Secondary battery

Abstract

The invention provides a secondary battery. In the secondary battery, a first end surface portion extends from one end of a first side surface portion in a width direction toward a second side surface portion. The second end surface portion extends from one end of the second side surface portion in the width direction toward the first side surface portion. The end face welding portion connects the end edge of the first end face portion and the end edge of the second end face portion to each other. The tip edge of the first end surface portion is positioned closer to the center side of the housing than a connection portion between the first end surface portion and the first side surface portion in the width direction. The tip edge of the second end surface portion is positioned closer to the center side of the housing than a connection portion between the second end surface portion and the second side surface portion in the width direction.

Description

Technical Field

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

[0002] Japanese Patent Publication No. 2013-125737 discloses a secondary battery having a housing for housing an electrode body. The main body of the housing is formed by bending a metal plate and welding the edges of the bent metal plate to each other. The metal plate has a bottom portion, a pair of side portions, and four half end portions. The edges of the half end portions facing each other are butted against each other and joined by welding. Summary of the invention

[0003] In order to increase the energy density of secondary batteries, it is required to enlarge the shell of the secondary battery. In the secondary battery disclosed in Japanese Patent Publication No. 2013-125737, it is studied to make the shell longer in the direction in which the end faces are arranged with each other (width direction). However, if the shell is made longer in the width direction, the welding part on the end face protrudes in the width direction, and sometimes the handling of the secondary battery becomes difficult.

[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 capable of suppressing protrusion of a weld portion on an end surface.

[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 provided with an opening and a sealing body blocking the opening. The main body comprises a bottom face portion, a first side face portion, a second side face portion, a first end face portion, a second end face portion and an end face 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 end face portion extends from one end in the width direction of the first side face portion toward the second side face portion. The second end face portion extends from one end in the width direction of the second side face portion toward the first side face portion. The end face welding portion connects the terminal edge of the first end face portion and the terminal edge of the second end face portion to each other. The terminal edge of the first end face portion is located in the width direction at a position closer to the center side of the shell than the connection portion between the first end face portion and the first side face portion. The terminal edge of the second end surface portion is located closer to the center of the housing than a connection portion between the second end surface portion and the second side surface portion in the width direction.

[0006] According to the above configuration, since the respective terminal edges of the first end surface portion and the second end surface portion are located at the above-mentioned positions, it is possible to suppress the end surface welded portion from protruding in the width direction.

[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 a secondary battery according to one embodiment.

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

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

[0011] Figure 4 This is a diagram of a secondary battery according to an embodiment viewed from an end surface side.

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

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

[0014] One embodiment 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.

[0015] Figure 1 This is a perspective view of a secondary battery according to one embodiment. Figure 2 This is an exploded perspective view of a secondary battery according to one embodiment. Figure 3 It is along Figure 1 A cross-sectional view along line III-III is shown. Figure 4 This is a diagram of a secondary battery according to an embodiment viewed from an end surface side.

[0016] like Figures 1 to 4 As shown, a secondary battery 10 according to one embodiment of the present disclosure 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.

[0017] 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 perpendicular to the height direction H. The width direction W is a direction perpendicular to both the height direction H and the thickness direction T. In addition, the thickness direction T is perpendicular to the positive electrode 110 and the negative electrode 120 (see Figure 6) The direction of arrangement configuration is parallel to the direction.

[0018] The case 200 accommodates the electrode body 100 and an electrolyte (not shown). The case 200 has a main body portion 210 provided with an opening OP and a sealing body 510 that blocks the opening OP.

[0019] The opening OP of the main body 210 is provided on one side in the width direction W. The main body 210 is made of metal such as aluminum.

[0020] The main body 210 includes a bottom surface portion 211 , a top surface portion 212 , a first side surface portion 215A, a second side surface portion 215B, a first end surface portion 216A, a second end surface portion 216B, an end surface welding portion 220 , a liquid injection port 224 , and a sealing member 225 .

[0021] The bottom surface portion 211 is located on one side in the height direction H. The bottom surface portion 211 has a substantially rectangular outer shape when viewed from the height direction H.

[0022] The top surface portion 212 is located on the other side in the height direction H. The top surface portion 212 has a substantially rectangular outer shape when viewed in the height direction H.

[0023] In the present embodiment, the top surface portion 212 includes a first top surface portion 213A, a second top surface portion 213B, and a top surface welding portion 214 .

[0024] The first top face portion 213A and the second top face portion 213B are opposite to each other in the thickness direction T. The first top face portion 213A and the second top face portion 213B are joined by mutual welding. By this welding, the top face welding portion 214 is formed. The top face welding portion 214 extends in one direction along the width direction W.

