Secondary battery

Abstract

The utility model provides a secondary battery capable of inhibiting the influence of external force on a current collection contact pin. The secondary battery is provided with: an electrode body for accommodating a cylindrical member of the electrode body; a pair of sealing bodies for closing a pair of openings provided on both sides of the cylindrical member in the axial direction of the cylinder; a first external terminal provided on one sealing body of the pair of sealing bodies; and a second external terminal provided on the other sealing body of the pair of sealing bodies. And a spacer disposed inside the cylindrical member. The electrode body has a first end portion on one side and a second end portion on the other side in a parallel direction parallel to the cylinder axis direction, the first end portion being provided with one or more first current collector tabs electrically connected to the first external terminal, and the second end portion being provided with one or more second current collector tabs electrically connected to the second external terminal. The spacer includes a first member provided between one sealing body and the first end, and a second member provided between the other sealing body and the second end.

Description

Technical Field

[0001] The utility model relates to a secondary battery, and in particular to a secondary battery mounted on a vehicle. Background Art

[0002] As an existing secondary battery, Japanese Patent Publication No. 2021-044082 discloses that an electrode body having a current collector tab disposed at the upper end of the electrode body is housed in a shell, and an impact absorbing component is arranged between the electrode body and the shell. The shell is composed of a main body opening upward and a sealing body that closes the opening of the main body. The impact absorbing component is formed into a bottomed cylindrical bag opening upward, and is arranged to surround the electrode body around an axis parallel to the up-down direction.

[0003] In recent years, secondary batteries have been required to be low in height and high in capacity. In order to achieve such requirements, it is considered to reduce the height of the electrode body to make it horizontally long. In such a case, it is considered to accommodate the electrode body in a cylindrical member with openings on both sides in the horizontal direction, and to block the openings of the cylindrical member on both sides in the horizontal direction with a pair of sealing bodies provided with external terminals.

[0004] When a secondary battery is mounted on a vehicle, the electrode body may move in the lateral direction (the axial direction of the cylindrical member) due to the vibration of the vehicle. If no measures are taken in such a situation, the collector tab on the opposite side of the moving direction of the electrode body may be pulled. This may cause the collector tab to be damaged or the electrical connection between the collector tab and the external terminal to be disconnected. Utility Model Content

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a secondary battery capable of suppressing the influence of external force on a current collecting tab.

[0006] The secondary battery of the utility model comprises: an electrode body; a cylindrical component for accommodating the electrode body; a pair of sealing bodies, which close a pair of openings arranged on both sides of the cylindrical component in the cylindrical axis direction; a first external terminal arranged on the sealing body of one of the pair of sealing bodies; a second external terminal arranged on the sealing body of the other of the pair of sealing bodies; and a spacer arranged inside the cylindrical component, the electrode body having a first end portion located on one side of a parallel direction parallel to the cylindrical axis direction and a second end portion located on the other side of the parallel direction, the first end portion being provided with one or more first current collecting tabs electrically connected to the first external terminal, the second end portion being provided with one or more second current collecting tabs electrically connected to the second external terminal, the spacer comprising a first component arranged between the sealing body of the one side and the first end portion, and a second component arranged between the sealing body of the other side and the second end portion.

[0007] According to the above structure, a spacer is arranged between the two ends of the electrode body and the pair of sealing bodies. Thus, the spacer can be used to act as a resistance in the opposite direction to the external force moving in the direction parallel to the cylinder axis direction. Thus, the movement of the electrode body can be suppressed, and one of the first collector tab and the second collector tab can be suppressed from being stretched as the electrode body moves. As a result, the influence of external forces caused by vibrations, etc. on the collector tabs can be suppressed.

[0008] In the secondary battery based on the above utility model, the spacer may be elastic. According to the above structure, in addition to the above resistance, elastic force can be applied to the electrode body. Thus, the movement of the electrode body can be further suppressed, and the influence of external forces caused by vibration on the current collector tab can be further suppressed.

