Secondary batteries

Abstract

A secondary battery capable of suppressing damage to an electrode body is provided. The secondary battery comprises: The battery includes an electrode assembly 100 having one or more negative electrode tabs 110N formed at a first end 111 and one or more positive electrode tabs 110P formed at a second end 112, a housing that houses the electrode assembly 100, and a negative electrode terminal 520 and a positive electrode terminal 620 provided in the housing, the housing including a cylindrical main body 210, a first sealing body 510, and a second sealing body 610, the negative electrode terminal 520 is provided in the first sealing body 510, the positive electrode terminal 620 is provided in the second sealing body 610, the one or more negative electrode tabs 110N are electrically connected to the negative electrode terminal 520, and the one or more positive electrode tabs 110P are electrically connected to the positive electrode terminal 620, and one of the one or more negative electrode tabs 110N and the one or more positive electrode tabs 110P is longer in length than the other of the one or more negative electrode tabs 110N and the one or more positive electrode tabs 110P.

Description

Technical Field

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

Background Art

[0002] As a conventional secondary battery, in US Patent Application Publication No. 2022 / 0302533 (Patent Document 1), a configuration is disclosed in which each opening of a case body having openings on both longitudinal sides in a housing for accommodating an electrode body is closed by a lid member provided with external terminals.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the secondary battery disclosed in Patent Document 1, after forming a lid assembly by pre-assembling external terminals and a current collector to the lid member, an electrode tab provided on the electrode body is fixed to the current collector of the lid assembly. Subsequently, with the electrode tab fixed to the current collector, the opening of the case body is closed with the lid assembly.

[0005] Specifically, first, on one side in the longitudinal direction, an electrode tab (for example, a positive electrode tab) of the electrode body is connected to the current collector of the lid assembly, and the opening of the case body is closed with the lid assembly. Subsequently, on the other side in the longitudinal direction, an electrode tab (for example, a negative electrode tab) of the electrode body is connected to the current collector of the lid assembly, and the opening of the case body is closed with the lid assembly.

[0006] Depending on how the current collector and electrode tab are fixed together on one side in the longitudinal direction, there is a concern that the electrode tab may be pulled and fixed to the current collector on the other side in the longitudinal direction. In this case, if no countermeasures are taken, the entire electrode body may be pulled, which could lead to damage to the electrode body.

[0007] 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 damage to the electrode body. [Means for solving the problem]

[0008] The secondary battery based on this disclosure is 2nd direction The first end located on one side and the above 2nd direction The device comprises an electrode body having a second end located on the other side of the first end, with one or more negative electrode tabs formed on the first end and one or more positive electrode tabs formed on the second end; a housing for housing the electrode body; and negative electrode terminals and positive electrode terminals provided on the housing. 2nd direction A first opening is provided on one side of the above and 2nd direction The device includes a cylindrical body portion having a second opening on the other side, a first sealing body that closes the first opening, and a second sealing body that closes the second opening. The negative terminal is provided on the first sealing body. The positive terminal is provided on the second sealing body. One or more negative tabs are electrically connected to the negative terminal. One or more positive tabs are electrically connected to the positive terminal. One of the one or more negative tabs and one or more positive tabs is longer in length than the other of the one or more negative tabs and one or more positive tabs.

[0009] According to the above configuration, one of the positive electrode tabs and the negative electrode tab is electrically connected to one of the positive electrode terminals and the negative electrode terminal, which has the same polarity as the one electrode tab. The other electrode tab is electrically connected to the other of the positive electrode terminal and the negative electrode terminal. The one external terminal is provided in one of the first sealing body and the second sealing body. The other external terminal is provided in the other sealing body. The one sealing body closes one of the first opening and the second opening. The other sealing body closes the other of the first opening and the second opening.

[0010] When assembling the secondary battery, the other electrode tab is electrically connected to the other external terminal and the other sealing body closes the other opening on the main body. Then, the one electrode tab is electrically connected to the one external terminal and the one sealing body closes the one opening on the main body. In this case, as described above, one electrode tab is longer than the other electrode tab. This allows the degree of slack in one electrode tab to be adjusted while assembling the one sealing body into the one opening. As a result, the force applied to the electrode body can be suppressed, and damage to the electrode body can be prevented.

[0011] In the secondary battery based on the above disclosure, one of the one or more negative electrode tabs and one or more positive electrode tabs may be more slack than the other of the one or more negative electrode tabs and one or more positive electrode tabs.