[0025] In addition, the top surface portion 212 may be a single plate-shaped member as a whole. In the case where the main body portion 210 has an opening at a position opposite to the bottom surface portion 211, the top surface portion 212 may be a sealing member that seals the opening.

[0026] The first side surface portion 215A 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 215B 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 215A and the second side surface portion 215B have a rectangular shape. The first side surface portion 215A and the second side surface portion 215B may be inclined with respect to the height direction H. The first side surface portion 215A and the second side surface portion 215B may extend in a manner of approaching each other as they move away from the bottom surface portion 211.

[0027] The first side surface portion 215A is connected to the top surface portion 212, specifically, connected to the edge of the first top surface portion 213A. The second side surface portion 215B is connected to the top surface portion 212, specifically, connected to the edge of the second top surface portion 213B.

[0028] The first end surface 216A extends from one end of the first side surface 215A in the width direction W toward the second side surface 215B. The terminal edge of the first end surface 216A is located in the width direction W closer to the center of the housing 200 than the connection between the first end surface 216A and the first side surface 215A.

[0029] The first end surface portion 216A has a first base portion 217A, a first inner side portion 218A, and a first terminal portion 219A. The first base portion 217A extends continuously from the first side portion 215A along the thickness direction T. The first inner side portion 218A extends from the first base portion 217A toward the center side of the housing 200. The first inner side portion 218A is inclined relative to the width direction W. The first terminal portion 219A extends from the first inner side portion 218A along the thickness direction T and has a terminal edge of the first end surface portion 216A.

[0030] The second end surface 216B extends from one end of the second side surface 215B in the width direction W toward the first side surface 215A. The terminal edge of the second end surface 216B is located in the width direction W closer to the center of the housing 200 than the connection between the second end surface 216B and the second side surface 215B.

[0031] The second end surface portion 216B has a second base portion 217B, a second inner side portion 218B, and a second terminal portion 219B. The second base portion 217B extends continuously from the second side portion 215B along the thickness direction T. The second inner side portion 218B extends from the second base portion 217B toward the central side of the housing 200. The second inner side portion 218B is inclined relative to the width direction W. The second terminal portion 219B extends from the second inner side portion 218B along the thickness direction T and has a terminal edge of the second end surface portion 216B.

[0032] The end face welding part 220 connects the end edge of the first end face part 216A and the end edge of the second end face part 216B to each other. That is, the end face welding part 220 is formed by connecting the end edge of the first end face part 216A and the end edge of the second end face part 216B by welding. The welding method is not particularly limited, and it can be laser welding, for example. The end face welding part 220 includes a weld bead formed by the above welding. The weld bead protrudes from the first end face part 216A and the second end face part 216B toward the outside of the housing 200.

[0033] The end surface welded portion 220 extends in only one direction along the height direction H. The end surface welded portion 220 is located on the first terminal portion 219A and the second terminal portion 219B. The end surface welded portion 220 is located closer to the center of the housing 200 in the width direction W than the first base portion 217A and the second base portion 217B.

[0034] In addition, in the present embodiment, the main body 210 has a plurality of end surface welds 220 as the above-mentioned end surface welds 220. The plurality of end surface welds 220 are separated from each other. The plurality of end surface welds 220 are arranged in the height direction H. In addition, the end surface welds 220 may also be provided to be connected to the top surface weld 214.

[0035] In this embodiment, one edge of 216A and 216B in the height direction H is also welded to the bottom surface portion 211. The other edge of the first end surface portion 216A and the second end surface portion 216B in the height direction is also welded to the top surface portion 212.

[0036] The liquid injection port 224 is a through hole for injecting electrolyte into the case 200 during the manufacturing process of the secondary battery 10. The sealing member 225 seals the liquid injection port 224. The sealing member 225 is provided to seal the liquid injection port 224 after the electrolyte is injected into the case 200.

[0037] The injection port 224 is provided between the first terminal portion 219A and the second terminal portion 219B. The sealing member 225 is located closer to the center side of the housing 200 than the first base portion 217A and the second base portion 217B in the width direction W. The hole shape of the injection port 224 is not particularly limited, and is, for example, circular. The main body 210 may also have a plurality of injection ports 224 as the above-mentioned injection port 224.

[0038] 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 .

[0039] 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.

