Secondary batteries

Abstract

To provide a secondary battery in which the influence of an external force on a current collector tab can be suppressed.SOLUTION: A secondary battery 10 includes an electrode assembly 100, a tubular member 210, a pair of sealing bodies 510 and 610, a first external terminal 520, a second external terminal 620, and a spacer 40 disposed inside the tubular member 210. The electrode assembly 100 has a first end portion 101 located on one side in a parallel direction parallel to a cylindrical axis direction and a second end portion 102 located on the other side in the parallel direction. The first end portion 101 is provided with one or more first current collector tabs electrically connected to the first external terminal 520, and the second end portion 102 is provided with one or more second current collector tabs electrically connected to the second external terminal 620. The spacer 40 includes a first member 41 provided between the one sealing body 510 and the first end portion 101, and a second member 42 provided between the other sealing body 610 and the second end portion 102.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to secondary batteries, and more particularly to secondary batteries mounted in vehicles.

Background Art

[0002] As a conventional secondary battery, Japanese Patent Application Laid-Open No. 2021-044082 (Patent Document 1) discloses a configuration in which an electrode body provided with a current collecting tab at its upper end is housed in a case, and a shock absorbing member is disposed between the electrode body and the case. The case is composed of a main body portion that opens upward and a sealing body that closes the opening of the main body portion. The shock absorbing member is formed in a bottomed cylindrical bag shape that opens upward, and is provided so as to surround the electrode body around an axis parallel to the vertical direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, in secondary batteries, there has been a demand for lower profile and higher capacity. To meet such requirements, it is conceivable to reduce the height of the electrode body and make it horizontally long. In such a case, a configuration is conceivable in which the electrode body is housed in a cylindrical member having openings on both lateral sides in the horizontal direction, and the openings of the cylindrical members provided on both lateral sides in the horizontal direction are closed by a pair of sealing bodies provided with external terminals.

[0005] When a secondary battery is mounted in a vehicle or the like, the electrode body may move in the horizontal direction (the axial direction of the cylindrical member) due to vibrations of the vehicle or the like. If there is no measure in such a case, the current collecting tab located on the opposite side to the moving direction of the electrode body will be pulled. As a result, the current collecting tab may be damaged or the electrical connection between the current collecting tab and the external terminal may be disconnected.

[0006] This disclosure has been made in view of the above-mentioned problems, and the purpose of this disclosure is to provide a secondary battery capable of suppressing the influence of external forces on the current collector tab. [Means for solving the problem]

[0007] A secondary battery according to this disclosure comprises an electrode body, a cylindrical member housing the electrode body, a pair of sealing bodies that close a pair of openings provided on both sides of the cylindrical member in the direction of the cylindrical axis, a first external terminal provided on one of the pair of sealing bodies, a second external terminal provided on the other of the pair of sealing bodies, and a spacer disposed inside the cylindrical member. The electrode body has a first end located on one side in a parallel direction parallel to the direction of the cylindrical axis and a second end located on the other side in the parallel direction. The first end is provided with one or more first current collector tabs electrically connected to the first external terminal. The second end is 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 of the sealing bodies and the first end, and a second member provided between the other sealing body and the second end.

[0008] According to the above configuration, spacers are placed between both ends of the electrode body and a pair of sealing bodies. This allows the spacers to act as a counterforce in the opposite direction to an external force that moves the electrode body in a direction parallel to the cylindrical axis. This suppresses the movement of the electrode body and prevents one of the first and second current-collecting tabs from being pulled as the electrode body moves. As a result, the influence of external forces on the current-collecting tabs due to vibration and the like can be suppressed.

[0009] In the secondary battery based on the above disclosure, the spacer may be elastic. According to the above configuration, elastic force can be applied to the electrode body in addition to drag force. This further suppresses the movement of the electrode body and further reduces the influence of external forces on the current collection tab due to vibration, etc.