[0009] According to the secondary battery of the utility model described above, it can also further include: a first conductive component, which is connected to the first external terminal and includes a first relative portion opposite to the first end in the parallel direction; and a second conductive component, which is connected to the second external terminal and includes a second relative portion opposite to the second end in the parallel direction, the one or more first current collecting tabs can be connected to the first relative portion at a front end side in a state where they are folded back in a cross direction intersecting the parallel direction in a manner including portions opposite to the parallel direction separated by a first gap, and the one or more second current collecting tabs can be connected to the second relative portion at a front end side in a state where they are folded back in the cross direction in a manner including portions opposite to the parallel direction separated by a second gap, the first component can be arranged in the first gap, and the second component can be arranged in the second gap.

[0010] According to the above structure, when a tensile force acts on one side of the first current collecting tab and the second current collecting tab in the moving direction of the electrode body as the electrode body moves in a direction parallel to the cylinder axis direction, the spacer can be used to make the resistance to the tensile force act on the connection between the first current collecting tab and the first opposing part, or the connection between the second current collecting tab and the second opposing part. Thus, the influence of external force caused by vibration or the like on the current collecting tab can be more preferably suppressed.

[0011] According to the present invention, a secondary battery capable of suppressing the influence of external force on the current collecting tab can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a perspective view of a secondary battery according to one embodiment.

[0013] Figure 2 This is an exploded perspective view of a secondary battery according to one embodiment.

[0014] Figure 3 For along Figure 1 A cross-sectional view of a secondary battery taken along line III-III is shown.

[0015] Figure 4 For along Figure 1 A cross-sectional view of the secondary battery taken along line IV-IV is shown.

[0016] Figure 5 For along Figure 3 The cross-sectional view of the secondary battery taken along line VV is shown. DETAILED DESCRIPTION

[0017] The following is a detailed description of the embodiments of the present invention with reference to the accompanying drawings. In the embodiments shown below, the same or corresponding parts in the drawings are denoted by the same reference numerals, and their description is omitted.

[0018] Figure 1 This is a perspective view of a secondary battery according to one embodiment. Figure 2 This is an exploded perspective view of a secondary battery according to one embodiment. Figure 3 For along Figure 1 The cross-sectional view of the secondary battery along the line III-III is shown. Figures 1 to 3 The secondary battery 10 according to the embodiment will be described.

[0019] like Figures 1 to 3 As shown, the secondary battery 10 according to the first embodiment includes an electrode body 100 , a frame body 200 , a negative electrode member 520 as one external terminal (first external terminal), a positive electrode member 620 as the other external terminal (second external terminal), and a separator 40 .

[0020] The electrode body 100 has a first end 101 located on one side of the width direction W of the frame 200 and a second end 102 located on the other side of the width direction W. The width direction W is a direction parallel to the cylindrical axis direction of the cylindrical member 210 described later. A plurality of negative electrode tabs 110N are provided at the first end 101 as one or more first current collecting tabs. A plurality of positive electrode tabs 110P are provided at the second end 102 as one or more second current collecting tabs. In addition, the negative electrode tab 110N and the positive electrode tab 110P may also be single. The detailed structure of the electrode body 100 will be described later using Figure 4 Give a narrative.

[0021] The frame body 200 has a rectangular parallelepiped shape in which the thickness in the thickness direction T is smaller than the width in the width direction W and the height in the height direction H. The thickness direction T is aligned with the positive electrode 110 (see Figure 4 ) and the negative electrode 120 (refer to Figure 4) are arranged in parallel. The width direction W is perpendicular to the thickness direction T. The height direction H is perpendicular to the thickness direction T and the height direction H. The width of the frame body 200 in the width direction W is greater than the height of the frame body 200 in the height direction H.

[0022] The frame 200 accommodates the electrode body 100 and an electrolyte solution (not shown) therein. The frame 200 includes a cylindrical member 210 for accommodating the electrode body 100 and a first sealing body 510 and a second sealing body 610 as a pair of sealing bodies.

[0023] The cylindrical member 210 has a pair of openings disposed on both sides in the cylindrical axis direction. The pair of openings includes a first opening 215 and a second opening 216. The first opening 215 is disposed on one side in the width direction W, and the second opening 216 is disposed on the other side in the width direction W. The cylindrical member 210 is made of a metal such as aluminum.