[0012] With the above configuration, one electrode tab sags more than the other electrode tab, which allows for more reliable suppression of the force applied to the electrode body.

[0013] In the secondary battery based on the above disclosure, the main body is the above 2nd direction orthogonal to 1st direction It has a first wall portion and a second wall portion facing the above. The first wall portion is the 1st directionIt is located on one side of the above. The second wall portion is the above 1st direction It is located on the other side. The electrode body is the same as above 1st direction The third end located on one side of the above and the above 1st direction It has a fourth end located on the other side. In this case, one of the one or more negative electrode tabs and one or more positive electrode tabs may include a portion that is sagging closer to the first wall than the third end, or a portion that is sagging closer to the second wall than the fourth end.

[0014] With the above configuration, a large adjustment range can be secured for the degree of slack in one of the electrode tabs. Therefore, the electrode body can be electrically connected stably to the positive and negative terminals.

[0015] In the secondary battery based on the above disclosure, the other of the one or more negative electrode tabs and the one or more positive electrode tabs is the above 1st direction In this configuration, the third end portion may be provided in such a way that it does not protrude toward the first wall portion, and the fourth end portion may be provided in such a way that it does not protrude toward the second wall portion.

[0016] According to the above configuration, the degree of sagging of the other tab can be reduced, and contact between the other tab and the housing can be suppressed.

[0017] The secondary battery according to the above disclosure may further include an insulating member disposed between the housing and the slack portion of one or more negative electrode tabs and one or more positive electrode tabs, wherein the slack portion insulates the housing.

[0018] According to the above configuration, by insulating the slack portion from the housing with an insulating material, electrical conductivity between one of the electrode tabs and the housing can be suppressed. [Effects of the Invention]

[0019] According to this disclosure, it is possible to provide a secondary battery that can suppress damage to the electrode body. [Brief explanation of the drawing]

[0020] [Figure 1] It is a perspective view of a secondary battery according to Embodiment 1. [Figure 2] It is an exploded perspective view of a secondary battery according to Embodiment 1. [Figure 3] It is a cross-sectional view taken along line III-III shown in FIG. 1. [Figure 4] It is a cross-sectional view taken along line IV-IV shown in FIG. 1. [Figure 5] It is a cross-sectional view of a secondary battery showing the connection state of the positive electrode tab and the negative electrode tab according to Embodiment 1. [Figure 6] It is a cross-sectional view of a secondary battery showing the connection state of the positive electrode tab and the negative electrode tab according to Embodiment 2. [Figure 7] It is a cross-sectional view of a secondary battery showing the connection state of the positive electrode tab and the negative electrode tab according to Embodiment 3.

Mode for Carrying Out the Invention

[0021] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the embodiments shown below, the same or common parts are denoted by the same reference numerals in the drawings, and the description thereof will not be repeated.

[0022] (Embodiment 1) FIG. 1 is a perspective view of a secondary battery according to Embodiment 1. FIG. 2 is an exploded perspective view of the secondary battery according to Embodiment 1. FIG. 3 is a cross-sectional view taken along line III-III shown in FIG. 1.

[0023] As shown in FIGS. 1 to 3, the secondary battery 10 according to Embodiment 1 includes an electrode body 100, a housing 200, a positive electrode member 620 as a positive electrode terminal, and a negative electrode member 520 as a negative electrode terminal.

[0024] The electrode body 100 2nd direction has a first end portion 101 located on one side of 2nd direction and a second end portion 102 located on the other side of 2nd directionThis direction is parallel to the width direction W, which will be described later. Multiple negative electrode tabs 110N are provided at the first end 101. Multiple positive electrode tabs 110P are provided at the second end 102.

[0025] The electrode body 100 is 2nd direction orthogonal to 1st direction The third end 103 located on one side, 1st direction It has a fourth end portion 104 located on the other side. 1st direction This direction is parallel to the thickness direction T, which will be described later. The detailed configuration of the electrode body 100 will be described later with reference to Figure 4.

[0026] The housing 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 parallel to the direction in which the positive electrode 110 (see Figure 4) and negative electrode 120 (see Figure 4), described later, are arranged side by side. The width direction W is perpendicular to the thickness direction T. The height direction H is perpendicular to both the thickness direction T and the width direction W. The width of the housing 200 in the width direction W is greater than the height of the housing 200 in the height direction H, with the width direction W being the longitudinal direction of the housing 200 and the height direction H being the short direction of the housing 200.

