Secondary battery

Abstract

To prevent an electrolyte from leaking to the outside of an insulation film.SOLUTION: A battery cell 10 comprises: a wound body 50; a case 12 which has an opening part 12A so as to house the wound body 50 together with an electrolyte U; a lid body 21 which closes the opening part 12A and has an inlet 21A for the electrolyte U; first insulation members 34, 44 which are disposed between the lid body 21 and terminal parts 30A, 40A connected to the wound body 50; and an insulation film 60, covering the wound body 50 in all directions and partially covering the terminal part 30A, 40A, which has a first opening 81 where the terminal parts 30A, 40A are penetratingly disposed, and whose edge part forming the first opening 81 is bonded to the first insulation members 34, 44.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a secondary battery.

Background Art

[0002] In a secondary battery, it is known to arrange an insulating film between an electrode body and a battery case to insulate the electrode body from the battery case (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a technique including an insulating bag formed of an insulating resin material that is formed in a bag shape and houses an electrode body, and the insulating bag and the inner wall surface of the case are thermally welded. Thereby, movement of the electrode body in the case can be suppressed.

[0004] By the way, in a secondary battery, it is preferable to suppress leakage of an electrolytic solution to the outside of the insulating film.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In consideration of the above facts, an object of the present invention is to provide a secondary battery that suppresses leakage of an electrolytic solution to the outside of an insulating film.

Means for Solving the Problems

[0007] The secondary battery according to the first aspect of the present invention includes an electrode body, a case having an opening and housing the electrode body together with an electrolytic solution, a lid body that closes the opening and forms an injection port for the electrolytic solution, an insulating member disposed between the lid body and a terminal portion connected to the electrode body, and an insulating film that covers the entire surface of the electrode body and a part of the terminal portion and has a first opening through which the terminal portion is disposed, wherein an edge portion forming the first opening is joined to the insulating member.

[0008] In the secondary battery according to the second aspect of the present invention, which is the secondary battery according to the first aspect of the present invention, the insulating film has a second opening at a position corresponding to the injection port.

[0009] In the secondary battery according to the third aspect of the present invention, which is the secondary battery according to the second aspect of the present invention, the first opening and the second opening are formed by slits extending in the vertical direction at the upper end of the insulating film.

[0010] In the secondary battery according to the fourth aspect of the present invention, which is the secondary battery according to the third aspect of the present invention, the slit includes a first slit forming the first opening and a second slit forming the second opening, and the first slit and the second slit are formed to have the same length.

[0011] In the secondary battery according to the fifth aspect of the present invention, which is the secondary battery according to any one of the first to fourth aspects of the present invention, the insulating film is formed in a bag shape by joining the ends of the insulating film to each other.

Effect of the Invention

[0012] In the secondary battery according to the first aspect of the present invention, since it includes an insulating film that covers the entire surface of the electrode body and a part of the terminal portion and has a first opening through which the terminal portion is disposed, and an edge portion forming the first opening is joined to the insulating member, substantially the entire surface of the electrode body is covered while the first opening is blocked by the insulating member. Therefore, leakage of the electrolytic solution to the outside of the insulating film can be suppressed.

[0013] In the secondary battery according to the second aspect of the present invention, the insulating film is provided with a second opening at a position corresponding to the injection port, so that an opening for injecting the electrolytic solution into the insulating film is formed. Therefore, while suppressing the leakage of the electrolytic solution to the outside of the insulating film, the electrolytic solution can be appropriately injected into the insulating film formed in a bag shape.

[0014] In the secondary battery according to the third aspect of the present invention, the first opening and the second opening are formed by slits extending in the vertical direction at the upper end of the insulating film. Thus, when the upper end of the insulating film is bent, the upper surface of the electrode body is covered with the insulating film. Also, the first opening and the second opening are formed by the portion of the upper end of the insulating film that is not bent. Therefore, a bag-shaped insulating film having the first opening and the second opening can be formed with a simple configuration.

[0015] In the secondary battery according to the fourth aspect of the present invention, the first slit is formed to have the same length as the second slit. Thus, when the upper end of the insulating film between the first slit and the second slit is bent, the upper surface of the electrode body is covered with the insulating film. Also, the first opening and the second opening are formed by the portion of the upper end of the insulating film that is not bent. Therefore, a bag-shaped insulating film having the first opening and the second opening can be formed with a simple configuration.

