Secondary battery

Abstract

The invention provides a secondary battery. In a secondary battery, a main body portion of a case has a bottom surface portion, a first side surface portion, a second side surface portion, a first top surface portion, a second top surface portion, and a welded portion. The first top surface portion extends from an end portion of the first side surface portion opposite to the bottom surface portion toward the second side surface portion. The second top surface portion extends toward the first side surface portion from an end portion of the second side surface portion opposite to the bottom surface portion side. The welding portion connects a terminal edge of the first top surface portion and a terminal edge of the second top surface portion to each other.

Description

Technical Field

[0001] The present disclosure relates to a secondary battery. Background Art

[0002] Japanese Patent Application Laid-Open No. 2013-143332 discloses a battery in which a battery case and a cover are joined by forming a welded portion at abutting portions thereof. Summary of the invention

[0003] In order to improve the energy density of secondary batteries, it is required to enlarge the shell of secondary batteries. Here, in the battery disclosed in Japanese Patent Publication No. 2013-143332, an open end is formed on the upper side of the battery shell (shell). The cover is connected to the open end by welding. When the shell of such a battery is further enlarged in the width direction orthogonal to the height direction, the welding length of the open end is further lengthened. As a result, the welding strain of the shell can be further increased. Furthermore, the dimensional accuracy of the shell may be reduced.

[0004] The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide a secondary battery in which welding strain of a case is suppressed and dimensional accuracy of the case is improved.

[0005] The secondary battery based on the present disclosure comprises an electrode body and a shell. The shell accommodates the electrode body. The shell is configured such that the dimension in the width direction is longer than the dimension in the height direction and the dimension in the thickness direction. The thickness direction is orthogonal to the height direction. The width direction is orthogonal to both the height direction and the thickness direction. The shell comprises a main body, a first sealing body and a second sealing body. The main body has a cylindrical shape. The main body is provided with a first opening and a second opening at both ends in the width direction. The first sealing body blocks the first opening. The second sealing body blocks the second opening. The main body comprises a bottom face portion, a first side face portion, a second side face portion, a first top face portion, a second top face portion and a welding portion. The bottom face portion is located on one side in the height direction. The first side face portion rises from one end in the thickness direction of the bottom face portion along the height direction. The second side face portion rises from the other end in the thickness direction of the bottom face portion along the height direction. The first top face portion extends from the end of the first side face portion on the side opposite to the bottom face portion side toward the second side face portion. The second top face portion extends from the end of the second side face portion on the side opposite to the bottom face portion side toward the first side face portion. The welding portion connects the terminal edge of the first top surface portion and the terminal edge of the second top surface portion to each other.

[0006] According to the above structure, the end edges are welded to each other, so the welding length on the opposite side of the bottom surface can be shortened compared to the case where the shell has an opening on the opposite side of the bottom surface. Furthermore, the welding strain of the shell can be suppressed. Furthermore, the dimensional accuracy of the shell is improved.

[0007] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a perspective view of the secondary battery according to the first embodiment.

[0009] Figure 2 This is an exploded perspective view of the secondary battery according to the first embodiment.

[0010] Figure 3 It is along Figure 1 A cross-sectional view along line III-III is shown.

[0011] Figure 4 It is a top view of the secondary battery according to the first embodiment.

[0012] Figure 5A and Figure 5B This is a diagram schematically showing a process of molding the main body portion in the first embodiment.

[0013] Figure 6 It is along Figure 1 A cross-sectional view taken along line VI-VI is shown.

[0014] Figure 7 It is a top view of the secondary battery according to the second embodiment.

[0015] Fig. 8A and Figure 8B This is a diagram schematically showing a process of molding the main body portion in the second embodiment. DETAILED DESCRIPTION

[0016] The embodiments of the present disclosure will be described with reference to the accompanying drawings. In the drawings referred to below, the same or corresponding components are denoted by the same reference numerals.

[0017] (Implementation Method 1)

[0018] Figure 1 This is a perspective view of the secondary battery according to the first embodiment. Figure 2 This is an exploded perspective view of the secondary battery according to the first embodiment. Figure 3 It is along Figure 1 A cross-sectional view along line III-III is shown. Figure 4 It is a top view of the secondary battery according to the first embodiment.