[0027] The housing 200 houses the electrode body 100 and the electrolyte (not shown) inside. The housing 200 includes a main body 210, a first sealing body 510, and a second sealing body 610.

[0028] The main body 210 has a cylindrical shape with a first opening 215 and a second opening 216 on both sides in the width direction W. More specifically, the main body 210 has a rectangular cylindrical shape with openings on both sides in the width direction W. 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 main body 210 is made of a metal such as aluminum.

[0029] The main body 210 includes a first wall portion 211 and a second wall portion 212 facing each other in the thickness direction T, and a third wall portion 213 and a fourth wall portion 214 facing each other in the height direction H. The area of ​​the first wall portion 211 and the second wall portion 212 is larger than that of the third wall portion 213 and the fourth wall portion 214.

[0030] The first wall portion 211 is positioned opposite the third end portion 103 of the electrode body 100, and the second wall portion 212 is positioned opposite the fourth end portion 104 of the electrode body 100. The third wall portion 213 is located on one side (upper side) in the height direction H. The third wall portion 213 connects the ends of the first wall portion 211 and the second wall portion 212, which are located on one side in the height direction H. The fourth wall portion 214 is located on the other side (downward side) in the height direction H. The fourth wall portion 214 connects the ends of the first wall portion 211 and the second wall portion 212, which are located on the other side in the height direction H.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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 cylindrical portion 532, which will be described later.

[0038] 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.

[0039] 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.

[0040] 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 main body 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 cylindrical portion 632, which will be described later.

[0041] 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.

[0042] The secondary battery 10 further includes a negative electrode side conductive member 530 and an insulator 560 on the negative electrode member 520 side.

[0043] The negative electrode side conductive member 530 connects the multiple negative electrode tabs 110N and the negative electrode terminal plate 521. The multiple negative electrode tabs 110N are connected to the negative electrode side conductive member 530 in a bundled state by ultrasonic welding or the like. The negative electrode side conductive member 530 includes a plate-shaped portion 531 and a cylindrical portion 532. The plate-shaped portion 531 is substantially parallel to the inner surface of the first sealing body 510. The cylindrical portion 532 is 2nd direction It extends along a direction parallel to the direction. The tip of the cylindrical 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.

[0044] The insulator 560 is positioned between the plate-shaped portion 531 and the first sealing body 510, and insulates the plate-shaped 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 cylindrical portion 532 and a portion that is located between the plate-shaped portion 531 and the inner surface of the first sealing body 510.

[0045] The negative electrode member 520, the first sealing body 510, the negative electrode side conductive member 530, and the insulator 560 are assembled to constitute the first lid assembly 50.

[0046] The first lid assembly 50 is fixed to the main body 210 by attaching the first sealing body 510 to the first opening 215 with the multiple negative electrode tabs 110N and the negative electrode side conductive member 530 fixed by welding or the like.

[0047] The secondary battery 10 further includes a positive electrode conductive member 630 and an insulator 660 on the positive electrode member 620 side.

[0048] The positive electrode side conductive member 630 connects the multiple positive electrode tabs 110P and the positive electrode terminal plate 621. The multiple positive electrode tabs 110P are connected to the positive electrode side conductive member 630 in a bundled state by ultrasonic welding or the like. The positive electrode side conductive member 630 includes a plate-shaped portion 631 and a cylindrical portion 632. The plate-shaped portion 631 is substantially parallel to the inner surface of the second sealing body 610. The cylindrical portion 632 is 2nd direction It extends along a direction parallel to the direction. The tip of the cylindrical portion 632 penetrates the second sealing body 610, the terminal block 622, and the positive terminal plate 621, and is crimped to the positive terminal plate 621.

[0049] The insulator 660 is positioned between the plate-shaped portion 631 and the second sealing body 610, and insulates the plate-shaped 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 cylindrical portion 632 and a portion that is located between the plate-shaped portion 631 and the inner surface of the second sealing body 610.

[0050] The positive electrode member 620, the second sealing body 610, the positive electrode side conductive member 630, and the insulator 660 are assembled to constitute the second lid assembly 60.