[0016] In the secondary battery according to the fifth aspect of the present invention, the insulating film is formed in a bag shape by joining the ends of the insulating film to each other. Therefore, the insulating film is formed in a bag shape with a simple configuration. Thus, leakage of the electrolytic solution to the outside of the insulating film can be suppressed with a simple configuration.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0018] Hereinafter, a secondary battery according to an embodiment will be described with reference to the drawings. The secondary battery according to the embodiment is, for example, a lithium ion secondary battery used as an in-vehicle power source for an electric vehicle, a hybrid vehicle, or the like. In each figure, the arrow UP indicates the upper side in the vertical direction of the secondary battery, the arrow FR indicates the front side in the front-rear direction of the secondary battery, and the arrow LH indicates the left side in the left-right direction of the secondary battery. Further, the direction from the front side of the wound body 50 through the bottom to the rear side is defined as the front-rear direction L, and the direction orthogonal to the front-rear direction L is defined as the width direction W.

[0019] [Configuration of Battery Cell 10] As shown in FIG. 1, the battery cell 10 as a secondary battery includes a lid assembly 20, a wound body (an example of an electrode body) 50, an insulating film 60, and a case 12.

[0020] (Lid Assembly 20) The lid assembly 20 includes a lid body 21, a negative electrode current collecting portion 30, and a positive electrode current collecting portion 40.

[0021] 〈Lid Body 21〉 The lid body 21 is made of a metal material (for example, aluminum), and is formed in a rectangular plate shape extending in the left-right direction with the vertical direction as the plate thickness direction. The lid body 21 is provided with an injection port 21A, a safety valve 21B, and a through hole 21C. A cap 28 for closing the injection port 21A is attached to the injection port 21A. The through hole 21C is formed to penetrate each of the negative electrode and the positive electrode in the plate thickness direction.

[0022] 〈Negative Electrode Current Collecting Portion 30〉 The negative electrode current collecting portion 30 includes a negative electrode current collecting terminal 32 as a terminal portion 30A, a first insulating member 34 as an insulating member, a second insulating member 36 as an insulating member, and a negative electrode external terminal 38 as a terminal portion 30A.

[0023] The negative electrode current collector terminal 32 is formed of a metal material (for example, copper), and includes a base portion 32A and an extending portion 32B. The base portion 32A is formed in a rectangular plate shape with the vertical direction as the plate thickness direction, and a through hole 32C penetrating in the plate thickness direction is formed. The extending portion 32B extends downward from the base portion 32A and is formed in a substantially rectangular plate shape with the front-rear direction as the plate thickness direction.

[0024] The first insulating member 34 is formed of an insulating material such as resin. The first insulating member 34 is formed in a rectangular plate shape with the vertical direction as the plate thickness direction, and a through hole 34C penetrating in the plate thickness direction is formed. The first insulating member 34 is interposed between the negative electrode current collector terminal 32 and the lid body 21, and insulates the negative electrode current collector terminal 32 and the lid body 21.

[0025] The second insulating member 36 is formed of an insulating material such as resin. The second insulating member 36 is formed in a rectangular plate shape with the vertical direction as the plate thickness direction, and a through hole 36C penetrating in the plate thickness direction is formed. The second insulating member 36 is interposed between the negative electrode external terminal 38 and the lid body 21, and insulates the negative electrode external terminal 38 and the lid body 21.

[0026] The negative electrode external terminal 38 is formed of a metal material (for example, aluminum), and includes a main body portion 38A and a convex portion 38B. The main body portion 38A is formed in a rectangular plate shape with the vertical direction as the plate thickness direction. The convex portion 38B is formed in a substantially columnar shape extending downward from the main body portion 38A.

[0027] The convex portion 38B is inserted and disposed in the through hole 36C of the second insulating member 36, the through hole 21C of the lid body 21, the through hole 34C of the first insulating member 34, and the through hole 32C of the negative electrode current collector terminal 32, and the tip thereof is caulked. Thereby, the conductivity between the negative electrode current collector terminal 32 and the negative electrode external terminal 38 is ensured.

[0028] 〈Positive electrode current collector portion 40〉 The positive electrode current collector part 40 has the same configuration except for the different materials, and includes a positive electrode current collector terminal 42 as a terminal part 40A, a first insulating member 44 (see FIG. 4) as an insulating member, a second insulating member 46 as an insulating member, and a positive electrode external terminal 48 as a terminal part 40A. The positive electrode current collector terminal 42 is formed of a metal material (for example, aluminum), the positive electrode external terminal 48 is formed of a metal material (for example, aluminum), and the first insulating member 44 and the second insulating member 46 are formed of an insulating material such as resin.

