing plate, 121 electrolyte injection hole, 122 sealing member, 123 gas discharge valve, 200 electrode 200A positive electrode plate 200B negative electrode plate 201 first electrode body element 202 second electrode body element 210A positive electrode tab 210B negative electrode tab 211A first positive electrode tab group 211B first negative electrode tab group 212A second positive electrode Tab group 212B Second negative electrode tab group 213 Welded connection portion 220A, 220B Body portion 230A Positive electrode protective layer 300, 300A, 300B, 300C, 300D, 300E, 300F, 300G Insulating sheet 310A, 310B, 310C, 310D, 310E, 310F, 310G folded portion 400 positive electrode terminal 400A through hole 410,510 external side insulating member 420,630,730 insulating member 430 conductive member 431 conductive member base portion 432 tubular portion 433 opening Part 440 Deformation plate 500 Negative electrode terminal 600 Positive electrode collector 610 First positive collector 620 Second positive collector 620A First opening 620B Second opening 630A Cylindrical part 630B Hole , 631 connection portion, 632 misalignment prevention portion, 700 negative electrode current collector, 710 first negative electrode current collector, 720 second negative electrode current collector, 720A first opening, 800 current interrupting mechanism, 900 cover member.

Claims (7)

an exterior including an opening and sidewalls defining the opening;
a sealing plate that seals the opening;
an electrode body housed in the exterior body;
a current interrupting mechanism provided between the sealing plate and the electrode body;
an insulating sheet disposed between the exterior body and the electrode body and having a folded portion on a surface of the electrode body facing the current interrupting mechanism;
the electrode body includes a first electrode body element and a second electrode body element;
The battery, wherein the folded portion of the insulating sheet has a leading end sandwiched between the first electrode element and the second electrode element. an exterior including an opening and sidewalls defining the opening;
a sealing plate that seals the opening;
an electrode body housed in the exterior body;
a current interrupting mechanism provided between the sealing plate and the electrode body;
an insulating sheet disposed between the exterior body and the electrode body and having a folded portion on a surface of the electrode body facing the current interrupting mechanism;
the electrode body includes a first electrode body element and a second electrode body element;
A gap is formed between the first electrode body element and the second electrode body element,
The battery, wherein the insulating sheet has a portion inclined in a direction away from the sealing plate toward the gap. an exterior including an opening and sidewalls defining the opening;
a sealing plate that seals the opening;
an electrode body housed in the exterior body;
a current interrupting mechanism provided between the sealing plate and the electrode body;
an insulating sheet disposed between the exterior body and the electrode body and having a folded portion on a surface of the electrode body facing the current interrupting mechanism;
the electrode body includes a first outer surface and a second outer surface facing each other;
The battery, wherein the folded portion of the insulating sheet reaches from the first outer surface to the second outer surface. A gap is formed between the first electrode body element and the second electrode body element,
2. The battery according to claim 1 , wherein said insulating sheet has a portion inclined in a direction away from said sealing plate toward said gap. the electrode body includes a first outer surface and a second outer surface facing each other;
5. The battery according to any one of claims 1, 2 and 4, wherein said folded portion of said insulating sheet reaches from said first outer surface to said second outer surface. 4. The battery of claim 3, wherein the electrode body comprises a first electrode body element and a second electrode body element. 7. The battery according to any one of claims 1 to 6, wherein said folded portion of said insulating sheet is folded at an angle greater than 90[deg.].

Images