[0019] like Figures 1 to 4 As shown, the secondary battery 10 of the first embodiment includes an electrode body 100 , a case 200 , a positive electrode member 620 as a positive electrode terminal, and a negative electrode member 520 as a negative electrode terminal.

[0020] The housing 200 has a substantially rectangular parallelepiped shape. The housing 200 is configured such that the dimension in the width direction W is longer than the dimension in the height direction H and the dimension in the thickness direction T. The thickness direction T is a direction orthogonal to the height direction H. In addition, the housing 200 is configured such that the dimension in the height direction H is longer than the dimension in the thickness direction T. The thickness direction T is a direction perpendicular to the positive electrode 110 and the negative electrode 120 (see Figure 6 ) is a direction parallel to the arrangement direction. The width direction W is a direction orthogonal to both the height direction H and the thickness direction T.

[0021] The case 200 accommodates the electrode body 100 and an electrolyte solution (not shown) therein. The case 200 includes a main body 210 , a first sealing body 510 , and a second sealing body 610 .

[0022] The main body 210 has a cylindrical shape with a first opening 218 and a second opening 219 provided on both sides in the width direction W. The first opening 218 is provided on one side in the width direction W, and the second opening 219 is provided on the other side in the width direction W. The main body 210 is made of metal such as aluminum.

[0023] The main body 210 includes a bottom surface portion 211 , a first side surface portion 212A, a second side surface portion 212B, a first top surface portion 213A, a second top surface portion 213B, and a welding portion 217 .

[0024] The bottom surface portion 211 is located on one side in the height direction H. The bottom surface portion 211 has a rectangular outer shape when viewed from the height direction H.

[0025] The first side surface portion 212A stands up from one end in the thickness direction T of the bottom surface portion 211 along the height direction H. The second side surface portion 212B stands up from the other end in the thickness direction T of the bottom surface portion 211 along the height direction H. When viewed from the thickness direction T, the first side surface portion 212A and the second side surface portion 212B have a rectangular shape. The first side surface portion 212A and the second side surface portion 212B may be inclined with respect to the height direction H. The first side surface portion 212A and the second side surface portion 212B may extend in a manner of approaching each other as they move away from the bottom surface portion 211.

[0026] The first top surface portion 213A extends from an end portion of the first side surface portion 212A on the opposite side to the bottom surface portion 211 toward the second side surface portion 212B.

[0027] The first top face portion 213A includes a first base portion 214A, a first inner side portion 215A, and a first terminal portion 216A. The first base portion 214A extends continuously from the first side portion 212A along the thickness direction T. The first inner side portion 215A extends from the first base portion 214A toward the bottom face portion 211. The first inner side portion 215A is inclined with respect to the height direction H. The first terminal portion 216A extends from the first inner side portion 215A along the thickness direction T and has a terminal edge of the first top face portion 213A.

[0028] The second top surface portion 213B extends from an end portion of the second side surface portion 212B on the opposite side to the bottom surface portion 211 toward the first side surface portion 212A.

[0029] The second top face portion 213B has a second base portion 214B, a second inner side portion 215B, and a second terminal portion 216B. The second base portion 214B extends continuously from the second side portion 212B along the thickness direction T. The second inner side portion 215B extends from the second base portion 214B toward the bottom face portion 211. The second inner side portion 215B is inclined with respect to the height direction H. The second terminal portion 216B extends from the second inner side portion 215B along the thickness direction T and has a terminal edge of the second top face portion 213B.

[0030] The welding portion 217 connects the terminal edge of the first top face portion 213A and the terminal edge of the second top face portion 213B to each other. That is, the welding portion 217 is formed by connecting the terminal edge of the first top face portion 213A and the terminal edge of the second top face portion 213B by welding. The welding method is not particularly limited, and it may be laser welding, for example. The welding portion 217 includes a weld bead formed by the above welding. The weld bead protrudes from the first top face portion 213A and the second top face portion 213B to the side opposite to the bottom face portion 211 side.

[0031] The welding portion 217 extends in only one direction along the width direction W. The welding portion 217 is located on the first terminal portion 216A and the second terminal portion 216B, and is located closer to the bottom surface portion 211 in the height direction H than the first base portion 214A and the second base portion 214B.