[0010] The secondary battery according to the above disclosure may further include a first conductive member which includes a first opposing portion facing the first end in the parallel direction and is connected to the first external terminal, and a second conductive member which includes a second opposing portion facing the second end in the parallel direction and is connected to the second external terminal. The tip end of each of the one or more first current collector tabs may be connected to the first opposing portion in a state in which they are folded back in an intersecting direction that intersects the parallel direction so as to include portions facing each other in the parallel direction with a first gap in between. The tip end of each of the one or more second current collector tabs may be connected to the second opposing portion in a state in which they are folded back in the intersecting direction so as to include portions facing each other in the parallel direction with a second gap in between. The first member may be placed in the first gap. The second member may be placed in the second gap.

[0011] With the above configuration, when a tensile force acts on one side of the first current collector tab and the second current collector tab in the direction of electrode movement as the electrode body moves in a parallel direction parallel to the cylindrical axis, the spacer can act as a counterforce against this tensile force at the connection between the first current collector tab and the first opposing part, or at the connection between the second current collector tab and the second opposing part. This makes it possible to more effectively suppress the influence of external forces on the current collector tab due to vibration, etc. [Effects of the Invention]

[0012] According to this disclosure, it is possible to provide a secondary battery that can suppress the influence of external forces on the current collector tab. [Brief explanation of the drawing]

[0013] [Figure 1] This is a perspective view of a secondary battery according to an embodiment. [Figure 2] This is a disassembled perspective view of a secondary battery according to an embodiment. [Figure 3] Figure 1 is a cross-sectional view of a secondary battery along the line III-III shown. [Figure 4] Figure 1 is a cross-sectional view of a secondary battery along the IV-IV line. [Figure 5]Figure 3 is a cross-sectional view of a secondary battery along the VV line. [Modes for carrying out the invention]

[0014] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the embodiments described below, the same or common parts are denoted by the same reference numerals in the drawings, and their descriptions will not be repeated.

[0015] Figure 1 is a perspective view of a secondary battery according to an embodiment. Figure 2 is an exploded perspective view of a secondary battery according to an embodiment. Figure 3 is a cross-sectional view of a secondary battery along the line III-III shown in Figure 1. The secondary battery 10 according to an embodiment will be described with reference to Figures 1 to 3.

[0016] As shown in Figures 1 to 3, the secondary battery 10 according to Embodiment 1 comprises an electrode body 100, a housing 200, a negative electrode member 520 as one external terminal, a positive electrode member 620 as the other external terminal, and a spacer 40.

[0017] The electrode body 100 has a first end 101 located on one side of the housing 200 in the width direction W, and a second end 102 located on the other side of the width direction W. The width direction W is parallel to the cylindrical axis direction of the cylindrical member 210, which will be described later. The first end 101 is provided with one or more first current collecting tabs, which are a plurality of negative electrode tabs 110N. The second end 102 is provided with one or more second current collecting tabs, which are a plurality of positive electrode tabs 110P. Note that the negative electrode tabs 110N and positive electrode tabs 110P may be singular. The detailed configuration of the electrode body 100 will be described later with reference to Figure 4.

[0018] The housing 200 has a rectangular parallelepiped shape with a thickness in the thickness direction T smaller than the width in the width direction W and the height in the height direction H. The thickness direction T is parallel to the parallel direction in which the positive electrode 110 (see FIG. 4) and the negative electrode 120 (see FIG. 4) described later are arranged side by side. The width direction W is orthogonal to the thickness direction T. The height direction H is orthogonal to the thickness direction T and the width direction W. The width of the housing 200 in the width direction W is larger than the height of the housing 200 in the height direction H.

[0019] The housing 200 houses the electrode body 100 and an electrolytic solution (not shown) inside. The housing 200 includes a cylindrical member 210 for housing the electrode body 100, a first sealing body 510 and a second sealing body 610 as a pair of sealing bodies.

[0020] In the cylindrical member 210, a pair of openings provided on both sides in the cylinder axis direction are provided. The pair of openings includes a first opening 215 and a second opening 216. The first opening 215 is provided on one side in the width direction W, and the second opening 216 is provided on the other side in the width direction W. The cylindrical member 210 is made of a metal such as aluminum.