[0024] A spacer 40 is disposed inside the tubular member 210. The spacer 40 is composed of, for example, an insulating member. The spacer 40 may also have elasticity. The spacer 40 includes a first member 41 and a second member 42 described later. The spacer 40 (the first member 41 and the second member 42, respectively) may be composed of a polyethylene or polypropylene foam, styrene rubber, ethylene-propylene rubber, etc. The first member 41 and the second member 42 may also have, for example, a leaf spring shape.

[0025] The first sealing body 510 seals the first opening 215. The first sealing body 510 has a flat plate shape. The first sealing body 510 is made of a metal such as aluminum. The first sealing body 510 is fixed to the first opening 215 by laser welding or the like, for example.

[0026] The second sealing body 610 seals the second opening 216. The second sealing body 610 has a flat plate shape. The second sealing body 610 is made of a metal such as aluminum. The second sealing body 610 is fixed to the second opening 216 by laser welding or the like, for example.

[0027] The first sealing body 510 and the second sealing body 610 are provided with a pressure release valve 222 and a liquid injection port 224, respectively. The pressure release valve 222 is configured to rupture when the internal pressure of the frame body 200 reaches a predetermined pressure or more. When the pressure release valve 222 ruptures, the gas in the frame body 200 is discharged to the outside of the frame body 200, so that the internal pressure in the frame body 200 is reduced.

[0028] The liquid injection port 224 is a through hole for injecting electrolyte into the frame 200 during the manufacturing process of the secondary battery 10. The liquid injection port 224 is sealed by a sealing component 225. The sealing component 225 is a component that seals the liquid injection port 224 after the electrolyte is injected into the frame 200. As the sealing component 225, for example, it can be a vent film that does not allow liquid to pass through but allows gas to pass through. In this case, when the gas generated during charging is discharged to the outside of the frame 200, the gas can be discharged through the vent film. As a result, there is no need to set up an exhaust port separately. In addition, it is possible to suppress the electrolyte from leaking out of the frame 200 due to the vent film. In addition, the sealing component 225 is not limited to the vent film, and a resin component, a metal component, etc. can be appropriately used.

[0029] A negative electrode component 520 is provided on the first sealing body 510 , and a positive electrode component 620 is provided on the second sealing body 610 .

[0030] The negative electrode member 520 is provided on the outer surface of the first sealing body 510 . The negative electrode member 520 functions as a negative electrode terminal. The negative electrode member 520 includes a negative electrode terminal plate 521 and an insulating plate 522 .

[0031] The negative terminal plate 521 is formed in a substantially rectangular parallelepiped shape. The negative terminal plate 521 is held by an insulating plate 522. The insulating plate 522 is fixed to the outer surface of the first sealing body 510. The insulating plate 522 insulates the first sealing body 510 from the negative terminal plate 521. A through hole for inserting a first connecting portion 532 described later is provided in each of the negative terminal plate 521 and the insulating plate 522.

[0032] The positive electrode member 620 is provided on the outer surface of the second sealing body 610 . The positive electrode member 620 functions as a positive electrode terminal. The positive electrode member 620 includes a positive electrode terminal plate 621 and a terminal block 622 .

[0033] The positive electrode terminal plate 621 is formed in a rectangular parallelepiped shape and is made of metal such as aluminum.

[0034] The terminal block 622 is formed in a rectangular parallelepiped shape. The terminal block 622 is made of a metal (iron, etc.) different from the metal constituting the positive terminal plate 621. The terminal block 622 is fixed to the outer surface of the second sealing body 610 by welding or the like. The positive terminal plate 621 is fixed to the terminal block 622 by welding or the like. The tubular member 210 and the second sealing body 610 are electrically connected to the positive terminal plate 621 via the terminal block 622, and are charged to the same polarity as the positive terminal plate 621. A through hole for inserting the second connecting portion 632 described later is formed in the positive terminal plate 621 and the terminal block 622, respectively.