[0032] In addition, in this embodiment, the main body 210 has a plurality of welded portions 217 as the above-mentioned welded portions 217. The plurality of welded portions 217 are separated from each other. The plurality of welded portions 217 are arranged in the width direction W.

[0033] The main body 210 further includes a liquid injection port 224 and a sealing member 225. The sealing member 225 seals the liquid injection port 224. The liquid injection port 224 is a through hole for injecting electrolyte into the housing 200 during the manufacturing process of the secondary battery 10. The liquid injection port 224 is sealed by the sealing member 225. The sealing member 225 is a member that seals the liquid injection port 224 after the electrolyte is injected into the housing 200.

[0034] In this embodiment, the liquid injection port 224 is provided between the first terminal portion 216A and the second terminal portion 216B. The sealing member 225 is located closer to the bottom surface portion 211 than the first base portion 214A and the second base portion 214B in the height direction H. The hole shape of the liquid injection port 224 is not particularly limited, and is, for example, circular.

[0035] In this embodiment, the main body 210 has a plurality of injection ports 224 as the above-mentioned injection ports 224. Thus, by injecting the electrolyte from the plurality of injection ports 224, the electrolyte can be efficiently infiltrated into the separator 130 (see Figure 6 ) as a whole. From the viewpoint of improving the penetration of the electrolyte, it is preferred that at least one injection port 224 is arranged at a distance substantially equal to the distance from the negative electrode member 520 and the distance from the positive electrode member 620. In addition, it is preferred that at least one injection port 224 is also arranged at a position closer to the negative electrode member 520 than the positive electrode member 620. In addition, it is preferred that at least one injection port 224 is also arranged at a position closer to the positive electrode member 620 than the negative electrode member 520. The main body 210 preferably has three or more injection ports 224. In addition, from the viewpoint of reducing the cost of forming the injection ports 224 and preparing the sealing member 225, it is preferred that the number of injection ports 224 is smaller.

[0036] Here, a method of molding the main body 210 will be described. Figure 5A This is a plan view showing a plate-shaped member prepared for molding a main body portion in the first embodiment. Figure 5B 1 is a plan view showing the state immediately after the plate-like member is bent in Embodiment 1. Figure 5A and Figure 5B In the illustrated plate-shaped member 210P, portions corresponding to the respective structures of the main body 210 are denoted by the same reference numerals as those representing the respective structures of the main body 210 .

[0037] like Figure 5A As shown in FIG. 1 , the plate-like member 210P has a flat plate-like outer shape. Specifically, the plate-like member 210P is prepared by punching a thin plate made of aluminum. At this time, a plurality of cutouts corresponding to the liquid injection port 224 are formed in the plate-like member 210P.

[0038] Then, if Figure 5A and Figure 5BAs shown, the bottom face portion 211, the first side face portion 212A, the second side face portion 212B, the first top face portion 213A and the second top face portion 213B are formed by bending the plate-like member 210P at multiple locations. Therefore, the main body 210 can be easily formed into various sizes. In addition, the above-mentioned face portions can also be formed by roll forming the plate-like member 210P.

[0039] Then, the distal ends of the plate-like member 210P formed in this way are welded together, avoiding the notch corresponding to the liquid injection port 224, thereby forming a welded portion 217 (see FIG. Figure 4 ), forming the main body portion 210.

[0040] like Figures 1 to 3 As shown, the first sealing body 510 blocks the first opening 218. The first sealing body 510 has a flat plate shape. The first sealing body 510 is made of metal such as aluminum. A negative electrode component 520 is provided on the first sealing body 510. The first sealing body 510 is fixed to the first opening 218 by, for example, laser welding. A pressure release valve 515 is provided on the first sealing body 510. The pressure release valve 515 is provided in a manner that breaks when the internal pressure of the shell 200 becomes above a specified pressure. By breaking the pressure release valve 515, the gas in the shell 200 is discharged to the outside of the shell 200, so the internal pressure in the shell 200 is reduced. In addition, a negative electrode component 520 is provided on the first sealing body 510.

[0041] 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 .

[0042] 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. Through holes for inserting a negative electrode connecting pin 533 described later are respectively provided in the negative terminal plate 521 and the insulating plate 522.