[0021] A spacer 40 is disposed inside the cylindrical member 210. The spacer 40 is made of, for example, an insulating member. The spacer 40 may have elasticity. The spacer 40 includes a first member 41 and a second member 42 described later. The spacer 40 (each of the first member 41 and the second member 42) may be made of a foam of polyethylene or polypropylene, styrene rubber, ethylene - propylene rubber, or the like. The first member 41 and the second member 42 may have, for example, a leaf spring shape.

[0022] The first sealing body 510 closes 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, for example, laser welding or the like.

[0023] The second sealing body 610 closes 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, for example, laser welding.

[0024] Each of the first sealing body 510 and the second sealing body 610 is provided with a pressure relief valve 222 and an injection port 224. The pressure relief valve 222 is designed to rupture when the internal pressure of the housing 200 exceeds a predetermined pressure. When the pressure relief valve 222 ruptures, the gas inside the housing 200 is discharged to the outside of the housing 200, causing the internal pressure inside the housing 200 to decrease.

[0025] The electrolyte injection port 224 is sealed by a sealing member 225. The electrolyte injection port 224 is a through-hole for injecting electrolyte into the housing 200 during the manufacturing process of the secondary battery 10. The electrolyte injection port 224 is sealed by a sealing member 225. The sealing member 225 is a member that seals the electrolyte injection port 224 after the electrolyte has been injected into the housing 200. The sealing member 225 may be, for example, a permeable membrane 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 housing 200, the gas can be discharged through the permeable membrane. This eliminates the need to provide a separate gas vent. In addition, the permeable membrane can prevent the electrolyte from leaking to the outside of the housing 200. Note that the sealing member 225 is not limited to a permeable membrane, and resin members, metal members, etc. can be used as appropriate.

[0026] The first sealing body 510 is provided with a negative electrode member 520, and the second sealing body 610 is provided with a positive electrode member 620.

[0027] 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.

[0028] The negative electrode terminal plate 521 is formed in a substantially rectangular parallelepiped shape. The negative electrode 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 electrode terminal plate 521. Both the negative electrode terminal plate 521 and the insulating plate 522 are provided with through holes for inserting the first connecting portion 532, which will be described later.

[0029] 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.

[0030] The positive terminal plate 621 is formed in a rectangular parallelepiped shape. The positive terminal plate 621 is made of a metal such as aluminum.

[0031] The terminal block 622 is formed in a rectangular parallelepiped shape. The terminal block 622 is made of a different metal (such as iron) than the metal that makes up 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 cylindrical 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 with the same polarity as the positive terminal plate 621. Each of the positive terminal plate 621 and the terminal block 622 has a through hole for inserting the second connecting portion 632, which will be described later.

[0032] Furthermore, the positive electrode member 620 may have an insulating plate placed between it and the second sealing body 610, thereby electrically insulating the positive electrode member 620 from the second sealing body 610. In this case, the insulating plate may be placed in place of the terminal block 622, or the insulating plate may be placed between the terminal block 622 and the second sealing body 610.

[0033] The secondary battery 10 further includes a first conductive member 530 and an insulator 560 on the negative electrode member 520 side.

[0034] The first conductive member 530 connects a plurality of negative electrode tabs 110N and a negative electrode terminal plate 521. The plurality of negative electrode tabs 110N are connected to the first conductive member 530 in a bundled state by ultrasonic welding or the like. The first conductive member 530 has, for example, a first opposing portion 531 and a first connecting portion 532. The first opposing portion 531 has a plate-like shape. The first opposing portion 531 is substantially parallel to the inner surface of the first sealing body 510. The first opposing portion 531 faces the first end 101 of the electrode body 100 in the width direction W. The first connecting portion 532 extends along a direction parallel to the first direction. The first connecting portion 532 has, for example, a cylindrical shape. The tip of the first connecting portion 532 penetrates the first sealing body 510, the insulating plate 522, and the negative electrode terminal plate 521, and is crimped to the negative electrode terminal plate 521.

