Battery and battery assembly method

Abstract

The present invention relates to the field of battery technology, and discloses a battery and a battery assembly method, wherein the battery includes a shell, a pole group, a negative pole cover plate and a first seal, wherein the bottom of the shell is open and a bent portion bent toward the inside thereof is provided at the bottom. In a battery of this structure, the negative pole cover plate is connected to the shell through a bent portion on the negative pole side, and the first seal is abutted and compressed by the bent portion, so that the first seal is sealed between the shell and the negative pole cover plate, thereby ensuring the sealing between the negative pole cover plate and the shell; the negative pole cover plate is welded to the pole group, and the outer peripheral wall of the negative pole cover plate abuts the inner peripheral wall of the bent portion, thereby realizing the conductive function of the negative pole cover plate and the shell. Compared with the existing structure, the battery of the present invention eliminates the negative pole connecting sheet and simplifies the structure; and the battery of this structure simplifies the assembly process of the battery during assembly, thereby effectively reducing the assembly cost of the battery and improving the production efficiency of the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery and a battery assembling method. Background Art

[0002] Cylindrical batteries include shells, electrode groups, upper plastic, lower plastic, poles, sealing rings, positive electrode connectors, negative electrode connectors, negative electrode covers, sealing covers, and sealing pins. During the assembly of cylindrical batteries, after the electrode group is placed in the shell, the electrode group and the negative electrode connector are laser welded, the negative electrode connector is laser welded to the shell, and then the negative electrode cover is laser welded to the shell. The entire assembly process of cylindrical batteries is complicated, with many welding steps, resulting in high assembly costs for cylindrical batteries and easily leading to poor performance of cylindrical batteries. Summary of the invention

[0003] In view of this, the present invention provides a battery to solve the problems of multiple welding steps, complex assembly process and high cost of existing batteries.

[0004] In the first aspect, the present invention provides a battery, characterized in that it includes a shell, a pole group, a negative electrode cover and a first seal, wherein the bottom of the shell is open and has a bent portion bent toward the inside thereof at the bottom; the pole group is arranged in the shell; a positioning groove is provided on the outer edge of the negative electrode cover; the negative electrode cover is arranged at the bottom opening of the shell, and the outer peripheral wall of the negative electrode cover abuts the inner peripheral wall of the bent portion; the negative electrode cover is welded to the pole group; the first seal is arranged in the positioning groove; the inner side of the bent portion abuts the first seal to seal the first seal between the bent portion and the negative electrode cover.

[0005] The battery of this structure connects the negative electrode cover plate and the shell through a bending portion on the negative electrode side, and abuts and compresses the first seal through the bending portion, so that the first seal is sealed between the shell and the negative electrode cover plate, ensuring the sealing between the negative electrode cover plate and the shell; the negative electrode cover plate is welded to the electrode group, and the outer peripheral wall of the negative electrode cover plate abuts the inner peripheral wall of the bending portion to achieve the conductive function of the negative electrode cover plate and the shell. Compared with the existing structure, the battery of the present invention eliminates the negative electrode connecting sheet and simplifies the structure; and when assembling the battery of this structure, compared with the existing structure, the steps of welding the electrode group and the negative electrode connecting sheet, welding the negative electrode connecting sheet and the shell, and welding the negative electrode cover plate and the shell are omitted, simplifying the assembly process of the battery, so as to effectively reduce the assembly cost of the battery, improve the production efficiency of the battery, and effectively ensure the performance of the battery after reducing the welding process, and reduce the product defect rate.

[0006] In an optional embodiment, the bending portion includes an outer portion, an inner portion and an arc portion, the arc portion connects the outer portion and the inner portion, and the inner portion abuts against the first sealing component.

[0007] The outer side, inner side and outer peripheral wall of the negative electrode cover are parallel to the side wall of the shell, so as to effectively press the first seal toward the outer peripheral wall and outer side of the negative electrode cover to ensure effective sealing between the negative electrode cover and the shell.

[0008] In an optional implementation, the height of the bending portion in the vertical direction is H, the width of the bending portion in the horizontal direction is W, 2.5 mm ≤ H ≤ 3.2 mm, 1.6 mm ≤ W ≤ 2.2 mm.

[0009] The height of the bending portion is moderate to avoid the bending portion height being too high to reduce the space utilization rate of the shell, and at the same time prevent the bending portion height from being too low to ensure the sealing effect between the shell and the negative electrode cover plate; the width of the bending portion is moderate to prevent the bending portion width from being too small to ensure the sealing, and at the same time avoid the bending portion width being too large to be difficult to process, and when the bending portion width is large, the size of the first seal needs to be increased accordingly, the weight of the first seal increases, and the cost increases. The width of the bending portion is moderate to avoid the need to increase the size of the first seal accordingly, so as to effectively control the weight and cost of the first seal.

[0010] In an optional embodiment, the inner side is parallel to the side wall of the shell, or the inner side is inclined at a preset angle toward the side wall of the shell; when the inner side is inclined with the side wall of the shell, the preset angle at which the inner side is inclined toward the side wall of the shell is a, 0°<a≤45°.