[0051] The second lid assembly 60 is fixed to the main body 210 by attaching the second sealing body 610 to the second opening 216 with the multiple positive electrode tabs 110P and the positive electrode side conductive member 630 fixed by welding or the like.

[0052] Figure 4 is a cross-sectional view along the line IV-IV shown in Figure 1. For convenience, the housing 200 of the secondary battery 10 is omitted in Figure 4, and only the electrode body 100 is shown. The details of the electrode body 100 will be explained with reference to Figure 4.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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).

[0062] Figure 5 is a cross-sectional view of a secondary battery showing the connection state of the positive electrode tab and negative electrode tab according to Embodiment 1. Figure 5 is a cross-sectional view along the VV line shown in Figure 3.

[0063] As shown in Figure 5, each of the multiple negative electrode tabs 110N is longer than each of the multiple positive electrode tabs 110P. The multiple negative electrode tabs 110N have a slack portion 110T. The multiple negative electrode tabs 110N are more slack than the multiple positive electrode tabs 110P.

[0064] Any of the multiple negative electrode tabs 110N includes a portion that sags so as to be closer to the first wall portion 211 than to the third end portion 103 of the electrode body 100.

[0065] Of the multiple negative electrode tabs 110N, the sagging portion 110T bulges in the bulging direction ( 1st direction (One side of) and the opposite side ( 1st direction The negative electrode tab 110N located on the other side is curved in a roughly U-shape. Specifically, the negative electrode tab 110N curves as it moves from the electrode body 100 toward the first sealing body 510. 1st direction Towards one side 1st direction It curves toward the other side.

[0066] Of the multiple negative electrode tabs 110N, the negative electrode tab 110N located on the side in the bulging direction is curved in a roughly S-shape. Specifically, as the negative electrode tab 110N approaches the first sealing body 510 from the electrode body 100, 1st direction It curves so as to bulge out on the other side, 1st direction It is curved in a way that it bulges out on one side.

[0067] On the other hand, all of the multiple positive electrode tabs 110P are 1st direction In the thickness direction T, it is provided so that it does not protrude from the third end 103 toward the first wall portion 211, and does not protrude from the fourth end 104 toward the second wall portion 212. Of the multiple positive electrode tabs 110P, 1st direction The positive electrode tab 110P located on the other side, as it moves from the electrode body 100 towards the second sealing body 610, 1st direction Towards one side 1st direction It is curved in a roughly U-shape toward the other side. Of the multiple positive electrode tabs 110P, 1st direction The positive electrode tab 110P located on one side moves from the electrode body 100 toward the second sealing body 610. 1st direction It curves toward the other side.

[0068] Thus, because the multiple negative electrode tabs 110N are longer than the multiple positive electrode tabs 110P, when assembling the first lid assembly 50 to the first opening 215 of the main body 210 after assembling the second lid assembly 60 to the second opening 216 of the main body 210, the slack of the multiple negative electrode tabs 110N can be adjusted while fixing the first sealing body 510 to the main body 210. This allows the electrode body 100 to be fixed overall when assembling the first lid assembly. 2nd direction This prevents pulling on one side (the side of the first opening 215). As a result, the force applied to the electrode body 100 can be suppressed, and damage to the electrode body 100 can be prevented.

[0069] Furthermore, because the multiple negative electrode tabs 110N sag more than the multiple positive electrode tabs 110P, the force applied to the electrode body 100 during the assembly of the first lid assembly 50 can be more reliably suppressed.

[0070] Furthermore, by including portions in which multiple negative electrode tabs 110N are slackened so as to be closer to the first wall portion 211 than to the third end portion 103, a large range of adjustment for the degree of slack can be ensured. This allows for a stable electrical connection between the electrode body 100 and the external terminal.

[0071] Furthermore, multiple positive electrode tabs 110P, 1st direction By ensuring that the positive electrode tab 110P does not protrude from the third end 103 toward the first wall portion 211, and does not protrude from the fourth end 104 toward the second wall portion 212, the degree of slack in the positive electrode tab 110P can be reduced. This prevents multiple positive electrode tabs 110P from coming into contact with the housing.

[0072] (Embodiment 2) Figure 6 is a cross-sectional view of a secondary battery showing the connection state of the positive electrode tab and negative electrode tab according to Embodiment 2. Specifically, Figure 6 is a cross-sectional view of the secondary battery according to Embodiment 2 at the position corresponding to Figure 5 described above.