[0035] The insulator 560 is positioned between the first opposing portion 531 and the first sealing body 510, and insulates the first opposing portion 531 from the first sealing body 510. The insulator 560 includes a portion that covers the periphery of the base end side of the first connecting portion 532 and a portion that is located between the first opposing portion 531 and the inner surface of the first sealing body 510.

[0036] The negative electrode member 520, the first sealing body 510, the first conductive member 530, and the insulator 560 are assembled to constitute the first lid assembly 50.

[0037] The first lid assembly 50 is fixed to the cylindrical member 210 by attaching the first sealing body 510 to the first opening 215 with the multiple negative electrode tabs 110N and the first conductive member 530 fixed together by welding or the like.

[0038] The secondary battery 10 further includes a second conductive member 630 and an insulator 660 on the positive electrode member 620 side.

[0039] The second conductive member 630 connects a plurality of positive electrode tabs 110P and a positive electrode terminal plate 621. The plurality of positive electrode tabs 110P are connected to the second conductive member 630 in a bundled state by ultrasonic welding or the like. The second conductive member 630 includes a second opposing portion 631 and a second connecting portion 632. The second opposing portion 631 has a plate-like shape. The second opposing portion 631 is substantially parallel to the inner surface of the second sealing body 610. The second opposing portion 631 faces the second end 102 of the electrode body 100 in the width direction W. The second connecting portion 632 extends along a direction parallel to the first direction. The second connecting portion 632 has, for example, a cylindrical shape. The tip of the second connecting portion 632 penetrates the second sealing body 610, the terminal block 622 and the positive electrode terminal plate 621 and is crimped to the positive electrode terminal plate 621.

[0040] The insulator 660 is positioned between the second opposing portion 631 and the second sealing body 610, and insulates the second opposing portion 631 from the second sealing body 610. The insulator 660 includes a portion that covers the periphery of the base end side of the second connecting portion 632 and a portion that is located between the second opposing portion 631 and the inner surface of the second sealing body 610.

[0041] The positive electrode member 620, the second sealing body 610, the second conductive member 630, and the insulator 660 are assembled to form the second lid assembly 60.

[0042] The second lid assembly 60 is fixed to the cylindrical member 210 by attaching the second sealing body 610 to the second opening 216 with the multiple positive electrode tabs 110P and the second conductive member 630 fixed together by welding or the like.

[0043] Figure 4 is a cross-sectional view of the secondary battery along the IV-IV line shown in Figure 1. Referring to Figure 4, the detailed configuration of the electrode body of the secondary battery will be explained. For convenience, in Figure 4, the housing 200 of the secondary battery 10 is omitted, and only the electrode body 100 is shown. Referring to Figure 4, the details of the electrode body 100 will be explained.

[0044] As shown in Figure 4, the electrode body 100 comprises a plurality of positive electrodes 110 and a plurality of negative electrodes 120, and a separator 130. The plurality of positive electrodes 110 and a plurality of negative electrodes 120 are arranged alternately in the thickness direction T, insulated by the separator 130.

[0045] Each negative electrode 120 is formed in a rectangular shape with the width direction W as the long side and the height direction H as the short side. Each negative electrode 120 has a negative electrode current collector foil 122 and a negative electrode active material layer 124 provided on both sides of the negative electrode current collector foil 122. As shown in Figure 4, the negative electrode current collector foil 122 has 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.

[0046] Each positive electrode 110 is formed in a rectangular shape with the width direction W as the long side and the height direction H as the short side. Each positive electrode 110 has a positive electrode current collector foil 112 and a positive electrode active material layer 114 provided on both sides of the positive electrode current collector foil 112 in the thickness direction T. The positive electrode current collector foil 112 has 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.

[0047] The separator 130 insulates the positive electrode 110 and the negative electrode 120. The separator 130 is made of an insulating material and has minute voids that allow ion permeation. The separator 130 is formed in a zigzag pattern.