[0029] (Wound body 50) As shown in FIG. 1, the wound body 50 is wound in a state where a negative electrode sheet (not shown), a positive electrode sheet (not shown), and two separators (not shown) are laminated, and is formed in a flat shape.

[0030] The wound body 50 includes a power generation part 51, a negative electrode current collector part 52, and a positive electrode current collector part 53.

[0031] The power generation part 51 has a function of accumulating the electrical energy of the battery cell 10, in which a region of the positive electrode sheet on which an active material layer is formed, a region of the negative electrode sheet on which an active material layer is formed, and a separator are laminated.

[0032] The negative electrode current collector part 52 is crushed and foil-collected in a state where regions of the negative electrode sheet on which no active material layer is formed are laminated. A negative electrode current collector terminal 32 is connected to the negative electrode current collector part 52. The positive electrode current collector part 53 is crushed and foil-collected in a state where regions of the negative electrode sheet on which no active material layer is formed are laminated. A positive electrode current collector terminal 42 is connected to the positive electrode current collector part 53.

[0033] (Insulating film 60) As shown in FIG. 1, the insulating film 60 is formed in a film shape of a material having insulating properties, and ensures the insulation between the wound body 50 and the case 12. As shown in FIG. 3, the insulating film 60 is formed in a bag shape by folding a single film so as to surround the entire wound body 50.

[0034] As shown in FIG. 2, the insulating film 60 includes a bottom surface 61, a front surface 62, a rear surface 63, a front side surface 64, and a rear side surface 65.

[0035] 〈Bottom surface 61〉 The bottom surface 61 is formed in a rectangle at the center of the insulating film in the front-rear direction L and covers the bottom of the wound body 50.

[0036] 〈Front surface 62〉 The front surface 62 is formed in a rectangle continuous with the front side of the bottom surface 61 in the front-rear direction L and is bent to cover the front part of the wound body 50. At the front edge on the front side of the front surface 62 in the front-rear direction L, a first slit 71 and a second slit 72 are formed.

[0037] The first slit 71 is provided at a position corresponding to the negative electrode current collector 30 and the positive electrode current collector 40, and includes a positive electrode side first slit 71A formed on the other side in the width direction W of the front surface 62 and a negative electrode side first slit 71B formed on one side in the width direction W of the front surface 62. The second slit 72 is provided at a position corresponding to the injection port 21A, and includes a positive electrode side second slit 72A formed on the other side in the width direction W of the front surface 62 and a negative electrode side second slit 72B formed on one side in the width direction W of the front surface 62.

[0038] The positive electrode side first slit 71A, the negative electrode side first slit 71B, the positive electrode side second slit 72A, and the negative electrode side second slit 72B are formed to extend the same length in the front-rear direction L.

[0039] The front surface 62 is formed with a first front edge 62A, a second front edge 62B, a third front edge 62C, a fourth front edge 62D, and a fifth front edge 62E by the first slit 71 and the second slit 72.

[0040] The first front edge 62A is formed between the front side surface 64 and the positive electrode side first slit 71A. The second front edge 62B is formed between the positive electrode side first slit 71A and the positive electrode side second slit 72A. The third front edge 62C is formed between the positive electrode side second slit 72A and the negative electrode side second slit 72B. The fourth front edge 62D is formed between the negative electrode side second slit 72B and the negative electrode side first slit 71B. The fifth front edge 62E is formed between the negative electrode side first slit 71B and the front side surface 64.

[0041] The length of the first front edge 62A in the width direction W is made substantially the same as the length of the first insulating member 44 (see FIG. 3) in the width direction W. The length of the fifth front edge 62E in the width direction W is made substantially the same as the length of the first insulating member 34 (see FIG. 3) in the width direction W. The length of the third front edge 62C in the width direction W is made substantially the same as the length of the injection port 21A (see FIG. 1) in the width direction W.

[0042] The second front edge 62B and the fourth front edge 62D are bent to cover the upper part of the front side of the wound body 50.

[0043] 〈Rear surface 63〉 The rear surface 63 is formed as a rectangle continuous with the rear side in the front-rear direction L of the bottom surface 61, and is bent to cover the rear part of the wound body 50. A first slit 73 and a second slit 74 are formed at the rear edge of the rear surface 63 in the front-rear direction L.