[0011] The inner side portion is parallel to the shell side wall or inclined toward the shell inner wall at a preset angle, so that the inner side portion can fully contact and squeeze the first seal, so as to fully compress the first seal and fully deform the first seal to ensure the sealing effect.

[0012] In an optional embodiment, it also includes a pole, an upper plastic, a second seal and a lower plastic. The upper plastic, the second seal and the lower plastic are integrated into one piece. The upper plastic and the lower plastic are respectively arranged on the outer wall surface and the inner wall surface of the top wall of the shell, and the second seal connects the upper plastic and the lower plastic; a mounting hole is provided on the top of the shell, the pole is arranged in the mounting hole, and the pole is electrically connected to the pole group.

[0013] The present invention integrates the sealing component and the insulating component to form an insulating seal, which reduces the number of parts and the assembly process of the battery, and greatly reduces the manufacturing cost of the battery. The pole is directly electrically connected to the pole group, and compared with the prior art, the positive electrode connecting piece is omitted, which further reduces the number of battery parts, eliminates the welding process of the positive electrode connecting piece and the pole group, and reduces the assembly process of the battery.

[0014] In an optional embodiment, an operating groove is provided on the top of the pole, the bottom of the pole contacts the pole group, and the pole below the operating groove is connected to the pole group by penetration welding.

[0015] Compared with the prior art which provides a positive electrode connecting piece and inserts a welding gun from the bottom of the shell into the center hole of the electrode group to weld the positive electrode connecting piece and the electrode group, this structure can directly penetrate and weld the electrode column and the electrode group from the outside conveniently and quickly, thereby improving the assembly efficiency of the battery.

[0016] In an optional embodiment, the area of ​​the electrode column and the electrode group welding region is S, S>135mm 2 ; and / or, the thickness of the pole below the operating slot is h, 0.8mm<h<1.2mm; and / or, there are multiple operating slots and the cross-section of the operating slot is triangular.

[0017] If the pole welding area is too small, its current carrying capacity will be affected. S>135mm 2 , to ensure the current carrying capacity of the pole. A too large pole welding area will affect the pole's own strength and its riveting strength. Preferably, S = 146mm 2 The pole welding area is moderate, which can prevent the pole slot area from being too large to affect its own strength and riveting strength. The thickness of the pole in the operation slot area is moderate to ensure the strength of the pole, and at the same time facilitate the welding of the pole and the pole group by laser penetration welding.

[0018] A plurality of operating slots are provided and the cross section of the operating slots is triangular to ensure the strength of the pole.

[0019] In an optional embodiment, the outer edge of the lower plastic extends downward to form an extension portion, the outer side wall of the extension portion abuts the side wall of the shell, and / or the inner side wall of the extension portion abuts the pole group to limit the pole group and ensure that the pole group is coaxial with the shell.

[0020] In an optional embodiment, a first recessed portion and a second recessed portion are formed on the negative electrode cover plate between the middle portion of the negative electrode cover plate and the positioning groove, and an explosion-proof notch is provided on the negative electrode cover plate at the first recessed portion. During the process of rolling and sealing the bending portion, the connecting surface between the positioning groove and the second recessed portion, and the connecting surface between the second recessed portion and the first recessed portion can play a buffering role, preventing the negative electrode cover plate at the first recessed portion from deforming, thereby ensuring the normal operation of the explosion-proof notch.

[0021] In a second aspect, the present invention further provides a battery assembly method for assembling any of the above batteries, comprising the following steps:

[0022] Placing the electrode group in the housing;

[0023] Placing the first sealing member in the positioning groove of the negative electrode cover plate, and placing the negative electrode cover plate in the bottom opening of the housing;

[0024] A bent portion is formed at the bottom of the rolled shell, and the inner side of the bent portion abuts against the first sealing member to seal and press the first sealing member between the negative electrode cover plate and the bent portion;

[0025] The negative electrode cover plate and the electrode group are welded together on the outer side of the negative electrode cover plate by penetration welding.

[0026] The battery assembly method of the present invention only needs to place the first seal into the positioning groove after the electrode group is put into the shell, and then place the negative electrode cover and the first seal into the bottom opening of the shell, and then roll the bottom of the shell to form a bending portion, and press the first seal through the bending portion to effectively ensure the sealing between the shell and the negative electrode cover, and the outer peripheral wall of the negative electrode cover contacts the shell to achieve the conductive function, and finally weld the negative electrode cover to the electrode group by penetration welding. Compared with the existing battery assembly method, two welding processes are reduced, the battery assembly steps are simplified, and the battery assembly efficiency is significantly improved; and the negative electrode cover and the pole are welded externally by penetration welding, which is convenient and quick.

[0027] In an optional embodiment, the battery includes a pole, an operation slot is provided on the top of the pole, and a mounting hole is provided on the top of the shell. Before placing the pole group in the shell, the following steps are also included:

[0028] Pass the pole through the mounting hole and fix the pole on the housing;

[0029] The pole is penetrated and welded to the pole group through the operating groove outside the pole.