[0035] In addition, an insulating plate may be disposed between the positive electrode member 620 and the second sealing body 610 to electrically insulate the positive electrode member 620 from the second sealing body 610. In this case, an insulating plate may be disposed instead of the terminal block 622, or an insulating plate may be disposed between the terminal block 622 and the second sealing body 610.

[0036] The secondary battery 10 further includes a first conductive member 530 and an insulator 560 on the negative electrode member 520 side.

[0037] The first conductive component 530 connects a plurality of negative electrode tabs 110N to the negative terminal plate 521. The plurality of negative electrode tabs 110N are connected to the first conductive component 530 in a bundled state by ultrasonic welding or the like. The first conductive component 530, for example, has a first relative portion 531 and a first connecting portion 532. The first relative portion 531 has a plate-like shape. The first relative portion 531 is substantially parallel to the inner surface of the first sealing body 510. The first relative portion 531 is opposite to the first end portion 101 of the electrode body 100 in the width direction W. The first connecting portion 532 extends in a direction parallel to the first direction. The first connecting portion 532 has, for example, a cylindrical shape. The front end portion of the first connecting portion 532 passes through the first sealing body 510, the insulating plate 522 and the negative terminal plate 521, and is riveted to the negative terminal plate 521.

[0038] The insulator 560 is disposed between the first opposing portion 531 and the first sealing member 510 to insulate the first opposing portion 531 and the first sealing member 510. The insulator 560 includes a portion covering the periphery of the base end side of the first connecting portion 532 and a portion located between the first opposing portion 531 and the inner surface of the first sealing member 510.

[0039] The negative electrode member 520 , the first sealing member 510 , the first conductive member 530 , and the insulator 560 are assembled to form the first cap assembly 50 .

[0040] The first cap assembly 50 is fixed to the tubular member 210 by attaching the first sealing body 510 to the first opening 215 in a state where the plurality of negative electrode tabs 110N and the first conductive member 530 are fixed by welding or the like.

[0041] The secondary battery 10 further includes a second conductive member 630 and an insulator 660 on the positive electrode member 620 side.

[0042] The second conductive component 630 connects a plurality of positive electrode tabs 110P to the positive terminal plate 621. The plurality of positive electrode tabs 110P are connected to the second conductive component 630 in a bundled state by ultrasonic welding or the like. The second conductive component 630 includes a second relative portion 631 and a second connecting portion 632. The second relative portion 631 has a plate-like shape. The second relative portion 631 is substantially parallel to the inner surface of the second sealing body 610. The second relative portion 631 is opposite to the second end portion 102 of the electrode body 100 in the width direction W. The second connecting portion 632 extends in a direction parallel to the first direction. The second connecting portion 632 has, for example, a cylindrical shape. The front end portion of the second connecting portion 632 passes through the second sealing body 610, the terminal block 622 and the positive terminal plate 621, and is riveted to the positive terminal plate 621.

[0043] The insulator 660 is disposed between the second opposing portion 631 and the second sealing member 610 to insulate the second opposing portion 631 and the second sealing member 610. The insulator 660 includes a portion covering the periphery of the base end side of the second connecting portion 632 and a portion located between the second opposing portion 631 and the inner surface of the second sealing member 610.

[0044] The positive electrode member 620 , the second sealing member 610 , the second conductive member 630 , and the insulator 660 are assembled to form the second cap assembly 60 .

[0045] The second cap assembly 60 is fixed to the tubular member 210 by attaching the second sealing body 610 to the second opening 216 in a state where the plurality of positive electrode tabs 110P and the second conductive member 630 are fixed by welding or the like.

[0046] Figure 4 For along Figure 1 The cross-sectional view of the secondary battery taken along line IV-IV is shown. Figure 4 The detailed structure of the electrode body of the secondary battery is described. Figure 4 In the figure, for convenience, the frame 200 of the secondary battery 10 is omitted, and only the electrode body 100 is shown. Figure 4 The electrode body 100 will be described in detail.