[0043] The second sealing body 610 blocks the second opening 219. The second sealing body 610 has a flat plate shape. The second sealing body 610 is made of a metal such as aluminum. A positive electrode component 620 is provided on the second sealing body 610. The second sealing body 610 is fixed to the second opening 219 by, for example, laser welding. A pressure release valve 615 is provided on the second sealing body 610. The pressure release valve 615 is provided in a manner that breaks when the internal pressure of the housing 200 becomes above a specified pressure. By breaking the pressure release valve 615, the gas in the housing 200 is discharged to the outside of the housing 200, so the internal pressure in the housing 200 is reduced. In addition, a positive electrode component 620 is provided on the second sealing body 610.

[0044] 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 .

[0045] The positive electrode terminal plate 621 is formed in a rectangular parallelepiped shape and is made of metal such as aluminum.

[0046] 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 main body 210 and the second sealing body 610 are electrically connected to the positive terminal plate 621 via the terminal block 622, and carry electricity of the same polarity as the positive terminal plate 621. A through hole for inserting a positive electrode connecting pin 633 described later is formed in the positive terminal plate 621 and the terminal block 622, respectively.

[0047] Alternatively, 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 between the terminal block 622 and the second sealing body 610.

[0048] The secondary battery 10 further includes a negative electrode connecting member 530 , a negative electrode side first insulating member 540 , a negative electrode side second insulating member 550 , and an insulator 560 on the negative electrode member 520 side.

[0049] The negative electrode connecting member 530 connects the negative electrode current collecting portion 110N and the negative electrode terminal plate 521. The negative electrode current collecting portion 110N is a portion of the electrode body 100 formed by bundling a plurality of negative electrode tabs 122n described later. The negative electrode connecting member 530 includes a negative electrode side first current collector 531, a negative electrode side second current collector 532, and a negative electrode connecting pin 533.

[0050] The negative electrode side first current collector 531 is composed of a thin plate-shaped conductive member and is connected to the negative electrode current collecting portion 110N by laser welding, ultrasonic welding or the like.

[0051] The second current collector 532 on the negative electrode side is composed of a thin plate-shaped conductive member. The second current collector 532 on the negative electrode side is connected to the first current collector 531 on the negative electrode side by laser welding or ultrasonic welding. The second current collector 532 on the negative electrode side has a holding portion 532a for holding the negative electrode connecting pin 533. The holding portion 532a has a flat plate shape. A through hole is provided in the holding portion 532a for inserting the base end of the negative electrode connecting pin 533.

[0052] The negative electrode connecting pin 533 connects the negative electrode side second current collector 532 and the negative electrode terminal plate 521. The negative electrode connecting pin 533 includes a cylindrical portion. The end side of the cylindrical portion penetrates the first sealing body 510, the insulating plate 522 and the negative electrode terminal plate 521, and is riveted to the negative electrode terminal plate 521.

[0053] The negative electrode side first insulating member 540 has a substantially plate-like shape and is disposed so as to be in contact with the inner surface of the first sealing body 510. The negative electrode side first insulating member 540 is provided with a through hole 542 through which the negative electrode connecting pin 533 is inserted.

[0054] The negative electrode side second insulating member 550 is disposed between the negative electrode side first insulating member 540 and the electrode body 100. The negative electrode side second insulating member 550 is provided with a slit 552 through which the negative electrode current collecting portion 110N is inserted.

[0055] The negative electrode first insulating member 540 and the negative electrode second insulating member 550 are assembled to form a housing space therebetween. The negative electrode current collecting portion 110N inserted through the slit 552, the negative electrode first current collector 531, and the negative electrode second current collector 532 are arranged in the housing space.

[0056] The insulator 560 has a shape covering the cylindrical portion of the negative electrode connecting pin 533. The insulator 560 insulates the negative electrode connecting pin 533 from the case 200 (more specifically, the first sealing body 510).

[0057] The negative electrode member 520 , the first sealing body 510 , the negative electrode connecting member 530 , the negative electrode side first insulating member 540 , the negative electrode side second insulating member 550 , and the insulator 560 are assembled to form the first cap assembly 50 .

[0058] The first cap assembly 50 is fixed to the main body 210 by attaching the first sealing body 510 to the first opening 218 in a state where the negative electrode current collecting portion 110N and the negative electrode connecting member 530 are fixed by welding or the like.