[0073] As shown in Figure 6, the secondary battery 10A according to Embodiment 2 differs from the secondary battery 10 according to Embodiment 1 in that it includes an insulating member 80. The other configurations are substantially the same.

[0074] The insulating member 80 is positioned between the slack portion 110T and the housing 200. The insulating member 80 is positioned between the slack portion 110T and 1st direction It is positioned between the wall portion of the main body portion 210 and the sagging portion 110T, which face each other. In this embodiment, the insulating member 80 fills the gap between the sagging portion 110T and the first wall portion 211.

[0075] The insulating member 80 is provided so as to follow the slack portion 110T and has a support surface 81 that supports the slack portion 110T. The support surface 81 is, for example, a curved surface that curves in a U shape.

[0076] Even when configured as described above, the secondary battery 10A according to Embodiment 2 has substantially the same effect as the secondary battery 10 according to Embodiment 1.

[0077] In addition, the presence of the insulating member 80 prevents contact and electrical conductivity between the multiple negative electrode tabs 110N and the housing 200. Furthermore, the insulating member 80 has a support surface 81, which restricts the movement of the multiple negative electrode tabs 110N. This prevents the slack portion 110T from unintentionally coming into contact with the housing 200 and causing electrical conductivity.

[0078] (Embodiment 3) Figure 7 is a cross-sectional view of a secondary battery showing the connection state of the positive and negative electrode tabs according to Embodiment 3. Specifically, Figure 7 is a cross-sectional view of the secondary battery according to Embodiment 3 at the position corresponding to Figure 5 described above.

[0079] As shown in Figure 7, the secondary battery 10B according to Embodiment 3 differs from the secondary battery 10 according to Embodiment 1 mainly in the shape of the negative electrode conductive member 530 and the positive electrode conductive member 630. The other components are substantially the same.

[0080] The negative electrode conductive member 530 is positioned so as to face the first end 101 of the electrode body 100. 2nd direction It has a first extending portion 533 that extends along the line. The first extending portion 533 is 1st direction It is provided at the end of the plate-like portion 531 located on one side. The first extending portion 533 has an outer main surface facing the first wall portion 211, 1st direction It has an inner main surface located opposite to the outer main surface.

[0081] Multiple negative electrode tabs 110N are connected to the inner main surface of the first extension portion 533. Each of the multiple negative electrode tabs 110N has a curved portion that curves in an overall U-shape. The curved portion curves from the electrode body 100 toward the first sealing body 510. 1st directionIn this configuration, the first extended portion 533 is curved so as to initially move toward the opposite side from where it is located, and then move toward the side where the first extended portion 533 is located. The curved portion constitutes the slack portion of multiple negative electrode tabs 110N.

[0082] The positive electrode side conductive member 630 is positioned so as to face the second end 102 of the electrode body 100. 2nd direction It has a second extending portion 633 that extends along the line. The second extending portion 633 is 1st direction It is provided at the end of the plate-like portion 631 located on one side. The second extending portion 633 has an outer main surface facing the first wall portion 211, 1st direction It has an inner main surface located opposite to the outer main surface.

[0083] All of the negative electrode tabs 110N are 1st direction The third end portion 103 may be provided in such a way that it does not protrude toward the first wall portion 211 side, nor from the fourth end portion 104 toward the second wall portion 212 side, in the thickness direction T.

[0084] Multiple positive electrode tabs 110P are connected to the inner main surface of the second extension portion 633. The multiple positive electrode tabs 110P have less slack than the multiple negative electrode tabs 110N.

[0085] All of the multiple positive electrode tabs 110P are 1st direction The third end portion 103 may be provided in such a way that it does not protrude toward the first wall portion 211 side, nor from the fourth end portion 104 toward the second wall portion 212 side, in the thickness direction T.

[0086] Even when configured as described above, the secondary battery 10B according to Embodiment 3 has substantially the same effects as the secondary battery 10 according to Embodiment 1.

[0087] In the third embodiment, the first extended portion 533 and the second extended portion 633 are 1st direction The example given is that the extensions are provided at the ends of the plate-like portions 531 and 631 located on one side of the structure, but the explanation is not limited to this. The first extension portion 533 and the second extension portion 633 are 1st directionIt may also be provided at the ends of the plate-like portions 531 and 631 located on the other side.