[0048] The separator 130 has a rectangular shape before being formed into a zigzag shape. The separator 130 is arranged between the positive electrode 110 and the negative electrode 120 while being formed into a zigzag shape. The separator 130 has a plurality of intervening portions 132a, a plurality of first folded portions 132b, a plurality of second folded portions 132c, and an outermost covering portion 132d.

[0049] Each intervening portion 132a is interposed between the positive electrode 110 and the negative electrode 120, which are adjacent to each other in the thickness direction T. In other words, each intervening portion 132a has the function of insulating the positive electrode 110 and the negative electrode 120. Each intervening portion 132a is composed of a rectangular region.

[0050] Each first folded portion 132b connects the ends of adjacent intervening portions 132a in the height direction H in the thickness direction T, such that the positive electrode 110 is positioned between them. The first folded portion 132b is positioned on one side (above) of the positive electrode 110 in the height direction H.

[0051] Each second folded portion 132c connects the other ends in the height direction H of adjacent intervening portions 132a in the thickness direction T, such that the negative electrode 120 is positioned between them. The second folded portion 132c is positioned on the other side (below) of the negative electrode 120 in the height direction H.

[0052] The outermost covering portion 132d covers each of the first folded portions 132b and each of the second folded portions 132c together. More specifically, the outermost covering portion 132d covers all of the positive electrodes 110, all of the negative electrodes 120, all of the intervening portions 132a, all of the first folded portions 132b and all of the second folded portions 132c together by winding them around a central axis parallel to the width direction W. The end portion 132e of the outermost covering portion 132d is set in 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 this embodiment, the end portion 132e of the outermost covering portion 132d is provided below each of the positive electrodes 110 and each of the negative electrodes 120. Note that the circumferential and bottom surfaces of the multiple positive electrodes 110, multiple negative electrodes 120, and the separator 130 may be covered with an insulating film (not shown).

[0053] Figure 5 is a cross-sectional view of the secondary battery along the VV line shown in Figure 3. Referring to Figure 5, the details of the connection configuration of the first member 41 and the second member 42 constituting the spacer 40, as well as the multiple negative electrode tabs 110N and the multiple positive electrode tabs 110P, will be described.

[0054] Multiple negative electrode tabs 110N are folded back in a direction intersecting the width direction W, with a first gap G1 in between, and their tip ends are connected to the first opposing portion 531. The tip end of the negative electrode tab 110N is on the opposite side from where the first end portion 101 is located. Multiple negative electrode tabs 110N are folded back in a roughly U-shape.

[0055] Multiple positive electrode tabs 110P are folded back in a direction intersecting the width direction W, with a second gap G2 in between, and their tip ends are connected to the second opposing portion 631. The tip end of the positive electrode tab 110P is on the opposite side from where the second end portion 102 is located. Multiple positive electrode tabs 110P are folded back in a roughly U-shape.

[0056] The first member 41 is positioned between the first sealing body 510 and the first end 101 of the electrode body 100. Specifically, it is positioned in the first gap G1. The second member 42 is positioned between the second sealing body 610 and the second end 102 of the electrode body 100. Specifically, it is positioned in the second gap G2.

[0057] As described above, by providing the first member 41 and the second member 42 as spacers 40, when an external force is applied to the electrode body 100 that moves it in a direction parallel to the cylindrical axis direction (width direction W) due to vibration or the like, the first member 41 or the second member 42 can act as a counterforce in the opposite direction to the direction of movement of the electrode body 100. This suppresses the movement of the electrode body 100 and prevents one of the negative electrode tab 110N and the positive electrode tab 110P from being pulled as the electrode body 100 moves. As a result, the influence of external forces on the electrode body 100 due to vibration or the like can be suppressed.

[0058] Furthermore, because the first member 41 and the second member 42 are elastic, an elastic force can be applied to the electrode body 100 in addition to the above-mentioned resistance force. This further suppresses the movement of the electrode body 100 and further suppresses the influence of external forces on the current collecting tab due to vibration, etc.