[0044] The first slit 73 is provided at a position corresponding to the negative electrode current collecting portion 30 and the positive electrode current collecting portion 40, and includes a positive electrode side first slit 73A formed on the other side in the width direction W of the rear surface 63 and a negative electrode side first slit 73B formed on one side in the width direction W of the rear surface 63. The second slit 74 is provided at a position corresponding to the injection port 21A (see FIG. 1), and includes a positive electrode side second slit 74A formed on the other side in the width direction W of the rear surface 63 and a negative electrode side second slit 74B formed on one side in the width direction W of the rear surface 63.

[0045] The positive electrode side first slit 73A, the negative electrode side first slit 73B, the positive electrode side second slit 74A, and the negative electrode side second slit 74B extend in the front-rear direction L and are formed to have the same length. In other words, the positive electrode side first slit 73A, the negative electrode side first slit 73B, the positive electrode side second slit 74A, and the negative electrode side second slit 74B extend in the vertical direction and are formed to have the same length.

[0046] The rear surface 63 is formed with a first rear surface edge 63A, a second rear surface edge 63B, a third rear surface edge 63C, a fourth rear surface edge 63D, and a fifth rear surface edge 63E by the first slit 73 and the second slit 74.

[0047] The first rear surface edge 63A is formed between the rear side surface 65 and the positive electrode side first slit 73A. The second rear surface edge 63B is formed between the positive electrode side first slit 73A and the positive electrode side second slit 74A. The third rear surface edge 63C is formed between the positive electrode side second slit 74A and the negative electrode side second slit 74B. The fourth rear surface edge 63D is formed between the negative electrode side second slit 74B and the negative electrode side first slit 73B. The fifth rear surface edge 63E is formed between the negative electrode side first slit 73B and the rear side surface 65.

[0048] The length of the first rear surface edge 63A in the width direction W is made substantially the same as the length of the first insulating member 44 (see FIG. 3) in the width direction W. The length of the fifth rear surface edge 63E in the width direction W is made substantially the same as the length of the first insulating member 34 (see FIG. 3) in the width direction W. The length of the third rear surface edge 63C in the width direction W is made substantially the same as the length of the injection port 21A (see FIG. 1) in the width direction W.

[0049] The second rear surface edge 63B and the fourth rear surface edge 63D are bent to cover the upper part of the rear side of the wound body 50.

[0050] 〈Front side surface 64〉 The front side surface 64 is formed as a rectangle continuous with the front surface 62, and is bent to cover the side part of the front side of the wound body 50.

[0051] 〈Rear side surface 65〉 The rear side surface 65 is formed as a rectangle continuous with the rear surface 63, and is bent to cover the side portion on the rear side of the wound body 50. That is, the insulating film 60 covers the entire circumference of the wound body 50. In other words, the insulating film 60 covers the front portion, the rear portion, the bottom portion, the side portions, and the upper portion of the wound body 50.

[0052] As shown in FIG. 3, the tip of the bent front side surface 64 and the tip of the bent rear side surface 65 overlap to form an overlapping portion 66. The tip of the bent second front edge 62B and the tip of the bent second rear edge 63B overlap to form an overlapping portion 66B. The tip of the bent fourth front edge 62D and the tip of the bent fourth rear edge 63D overlap to form an overlapping portion 66D.

[0053] That is, the insulating film 60 is formed in a bag shape by joining the ends of the insulating film 60 together.

[0054] As shown in FIG. 3, a first opening 81 and a second opening 82 are formed in the insulating film 60 formed in a bag shape.

[0055] 〈First Opening 81〉 The first opening 81 includes a positive electrode opening 81A opened for the positive electrode current collector 40 and a negative electrode opening 81B opened for the negative electrode current collector 30.

[0056] The positive electrode opening 81A is formed by the unbent first front edge 62A, the unbent first rear edge 63A, the front side surface 64, and the rear side surface 65. In other words, the positive electrode opening 81A is formed by forming a positive electrode side first slit 71A and a positive electrode side first slit 73A in the insulating film 60.

[0057] The first front edge 62A, the first rear edge 63A, the front side surface 64, and the rear side surface 65 are joined to the side surface of the first insulating member 44, for example, by thermal welding. In other words, the edge of the insulating film 60 that forms the positive electrode opening 81A is joined to the first insulating member 44. As a result, the positive electrode opening 81A is blocked by the first insulating member 44. A part of the terminal portion 40A penetrates and is disposed in the positive electrode opening 81A.