[0059] The secondary battery 10 further includes a positive electrode connecting member 630 , a positive electrode side first insulating member 640 , a positive electrode side second insulating member 650 , and an insulator 660 on the positive electrode member 620 side.

[0060] The positive electrode connecting member 630 connects the positive electrode current collecting portion 110P to the positive electrode terminal plate 621. The positive electrode current collecting portion 110P is a portion of the electrode body 100 formed by bundling a plurality of positive electrode tabs 112p described later. The positive electrode connecting member 630 includes a positive electrode side first current collector 631, a positive electrode side second current collector 632, and a positive electrode connecting pin 633.

[0061] The first positive electrode current collector 631 is formed of a thin plate-shaped conductive member and is connected to the positive electrode current collecting portion 110P by laser welding, ultrasonic welding or the like.

[0062] The second current collector 632 on the positive electrode side is composed of a thin plate-shaped conductive member. The second current collector 632 on the positive electrode side is connected to the first current collector 631 on the positive electrode side by laser welding or ultrasonic welding. The second current collector 632 on the positive electrode side has a holding portion 632a for holding the positive electrode connecting pin 633. The holding portion 632a has a flat plate shape. A through hole is provided in the holding portion 632a for inserting the base end of the positive electrode connecting pin 633.

[0063] The positive electrode connecting pin 633 connects the positive electrode side second current collector 632 and the positive electrode terminal plate 621. The positive electrode connecting pin 633 includes a cylindrical portion. The end side of the cylindrical portion penetrates the second sealing body 610, the terminal block 622 and the positive electrode terminal plate 621, and is riveted to the positive electrode terminal plate 621.

[0064] The positive electrode side first insulating member 640 has a substantially plate-like shape and is disposed so as to be in contact with the inner surface of the second sealing body 610. The positive electrode side first insulating member 640 is provided with a through hole 642 through which the positive electrode connecting pin 633 is inserted.

[0065] The positive electrode side second insulating member 650 is disposed between the positive electrode side first insulating member 640 and the electrode body 100. The positive electrode side second insulating member 650 is provided with a slit 652 through which the positive electrode current collecting portion 110P is inserted.

[0066] The positive electrode first insulating member 540 and the positive electrode second insulating member 550 are assembled to form a storage space therebetween. The positive electrode current collecting portion 110P inserted through the slit 552, the positive electrode first current collector 631, and the positive electrode second current collector 632 are arranged in the storage space.

[0067] The insulator 660 has a shape covering the cylindrical portion of the positive electrode connecting pin 633. The insulator 660 insulates the positive electrode connecting pin 633 from the case 200 (more specifically, the second sealing body 610).

[0068] The positive electrode member 620 , the second sealing body 610 , the positive electrode connecting member 630 , the positive electrode side first insulating member 640 , the positive electrode side second insulating member 650 , and the insulator 660 are assembled to form the second cap assembly 60 .

[0069] The second cap assembly 60 is fixed to the main body 210 by attaching the second sealing body 610 to the second opening 219 in a state where the positive electrode current collecting portion 110P and the positive electrode connecting member 630 are fixed by welding or the like.

[0070] Figure 6 It is along Figure 1 The cross-sectional view of the line VI-VI is shown. Figure 6 In the figure, for convenience, the housing 200 of the secondary battery 10 is omitted, and only the electrode body 100 is shown. Figure 6 , the details of the electrode body 100 will be described.

[0071] like Figure 6 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 alternately arranged in the thickness direction T in a state in which they are insulated by the separator 130 .

[0072] 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 includes a negative electrode collector foil 122 and a negative electrode active material layer 124 provided on both sides of the negative electrode collector foil 122. The negative electrode collector foil 122 includes a negative electrode tab 122n (see Figure 3 ). The negative electrode tab 122n protrudes toward one side in the width direction W.

[0073] Each positive electrode 110 is formed into 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 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 112p (see Figure 3 ). The positive electrode tab 112p protrudes toward the other side in the width direction W.

[0074] The separator 130 insulates the positive electrode 110 from the negative electrode 120. The separator 130 is made of an insulating material and has minute gaps that allow ions to pass through. The separator 130 is formed in a zigzag shape.

[0075] The separator 130 has a rectangular shape before being formed into a zigzag shape. The separator 130 is formed and arranged in a zigzag shape between the positive electrode 110 and the negative electrode 120. 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.