[0047] like Figure 4 As shown, the electrode body 100 includes a plurality of positive electrodes 110 , a plurality of negative electrodes 120 , and a separator 130 . The plurality of positive electrodes 110 and the plurality of negative electrodes 120 are arranged alternately in the thickness direction T while being insulated by the separator 130 .

[0048] Each negative electrode 120 is formed in a rectangular shape with a length in the width direction W and a short side in the height direction H. Each negative electrode 120 includes a negative electrode collector foil 122 and negative electrode active material layers 124 provided on both sides of the negative electrode collector foil 122. The negative electrode collector foil 122 includes a negative electrode tab 110N on which the negative electrode active material layer 124 is not provided. The negative electrode tab 110N protrudes toward one side in the width direction W.

[0049] Each positive electrode 110 is formed in a rectangular shape with a width direction W as a length and a height direction H as a short side. Each positive electrode 110 includes a positive electrode collector foil 112 and a positive electrode active material layer 114 provided on both sides of the positive electrode collector foil 112 in the thickness direction T. The positive electrode collector foil 112 includes a positive electrode tab 110P on which the positive electrode active material layer 114 is not provided. The positive electrode tab 110P protrudes toward the other side in the width direction W.

[0050] The separator 130 insulates the positive electrode 110 from the negative electrode 120. The separator 130 is made of an insulating material and has tiny gaps that allow ions to pass through. The separator 130 is formed in a meandering shape.

[0051] The separator 130 has a rectangular shape before being formed into a meandering shape. The separator 130 is disposed in a meandering shape between the positive electrode 110 and the negative electrode 120. The separator 130 has a plurality of intermediate portions 132a, a plurality of first folded portions 132b, a plurality of second folded portions 132c, and an outermost coating portion 132d.

[0052] Each intermediate portion 132a is interposed between the positive electrode 110 and the negative electrode 120 adjacent to each other in the thickness direction T. That is, each intermediate portion 132a has a function of insulating the positive electrode 110 and the negative electrode 120. Each intermediate portion 132a is composed of a rectangular region.

[0053] Each first folded portion 132b connects one end portion in the height direction H of the intermediate portions 132a adjacent to each other in the thickness direction T so that the positive electrode 110 is located therebetween. The first folded portion 132b is disposed on one side in the height direction H of the positive electrode 110 (upper side).

[0054] Each second folded portion 132c connects the other ends of the intermediate portions 132a adjacent to each other in the thickness direction T in the other direction of the height direction H so that the negative electrode 120 is located therebetween. The second folded portion 132c is disposed on the other side (lower side) in the height direction H of the negative electrode 120 .

[0055] The outermost covering portion 132d covers the first folding portions 132b and the second folding portions 132c in a concentrated manner. In more detail, the outermost covering portion 132d covers all positive electrodes 110, all negative electrodes 120, all intermediate portions 132a, all first folding portions 132b, and all second folding portions 132c as a whole in a manner surrounding a central axis parallel to the width direction W. The end 132e of the outermost covering portion 132d is set within a range that does not overlap with the positive electrode active material layer 114 and the negative electrode active material layer 124 in the thickness direction T. In the present embodiment, the end 132e of the outermost covering portion 132d is disposed below each positive electrode 110 and each negative electrode 120. In addition, an insulating film (not shown) may be coated on the peripheral surface and bottom surface of multiple positive electrodes 110, multiple negative electrodes 120, and the separator 130.

[0056] Figure 5 For along Figure 3 The cross-sectional view of the secondary battery taken along the VV line is shown. Figure 5 Detailed description will be given of the connection method of the first member 41 and the second member 42 constituting the separator 40 and the plurality of negative electrode tabs 110N and the plurality of positive electrode tabs 110P.

[0057] The front end side of the plurality of negative electrode tabs 110N is connected to the first opposing portion 531 in a state where the plurality of negative electrode tabs 110N are folded back in a direction intersecting the width direction W so as to include the portions facing each other in the width direction W with the first gap G1 therebetween. The front end side of the negative electrode tab 110N refers to the side opposite to the side where the first end 101 is located. The plurality of negative electrode tabs 110N are folded back in a substantially U-shape.