[0058] The negative electrode opening 81B is formed by the non-folded fifth front edge 62E, the non-folded fifth rear edge 63E, the front side surface 64, and the rear side surface 65. In other words, by forming the negative electrode side first slit 71B and the negative electrode side first slit 73B in the insulating film 60, the positive electrode opening 81A is formed.

[0059] The fifth front edge 62E, the fifth rear edge 63E, the front side surface 64, and the rear side surface 65 are joined to the side surface of the first insulating member 34, for example, by thermal welding. In other words, the edge of the insulating film 60 that forms the negative electrode opening 81B is joined to the first insulating member 34. As a result, the negative electrode opening 81B is blocked by the first insulating member 34. A part of the terminal portion 30A penetrates and is disposed in the negative electrode opening 81B.

[0060] 〈Second Opening 82〉 The second opening 82 is formed by the non-folded third front edge 62C and the non-folded third rear edge 63C. In other words, by forming the positive electrode side second slit 72A, the negative electrode side second slit 72B, the positive electrode side second slit 74A, and the negative electrode side second slit 74B in the insulating film 60, the second opening 82 is formed.

[0061] The second opening 82 is provided at a position corresponding to the injection port 21A, and as shown in FIG. 4, it is formed to have a size into which the nozzle 90 that is inserted into the injection port 21A and supplies the electrolytic solution U can be inserted.

[0062] (Case 12) As shown in FIG. 1, the case 12 is made of, for example, aluminum, and is formed in a rectangular box shape that is long in the left-right direction with an open upper surface and an opening 12A formed therein.

[0063] As shown in FIG. 4, inside the case 12, a wound body 50 to which a negative electrode current collector terminal 32 and a positive electrode current collector terminal 42 are joined is accommodated in a state covered with an insulating film 60, and a lid body 21 is attached so as to close the opening 12A of the case 12 by, for example, laser welding. And the electrolytic solution U is injected into the case 12 from an injection port 21A provided in the lid body 21.

[0064] In the battery cell 10 configured as described above, the output of the wound body 50 is taken out from the negative electrode external terminal 38 and the positive electrode external terminal 48, and it is used as a power source for an electric vehicle, a hybrid vehicle, or the like.

[0065] [Operation] The battery cell 10 of the embodiment includes a wound body 50, a case 12 having an opening 12A and accommodating the wound body 50 together with the electrolytic solution U, a lid body 21 closing the opening 12A and having an injection port 21A for the electrolytic solution U formed therein, first insulating members 34 and 44 disposed between the lid body 21 and terminal portions 30A and 40A connected to the wound body 50, and an insulating film 60 covering all directions of the wound body 50 and a part of the terminal portions 30A and 40A and having a first opening 81 through which the terminal portions 30A and 40A are disposed, and an edge portion forming the first opening 81 is joined to the first insulating members 34 and 44 (see FIG. 3).

[0066] By providing the insulating film 60 that covers all directions of the wound body 50 and a part of the terminal portions 30A and 40A and has a first opening 81 through which the terminal portions 30A and 40A are disposed, and an edge portion forming the first opening 81 is joined to the first insulating members 34 and 44, substantially the entire surface of the wound body 50 is covered, and the first opening 81 is blocked by the first insulating members 34 and 44. Therefore, leakage of the electrolytic solution U to the outside of the insulating film 60 can be suppressed.

[0067] In the battery cell 10 of the embodiment, the insulating film 60 is provided with a second opening 82 at a position corresponding to the injection port 21A (see FIG. 3).

[0068] Since the insulating film 60 is provided with the second opening 82 at a position corresponding to the injection port 21A, an opening through which the electrolytic solution U is injected into the insulating film 60 is formed. Therefore, while suppressing the leakage of the electrolytic solution U to the outside of the insulating film 60, the electrolytic solution U can be appropriately injected into the insulating film 60 formed in a bag shape.

[0069] In the battery cell 10 of the embodiment, the first opening 81 and the second opening 82 are formed by first slits 71, 73 and second slits 72, 74 extending in the vertical direction at the upper end of the insulating film 60 (see FIG. 2).