[0076] Each intervening 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 intervening portion 132a has a function of insulating the positive electrode 110 and the negative electrode 120. Each intervening portion 132a is composed of a rectangular region.

[0077] Each first folded portion 132 b connects one end portion in the height direction H of the interposed portions 132 a adjacent to each other in the thickness direction T so that the positive electrode 110 is located therebetween. The first folded portion 132 b is disposed on one side in the height direction H of the positive electrode 110 (upper side).

[0078] Each second folded portion 132 c connects the other ends of the interposed portions 132 a 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 132 c is disposed on the other side (lower side) in the other direction of the height direction H of the negative electrode 120 .

[0079] The outermost covering portion 132d covers all the first folding portions 132b and all the second folding portions 132c. In more detail, the outermost covering portion 132d winds all the positive electrodes 110, all the negative electrodes 120, all the interposing portions 132a, all the first folding portions 132b, and all the second folding portions 132c around a central axis parallel to the width direction W and covers them together. The terminal 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 the present embodiment, the terminal 132e of the outermost covering portion 132d is set at a position lower than 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 the plurality of positive electrodes 110, the plurality of negative electrodes 120, and the separator 130.

[0080] As described above, in the secondary battery 10 of the first embodiment of the present disclosure, the main body 210 has a cylindrical shape. The main body 210 has a bottom face portion 211, a first side face portion 212A, a second side face portion 212B, a first top face portion 213A, a second top face portion 213B, and a welding portion 217. The bottom face portion 211 is located on one side of the height direction H. The first side face portion 212A stands up along the height direction H from one end in the thickness direction T of the bottom face portion 211. The second side face portion 212B stands up along the height direction H from the other end in the thickness direction T of the bottom face portion 211. The first top face portion 213A extends from the end of the first side face portion 212A on the side opposite to the bottom face portion 211 side toward the second side face portion 212B. The second top face portion 213B extends from the end of the second side face portion 212B on the side opposite to the bottom face portion 211 side toward the first side face portion 212A. The welding portion 217 connects the distal edge of the first top surface portion 213A and the distal edge of the second top surface portion 213B to each other.

[0081] According to the above structure, the welding length on the opposite side of the bottom surface portion 211 can be shortened compared to the case where the housing 200 has an opening on the opposite side of the bottom surface portion 211. Furthermore, it is possible to suppress welding strain of the housing 200. In particular, when the housing 200 has a long dimension in the width direction W, the welding length can be shortened more effectively.

[0082] In the present embodiment, the welded portion 217 extends only in one direction along the width direction W. According to this structure, the welded length can be further shortened, and the weld strain of the housing 200 can be further suppressed.

[0083] In the present embodiment, the first top face portion 213A includes a first base portion 214A, a first inner side portion 215A, and a first terminal portion 216A. The first base portion 214A extends continuously from the first side portion 212A along the thickness direction T. The first inner side portion 215A extends from the first base portion 214A toward the bottom face portion 211 side. The first terminal portion 216A extends from the first inner side portion 215A along the thickness direction T and has a terminal edge of the first top face portion 213A. The second top face portion 213B includes a second base portion 214B, a second inner side portion 215B, and a second terminal portion 216B. The second base portion 214B extends continuously from the second side portion 212B along the thickness direction T. The second inner side portion 215B extends from the second base portion 214B toward the bottom face portion 211 side. The second terminal portion 216B extends from the second inner side portion 215B along the thickness direction T and has a terminal edge of the second top face portion 213B. The welding portion 217 is located on the first terminal portion 216A and the second terminal portion 216B, and is located closer to the bottom surface portion 211 in the height direction H than the first base portion 214A and the second base portion 214B.

[0084] According to the above-described structure, it is possible to suppress the welded portion 217 from coming into contact with other objects outside the secondary battery 10. Therefore, the handling of the secondary battery 10 becomes easier.

[0085] In this embodiment, the main body 210 further includes a liquid injection port 224 and a sealing member 225. The liquid injection port 224 is provided between the first terminal portion 216A and the second terminal portion 216B. The sealing member 225 seals the liquid injection port 224. The sealing member 225 is located closer to the bottom surface portion 211 than the first base portion 214A and the second base portion 214B in the height direction H.