[0058] The plurality of positive electrode tabs 110P are folded in a direction intersecting the width direction W so as to include the portions facing each other in the width direction W with the second gap G2 therebetween, and the front end side of the plurality of positive electrode tabs 110P is connected to the second facing portion 631. The front end side of the positive electrode tab 110P refers to the side opposite to the side where the second end 102 is located. The plurality of positive electrode tabs 110P are folded in a substantially U-shape.

[0059] The first member 41 is disposed between the first sealing body 510 and the first end 101 of the electrode body 100. Specifically, it is disposed in the first gap G1. The second member 42 is disposed between the second sealing body 610 and the second end 102 of the electrode body 100. Specifically, it is disposed in the second gap G2.

[0060] As described above, by providing the first member 41 and the second member 42 as the spacer 40, when an external force that moves the electrode body 100 in a direction parallel to the cylinder axis direction (width direction W) is applied to the electrode body 100 due to vibration or the like, resistance can be applied in a direction opposite to the moving direction of the electrode body 100 by the first member 41 or the second member 42. Thus, the movement of the electrode body 100 can be suppressed, and one of the negative electrode tab 110N and the positive electrode tab 110P can be suppressed from being stretched along with the movement of the electrode body 100. As a result, the influence of the external force caused by vibration or the like on the electrode body 100 can be suppressed.

[0061] Furthermore, since the first member 41 and the second member 42 have elasticity, in addition to the above-mentioned resistance, elastic force can be applied to the electrode body 100. This can further suppress the movement of the electrode body 100 and further suppress the influence of external force caused by vibration on the current collecting tab.

[0062] In addition, by disposing the first member 41 and the second member 42 in the first gap G1 and the second gap G2, respectively, when a tensile force acts on one side of the negative electrode tab 110N and the positive electrode tab 110P in the moving direction of the electrode body 100 due to vibration or the like, resistance to the tensile force can be applied to the connection between the negative electrode tab 110N and the first opposing portion 531, or the connection between the positive electrode tab 110P and the second opposing portion 631, by the first member 41 and the second member 42. Thus, the influence of external force caused by vibration or the like on the current collecting tabs can be more preferably suppressed.

[0063] The embodiments disclosed herein are illustrative in all aspects and are not restrictive. The scope of the present invention is indicated by the claims, and includes all modifications within the meaning and scope equivalent to the claims.

Claims

1. A secondary battery, characterized in that: have: Electrode body; A cylindrical component for accommodating the electrode body; A pair of sealing bodies, which seal a pair of openings provided on both sides of the cylindrical member in the cylindrical axis direction; A first external terminal is provided on one of the sealing bodies of the pair of sealing bodies; A second external terminal is provided on the other sealing body of the pair of sealing bodies; and a spacer disposed inside the cylindrical member, The electrode body has a first end portion located on one side of a parallel direction parallel to the cylinder axis direction and a second end portion located on the other side of the parallel direction. The first end portion is provided with one or more first current collecting tabs electrically connected to the first external terminal. The second end portion is provided with one or more second current collecting tabs electrically connected to the second external terminal. The spacer includes a first member provided between the one sealing body and the first end portion, and a second member provided between the other sealing body and the second end portion.

2. The secondary battery according to claim 1, characterized in that: The spacer has elasticity.

3. The secondary battery according to claim 1 or 2, characterized in that: The secondary battery also has: a first conductive member connected to the first external terminal and including a first opposing portion opposing the first end portion in the parallel direction; and a second conductive member connected to the second external terminal and including a second opposing portion opposing the second end portion in the parallel direction, The one or more first current collecting tabs are folded back in a direction intersecting the parallel direction so as to include the portions facing each other in the parallel direction with a first gap therebetween, and the front end portions thereof are connected to the first facing portion. The one or more second current collecting tabs are folded back in the intersecting direction so as to include the portions facing each other in the parallel direction with a second gap therebetween, and the front end portions thereof are connected to the second facing portions. The first component is arranged in the first gap, The second component is disposed in the second gap.

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