[0088] (Other variations) In embodiments 1 to 3 described above, the case in which the multiple negative electrode tabs 110N are longer than the multiple positive electrode tabs 110P is illustrated, but the invention is not limited to this. The multiple positive electrode tabs 110P may also be longer than the multiple negative electrode tabs 110N. In this case, after assembling the first lid assembly 50 to the first opening 215 of the main body 210, when assembling the second lid assembly 60 to the second opening 216 of the main body 210, the second sealing body 610 can be fixed to the main body 210 while adjusting the degree of slack of the multiple positive electrode tabs 110P. This makes it possible to suppress the force applied to the electrode body 100 when assembling the second lid assembly 60, and to suppress damage to the electrode body 100.

[0089] Furthermore, in the above case, the multiple positive electrode tabs 110P may be more slack than the multiple negative electrode tabs 110N, and an insulating member 80 similar to that in Embodiment 2 may be placed between the slack portion of the multiple positive electrode tabs 110P and the housing 200.

[0090] In the embodiments 1 and 2 described above, examples were given in which the plurality of negative electrode tabs 110N include portions that sag so as to be closer to the first wall portion 211 than the third end portion 103 of the electrode body 100, but the invention is not limited to this. The plurality of negative electrode tabs 110N may also include portions that sag so as to be closer to the second wall portion 212 than the fourth end portion 104 of the electrode body 100. In this case as well, a large margin for adjusting the degree of sag can be secured, and the electrode body 100 and the external terminal can be electrically connected stably.

[0091] 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]

[0092] 10,10A,10B Secondary battery, 50 First lid assembly, 60 Second lid assembly, 80 Insulating member, 81 Support surface, 100 Electrode body, 101 First end, 102 Second end, 103 Third end, 104 Fourth end, 110 Positive electrode, 110N Negative electrode tab, 110P Positive electrode tab, 110T Slack portion, 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 portion, 132b First folded portion, 132c Second folded portion, 132d Outermost covering portion, 132e Termination, 200 Housing, 210 Main body portion, 211 First wall portion, 212 Second wall portion, 213 Third wall section, 214 Fourth wall section, 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 Negative electrode side conductive member, 531 Plate-shaped section, 532 Cylindrical section, 533 First extension section, 560 Insulator, 610 Second sealing body, 620 Positive electrode member, 621 Positive electrode terminal plate, 622 Terminal block, 630 Positive electrode side conductive member, 631 Plate-shaped section, 632 Cylindrical section, 633 Second extension section, 660 Insulator, H Height direction, T Thickness direction, W Width direction.

Claims

1. An electrode body comprising a plurality of positive and negative electrodes arranged alternately in a first direction, and a separator disposed between the positive and negative electrodes, The system comprises a housing for accommodating the electrode body, The aforementioned enclosure is A positive electrode terminal is provided, and a positive electrode side sealing body is positioned at one end of a second direction perpendicular to the first direction, A negative electrode terminal is provided, and a negative electrode side sealing body is located at the other end in the second direction, The electrode body is A positive electrode current collector tab is disposed at one end of the positive electrode in the second direction, The negative electrode includes a negative electrode current collector tab positioned at the other end of the negative electrode in the second direction, The positive electrode current collector tab is electrically connected to the positive electrode terminal via a positive electrode conductive member that is positioned through the positive electrode side sealing body. The negative electrode current collector tab is electrically connected to the negative electrode terminal via a negative electrode conductive member that is positioned through the negative electrode side sealing body. The aforementioned separator is, A plurality of first folded portions are folded back on the outside of the end of each positive electrode in a third direction perpendicular to both the first and second directions, The third direction includes a plurality of second folded portions that are folded back on the outside of each negative electrode end, The positive electrode current collector tab is longer than the negative electrode current collector tab. Viewed from the third direction, the positive electrode current collector tab includes a curved portion that, as it moves outward in the second direction, turns toward one side of the first direction and then toward the other side of the first direction. A secondary battery wherein an insulating member is disposed between the surface of the curved portion on one side in the first direction and the housing.

2. The secondary battery according to claim 1, wherein the electrode body is covered with an insulating film.

3. The positive electrode side sealing body is provided with an injection port located on one side of the positive electrode terminal in the third direction, The secondary battery according to claim 2, wherein, when viewed from the first direction, the center of the liquid injection port is located on the side of the third direction that is greater than the end of the positive electrode current collector tab on that side that side.

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