[0086] According to the above configuration, the liquid injection port 224 can be easily provided without punching the plate-like member constituting the main body 210. In addition, the sealing member 225 can be prevented from contacting other objects outside the secondary battery 10. Therefore, the secondary battery 10 can be handled more easily.

[0087] (Implementation Method 2)

[0088] Next, the secondary battery according to the second embodiment of the present disclosure is described. In the secondary battery according to the second embodiment of the present disclosure, the configuration of the liquid injection port and the welding portion is different from that of the secondary battery 10 according to the first embodiment of the present disclosure. Therefore, the same configuration as that of the secondary battery 10 according to the first embodiment of the present disclosure will not be described repeatedly.

[0089] Figure 7 FIG. 2 is a top view of a secondary battery according to Embodiment 2. Figure 7 As shown, in the secondary battery 10x according to the second embodiment of the present disclosure, the injection port 224x is provided in at least one of the first base 214A and the second base 214B. As a result, the injection port 224x is located at a position more reliably away from the welding portion 217x, so that the sealing member 225 can be easily mounted on the injection port 224x without contacting the welding portion 217x compared to the first embodiment. In the present embodiment, a plurality of injection ports 224x are provided in the first base 214A and the second base 214B, respectively.

[0090] Fig. 8A This is a plan view showing a plate-like member prepared for molding a main body portion in the second embodiment. Figure 8B 1 is a plan view showing the state immediately after the plate-like member is bent in Embodiment 2. Fig. 8A and Figure 8B In the illustrated plate-shaped member 210Px, portions corresponding to the respective configurations of the main body 210 in the second embodiment are denoted by the same reference numerals as those indicating the respective configurations of the main body 210 .

[0091] like Fig. 8A and Figure 8B As shown, in Embodiment 2 of the present disclosure, a plurality of liquid injection ports 224x are formed in advance by punching out a plate-like member 210Px.

[0092] Although the embodiments of the present invention have been described, the embodiments disclosed this time should be considered to be illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the claims, and it is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A secondary battery, wherein: The secondary battery has: an electrode body; and a shell for accommodating the electrode body, The housing is configured such that a dimension in a width direction is longer than a dimension in a height direction and a dimension in a thickness direction perpendicular to the height direction, and the width direction is perpendicular to both the height direction and the thickness direction. The housing comprises: a main body having a cylindrical shape with a first opening and a second opening respectively provided at both ends in the width direction; a first sealing body for blocking the first opening; and a second sealing body for blocking the second opening. The main body has: A bottom surface portion, located at one side in the height direction; A first side surface portion rising from one end of the bottom surface portion in the thickness direction along the height direction; a second side surface portion rising from the other end of the bottom surface portion in the thickness direction along the height direction; a first top surface portion extending from an end portion of the first side surface portion on a side opposite to the bottom surface portion toward the second side surface portion; a second top surface portion extending from an end portion of the second side surface portion on a side opposite to the bottom surface portion toward the first side surface portion; and The welding portion connects the terminal edge of the first top surface portion and the terminal edge of the second top surface portion to each other.

2. The secondary battery according to claim 1, wherein The weld portion extends in only one direction along the width direction.

3. The secondary battery according to claim 1 or 2, wherein: The first top face portion comprises: a first base portion extending continuously from the first side face portion along the thickness direction; a first inner side face portion extending from the first base portion toward the bottom face portion; and a first terminal portion extending from the first inner side face portion along the thickness direction and having a terminal edge of the first top face portion, The second top face portion comprises: a second base portion extending continuously from the second side face portion along the thickness direction; a second inner side face portion extending from the second base portion toward the bottom face portion; and a second terminal portion extending from the second inner side face portion along the thickness direction and having a terminal edge of the second top face portion, The welding portion is located on the first terminal portion and the second terminal portion, and is located closer to the bottom surface portion than the first base portion and the second base portion in the height direction.

4. The secondary battery according to claim 3, wherein The main body further comprises: a liquid injection port disposed between the first terminal portion and the second terminal portion; and a sealing member for sealing the liquid injection port. The sealing member is located closer to the bottom surface portion than the first base portion and the second base portion in the height direction.

5. The secondary battery according to claim 3, wherein The main body further comprises: a liquid injection port, which is provided on at least one of the first base and the second base; and a sealing member to seal the liquid injection port.

Images