[0070] Since the first opening 81 and the second opening 82 are formed by the first slits 71, 73 and the second slits 72, 74 extending in the vertical direction at the upper end of the insulating film 60, when the upper end of the insulating film 60 is bent, the upper surface of the wound body 50 is covered with the insulating film 60. In addition, the first opening 81 and the second opening 82 are formed by the non-bent portion of the upper end of the insulating film 60. Therefore, a bag-shaped insulating film 60 having the first opening 81 and the second opening 82 can be formed with a simple configuration.

[0071] In the battery cell 10 of the embodiment, the slits include first slits 71, 73 that form the first opening 81 and second slits 72, 74 that form the second opening 82, and the first slits 71, 73 and the second slits 72, 74 are formed to have the same length (see FIG. 2).

[0072] The first slits 71 and 73 are formed to have the same length as the second slits 72 and 74. Thus, when the upper ends of the insulating film 60 between the first slits 71 and 73 and the second slits 72 and 74 are bent, the upper surface of the wound body 50 is covered with the insulating film 60. Also, the first opening 81 and the second opening 82 are formed by the portions of the insulating film 60 where the upper ends are not bent. Therefore, with a simple configuration, the first opening 81 and the second opening 82 can be formed and the upper surface of the wound body 50 can be covered.

[0073] In the battery cell 10 of the embodiment, the insulating film 60 is formed in a bag shape by joining the ends of the insulating film 60 together (see FIG. 2).

[0074] Since the insulating film 60 is formed in a bag shape by joining the ends of the insulating film 60 together, the insulating film 60 is formed in a bag shape with a simple configuration. Therefore, with a simple configuration, leakage of the electrolytic solution U to the outside of the insulating film 60 can be suppressed.

[0075] As described above, the secondary battery of the present invention has been described based on the embodiment. However, the specific configuration is not limited to this embodiment, and design changes and the like are allowed as long as the gist of the invention according to each claim of the claims is not deviated from.

[0076] In the embodiment, an example is shown in which the first slit 71 and the second slit 72 are formed on the front surface 62, and the first slit 73 and the second slit 74 are formed on the rear surface 63 to cover the upper part of the wound body 50. However, a slit may be formed on either the front surface or the rear surface to cover the upper part of the wound body.

[0077] In the embodiment, an example is shown in which the insulating film 60 is formed in a bag shape by joining the ends together. However, the ends of the insulating film may not be joined together.

[0078] In the embodiment, an example is shown in which the insulating film 60 is bent so as to sandwich the wound body 50 between the front surface 62 and the rear surface 63 and is formed in a bag shape. However, the method of bending the insulating film is not limited to this mode. Also, two or more insulating films may be joined to form a bag shape.

[0079] In the embodiment, an example is shown in which the electrode body is of a wound type wound in a state where a negative electrode sheet, a positive electrode sheet, and a separator are laminated. However, the electrode body may be of a laminated type in which a negative electrode sheet, a positive electrode sheet, and a separator are laminated.

[0080] In the embodiment, an example is shown in which the secondary battery is a lithium-ion secondary battery. However, the secondary battery can be other batteries.

Explanation of Reference Numerals

[0081] 10 Battery cell (an example of a secondary battery) 12 Case 12A Opening 21 Lid 21A Inlet 30 Wound body (an example of an electrode body) 30A, 40A Terminal portion 34, 44 First insulating member 60 Insulating film 71 First opening 71, 73 First slit (an example of a slit) 72, 74 Second slit (an example of a slit) U Electrolyte

Claims

1. An electrode body, a case having an opening and accommodating the electrode body together with an electrolytic solution, a lid body that closes the opening and forms an injection port for the electrolytic solution, an insulating member disposed between the lid body and a terminal portion connected to the electrode body, an insulating film that covers all directions of the electrode body and a part of the terminal portion, and has a first opening through which the terminal portion is disposed, and an edge portion forming the first opening is joined to the insulating member, A secondary battery comprising the above.

2. The insulating film has a second opening at a position corresponding to the injection port. The secondary battery according to Claim 1.

3. The first opening and the second opening are formed by slits extending in the vertical direction at the upper end of the insulating film. The secondary battery according to Claim 2.

4. The slit includes a first slit forming the first opening and a second slit forming the second opening, The first slit and the second slit are formed to have the same length. The secondary battery according to Claim 3.

5. The insulating film is formed in a bag shape by joining the ends of the insulating film to each other. The secondary battery according to Claim 1.

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