[0040] Then, if Figure 5A and Figure 5B As shown, by bending the plate-like member 210P at multiple locations, the bottom surface portion 211, the first top surface portion 213A, the second top surface portion 213B, the first side surface portion 215A, the second side surface portion 215B, the first end surface portion 216A and the second end surface portion 216B are formed. Therefore, the main body portion 210 can be easily formed into various sizes. In addition, the above-mentioned surfaces can also be formed by roll-forming the plate-like member 210P. And, by avoiding the notch corresponding to the liquid injection port 224, the end edges of the plate-like member 210P formed in this way are welded to each other, thereby forming the top surface welding portion 214 and the end surface welding portion 220, etc. (refer to Figure 4 ), the main body 210 is formed. The opening OP of the main body 210 is formed by the end edges of the bottom surface 211, the top surface 212, the first side surface 215A and the second side surface 215B.

[0041] like Figures 1 to 3 As shown, the sealing body 510 blocks the opening OP. The sealing body 510 has a flat plate shape. The sealing body 510 is made of metal such as aluminum. A negative electrode component 520 and a positive electrode component 620 are provided on the sealing body 510. The sealing body 510 is fixed to the opening OP by, for example, laser welding. A pressure relief valve 515 is provided on the sealing body 510. The pressure relief 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 relief valve 515, the gas in the shell 200 is discharged to the outside of the shell 200, so that the internal pressure in the shell 200 is reduced.

[0042] The negative electrode member 520 is provided on the outer surface of the 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 .

[0043] 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 sealing body 510. The insulating plate 522 insulates the 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.

[0044] The positive electrode member 620 is provided on the outer surface of the sealing body 510 . 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 sealing body 510 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 sealing body 510 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. Through holes for inserting the positive electrode connecting pin 633 described later are 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 sealing body 510 to electrically insulate the positive electrode member 620 from the sealing body 510. In this case, an insulating plate may be disposed instead of the terminal block 622 or between the terminal block 622 and the sealing body 510.

[0048] The secondary battery 10 further includes a negative electrode connecting member 530 , a positive electrode connecting member 630 , a first insulating member 540 , a second insulating member 550 , and insulators 560 , 660 .

[0049] The negative electrode connecting member 530 connects the negative electrode current collecting portion 120N to the negative electrode terminal plate 521. The negative electrode current collecting portion 120N 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 negative electrode current collector 531, a negative electrode side second negative electrode current collector 532, and a negative electrode connecting pin 533.

[0050] The first negative electrode current collector 531 on the negative electrode side is formed of a thin plate-shaped conductive member and is connected to the negative electrode current collecting portion 120N by laser welding, ultrasonic welding or the like.

[0051] The second negative electrode collector 532 on the negative electrode side is composed of a thin plate-shaped conductive member. The second negative electrode collector 532 on the negative electrode side is connected to the first negative electrode collector 531 on the negative electrode side by laser welding or ultrasonic welding. The second negative electrode 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 negative electrode collector 532 to 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 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 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 positive electrode current collector 631, a positive electrode side second positive electrode current collector 632, and a positive electrode connecting pin 633.

[0054] The first positive electrode current collector 631 on the positive electrode side 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.

[0055] The second positive electrode collector 632 on the positive electrode side is composed of a thin plate-shaped conductive member. The second positive electrode collector 632 on the positive electrode side is connected to the first positive electrode collector 631 on the positive electrode side by laser welding or ultrasonic welding. The second positive electrode 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.

[0056] The positive electrode connecting pin 633 connects the positive electrode side second positive electrode collector 632 to 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 sealing body 510, the terminal block 622 and the positive electrode terminal plate 621, and is riveted to the positive electrode terminal plate 621.

[0057] The first insulating member 540 has a substantially plate-like shape and is disposed in contact with the inner surface of the sealing body 510. The first insulating member 540 is provided with a through hole 542 through which the negative electrode connecting pin 533 is inserted and a through hole 642 through which the positive electrode connecting pin 633 is inserted.

[0058] The second insulating member 550 is disposed between the first insulating member 540 and the electrode body 100. The second insulating member 550 is provided with a slit 552 through which the negative electrode current collecting portion 120N is inserted, and a slit 652 through which the positive electrode current collecting portion 110P is inserted.

[0059] The first insulating member 540 and the second insulating member 550 are assembled so as to form a storage space therebetween. The negative electrode collector 120N inserted through the slit 552, the first negative electrode collector 531 on the negative electrode side, the second negative electrode collector 532 on the negative electrode side, the positive electrode collector 110P inserted through the slit 652, the first positive electrode collector 631 on the positive electrode side, and the second positive electrode collector 632 on the positive electrode side are arranged in the storage space.

[0060] 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 sealing member 510).

[0061] 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 sealing member 510).

[0062] The negative electrode member 520 , the positive electrode member 620 , the sealing body 510 , the negative electrode connecting member 530 , the positive electrode connecting member 630 , the first insulating member 540 , the second insulating member 550 , and the insulators 560 and 660 are assembled to form the cap assembly 50 .