[0059] In addition, as described above, by arranging 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 direction of movement of the electrode body 100 due to vibration or the like, the first member 41 and the second member 42 can act as a counterforce against the tensile force at the connection between the negative electrode tab 110N and the first opposing part 531, or at the connection between the positive electrode tab 110P and the second opposing part 631. This makes it possible to more effectively suppress the influence of external forces on the current collector tab due to vibration or the like.

[0060] The embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, and all modifications are within the meaning and scope equivalent to the claims. [Explanation of Symbols]

[0061] 10 Secondary battery, 40 Spacer, 41 First component, 42 Second component, 50 First lid assembly, 60 Second lid assembly, 100 Electrode body, 101 First end, 102 Second end, 110 Positive electrode, 110N Negative electrode tab, 110P Positive electrode tab, 112 Positive electrode current collector foil, 114 Positive electrode active material layer, 120 Negative electrode, 122 Negative electrode current collector foil, 124 Negative electrode active material layer, 130 Separator, 132a Intervening part, 132b First folded part, 132c Second folded part, 132d Outermost covering part, 132e End, 200 Housing, 210 Cylindrical member, 215 First opening, 216 Second opening, 222 Pressure relief valve, 224 Liquid port, 225 Sealing member, 510 First sealing body, 520 Negative electrode member, 521 negative electrode terminal plate, 522 insulating plate, 530 first conductive member, 531 first opposing part, 532 first connecting part, 560 insulator, 610 second sealing body, 620 positive electrode member, 621 positive electrode terminal plate, 622 terminal block, 630 second conductive member, 631 second opposing part, 632 second connecting part, 660 insulator, G1 first gap, G2 second gap, H height direction, T thickness direction, W width direction.

Claims

1. Electrode body and A cylindrical member for housing the electrode body, A pair of sealing bodies that close a pair of openings provided on both sides of the cylindrical member in the direction of the cylindrical axis, A first external terminal is provided on one of the pair of sealing bodies, A second external terminal is provided on the other sealing body of the pair of sealing bodies, The cylindrical member comprises a spacer disposed inside the cylindrical member, The electrode body has a first end located on one side in a parallel direction parallel to the cylindrical axis and a second end located on the other side in the parallel direction, The first end is provided with one or more first current collector tabs electrically connected to the first external terminal, The second end is 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. The electrode body has a horizontally elongated shape in which the width in the parallel direction is longer than the height direction perpendicular to the parallel direction. The cylindrical member has a width in the parallel direction that is longer than the height direction. Each of the aforementioned sealing bodies is provided with an injection port. Each of the aforementioned liquid injection ports is sealed by a sealing member. A secondary battery in which each of the first and second members has a leaf spring shape.

2. The secondary battery according to claim 1, wherein the spacer is elastic.

3. A first conductive member, which includes a first opposing portion facing the first end in the parallel direction and connected to the first external terminal, The second conductive member further includes a second opposing portion facing the second end in the parallel direction and connected to the second external terminal, The one or more first current collector tabs are folded back in a direction intersecting the parallel direction so as to include portions facing each other in the parallel direction with a first gap between them, and their tip ends are connected to the first opposing portions. The one or more second current collector tabs are folded back in the intersecting direction so as to include portions facing each other in the parallel direction with a second gap between them, and their tip ends are connected to the second opposing portions. The first member is positioned in the first gap, The secondary battery according to claim 1 or 2, wherein the second member is disposed in the second gap.

4. The secondary battery according to claim 1 or 2, wherein the sealing member is composed of a permeable membrane that allows gas to pass through but not liquid.

5. The first external terminal includes a negative terminal plate that is electrically insulated from the one sealing body. The secondary battery according to claim 1 or 2, wherein the second external terminal includes a metal terminal block fixed to the outer surface of the other sealing body and a positive terminal plate made of a metal different from the metal constituting the terminal block.

6. The secondary battery according to claim 5, wherein the cylindrical member and the other sealing body are electrically connected to the positive terminal plate via the terminal block.

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