[0063] The cap assembly 50 is fixed to the main body 210 by attaching the sealing body 510 to the opening OP while the negative electrode collector 120N and the negative electrode connecting member 530 are fixed by welding or the like, and the positive electrode collector 110P and the positive electrode connecting member 630 are fixed by welding or the like.

[0064] It should be noted that the sealing body 510 may also be provided with a second injection port 572 and a second sealing member 574. The second injection port 572 is the same as the injection port 224, and is a through hole for injecting electrolyte into the housing 200 during the manufacturing process of the secondary battery 10. The second sealing member 574 seals the second injection port 572. The second sealing member 574 is provided to seal the second injection port 572 after injecting electrolyte into the housing 200.

[0065] 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.

[0066] 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 .

[0067] 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.

[0068] 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 one side in the width direction W similarly to the negative electrode tab 122n.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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).

[0073] 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 .

[0074] 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.

[0075] As described above, in the secondary battery 10 of one embodiment of the present disclosure, the end face welding portion 220 connects the terminal edge of the first end face portion 216A and the terminal edge of the second end face portion 216B to each other. The terminal edge of the first end face portion 216A is located closer to the center of the housing 200 than the connection portion between the first end face portion 216A and the first side face portion 215A in the width direction W. The terminal edge of the second end face portion 216B is located closer to the center of the housing 200 than the connection portion between the second end face portion 216B and the second side face portion 215B in the width direction W.

[0076] According to the above configuration, since the respective end edges of the first end surface portion 216A and the second end surface portion 216B are located at the above-mentioned positions, protrusion of the end surface weld portion 220 in the width direction W can be suppressed, particularly when the end surface weld portion 220 includes a weld bead.

[0077] Furthermore, the end surface welded portion 220 extends only in one direction along the height direction H. Thus, the welded length of the end surface welded portion 220 can be shortened. Furthermore, the weld strain of the housing 200 can be suppressed.

[0078] Furthermore, the first end surface portion 216A includes a first base portion 217A, a first inner side portion 218A, and a first terminal portion 219A. The first base portion 217A extends continuously from the first side portion 215A along the thickness direction T. The first inner side portion 218A extends from the first base portion 217A toward the central side of the housing 200. The first terminal portion 219A extends from the first inner side portion 218A along the thickness direction T and has a terminal edge of the first end surface portion 216A. The second end surface portion 216B includes a second base portion 217B, a second inner side portion 218B, and a second terminal portion 219B. The second base portion 217B extends continuously from the second side portion 215B along the thickness direction T. The second inner side portion 218B extends from the second base portion 217B toward the central side of the housing 200. The second terminal portion 219B extends from the second inner side portion 218B along the thickness direction T and has a terminal edge of the second end surface portion 216B. The end surface welded portion 220 is located on the first terminal portion 219A and the second terminal portion 219B. The end surface welded portion 220 is located closer to the center of the housing 200 in the width direction W than the first base portion 217A and the second base portion 217B.

[0079] According to the above structure, the first base portion 217A and the second base portion 217B extend along the thickness direction T, so the overall area of ​​the end surface of the main body portion 210 can be reduced. In addition, the first terminal portion 219A and the second terminal portion 219B also extend along the thickness direction T, so it is easy to butt them together to form the end surface welded portion 220. Moreover, the end surface welded portion 220 is located on the first terminal portion 219A and the second terminal portion 219B, thereby further suppressing the end surface welded portion 220 from protruding in the width direction W.

[0080] 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 219A and the second terminal portion 219B. The sealing member 225 seals the liquid injection port 224. The sealing member 225 is located closer to the center of the housing 200 in the width direction W than the first base portion 217A and the second base portion 217B.

[0081] According to the above configuration, the liquid injection port 224 can be easily provided without punching the plate-shaped member constituting the main body 210. In addition, the sealing member 225 can be prevented from contacting other objects on the secondary battery 10 side. Therefore, the secondary battery 10 can be handled more easily.

[0082] 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 an opening; and a sealing body for blocking the opening. The main body has: A bottom 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 end surface portion extending from one end of the first side surface portion in the width direction toward the second side surface portion; a second end surface portion extending from one end of the second side surface portion in the width direction toward the first side surface portion; and an end surface welding portion, connecting the terminal edge of the first end surface portion and the terminal edge of the second end surface portion to each other, The terminal edge of the first end surface portion is located closer to the center of the housing than a connection portion between the first end surface portion and the first side surface portion in the width direction. The terminal edge of the second end surface portion is located closer to the center of the housing than a connection portion between the second end surface portion and the second side surface portion in the width direction.

2. The secondary battery according to claim 1, wherein The end surface welding portion extends in only one direction along the height direction.

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

Images