[0030] The battery assembly method of the present invention penetrates and welds the pole to the pole group through the operation groove outside the pole. Compared with the existing battery including the positive electrode connecting piece, when assembling the battery, the positive electrode connecting piece and the pole group are first welded from the inside of the shell, and then the positive electrode connecting piece and the pole are welded, which can reduce the welding process. The pole and the pole group are penetrated and welded outside the shell to improve the welding convenience and improve the assembly efficiency of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 A schematic diagram of the three-dimensional structure of a battery according to an embodiment of the present invention;

[0033] Figure 2 A top view of a battery according to an embodiment of the present invention;

[0034] Figure 3 for Figure 2 AA cross-sectional view;

[0035] Figure 4An exploded diagram of a battery according to an embodiment of the present invention;

[0036] Figure 5 It is a schematic diagram of the cooperation between the negative electrode cover plate and the first sealing member in a battery according to an embodiment of the present invention;

[0037] Figure 6 A schematic diagram of a battery shell during the crimping process according to an embodiment of the present invention;

[0038] Figure 7 A schematic diagram of the three-dimensional structure of a battery pole according to an embodiment of the present invention;

[0039] Figure 8 A top view of a battery pole according to an embodiment of the present invention;

[0040] Fig. 9 for Figure 8 BB cross-sectional view.

[0041] Description of reference numerals:

[0042] 1. Shell; 101. Bending portion; 1011. Outer portion; 1012. Inner portion; 1013. Arc portion; 2. Pole group; 3. Negative electrode cover; 301. Positioning groove; 302. First recessed portion; 303. Second recessed portion; 304. Explosion-proof notch; 305. First rib portion; 306. Second rib portion; 307. Third rib portion; 308. Fourth rib portion; 309. Fifth rib portion; 310. Sixth rib portion; 4. First sealing member; 5. Pole; 501. Operating groove; 6. Insulating sealing member; 601. Upper plastic; 602. Second sealing member; 603. Lower plastic; 6031. Extension portion; 7. Sealing nail; 8. Sealing cover. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0044] Combine the following Figures 1 to 9 , describing an embodiment of the present invention.

[0045] According to an embodiment of the present invention, on the one hand, a battery is provided, which includes a shell 1, an electrode group 2, a negative electrode cover plate 3 and a first seal 4, wherein the bottom of the shell 1 is open and a bending portion 101 bent toward the inside thereof is provided at the bottom; the electrode group 2 is arranged in the shell 1; a positioning groove 301 is provided at the outer edge of the negative electrode cover plate 3; the negative electrode cover plate 3 is arranged at the bottom opening of the shell 1, and the outer peripheral wall of the negative electrode cover plate 3 abuts the inner peripheral wall of the bending portion 101; the negative electrode cover plate 3 is welded to the electrode group 2; the first seal 4 is arranged in the positioning groove 301; the inner side of the bending portion 101 abuts the first seal 4, so as to seal and press the first seal 4 between the bending portion 101 and the negative electrode cover plate 3.

[0046] The battery of this structure connects the negative electrode cover plate 3 and the shell 1 through the bending portion 101 on the negative electrode side, and the bending portion 101 abuts and compresses the first seal 4, so that the first seal 4 is sealed between the shell 1 and the negative electrode cover plate 3, ensuring the sealing between the negative electrode cover plate 3 and the shell 1; the negative electrode cover plate 3 is welded to the electrode group 2, and the outer peripheral wall of the negative electrode cover plate 3 abuts the inner peripheral wall of the bending portion 101, realizing the conductive function of the negative electrode cover plate 3 and the shell 1. Compared with the existing structure, the battery of the present invention eliminates the negative electrode connecting sheet and simplifies the structure; and when assembling the battery of this structure, compared with the existing structure, the steps of welding the electrode group 2 to the negative electrode connecting sheet, welding the negative electrode connecting sheet to the shell 1, and welding the negative electrode cover plate 3 to the shell 1 are omitted, simplifying the assembly process of the battery, so as to effectively reduce the assembly cost of the battery, improve the production efficiency of the battery, and effectively ensure the performance of the battery after reducing the welding process, and reduce the product defect rate.

[0047] Optionally, in one embodiment, the battery is a cylindrical battery.

[0048] like Figure 3 As shown, the area below the position where the top surfaces of the outer peripheral walls of the shell 1 and the negative electrode cover plate 3 are aligned serves as the bent portion 101 .

[0049] like Figure 3 As shown, the bending portion 101 includes an outer portion 1011, an inner portion 1012 and an arc portion 1013, the arc portion 1013 connects the outer portion 1011 and the inner portion 1012, and the inner portion 1012 abuts against the first sealing member 4. During the battery assembly process, in the initial state, the bottom of the shell 1 is in a vertical state, the first sealing member 4 is first installed in the positioning groove 301, and then the negative electrode cover plate 3 is installed in the shell 1, and the bottom of the shell 1 is rolled to form a bending portion 101.

[0050] In one embodiment, the inner side is parallel to the side wall of the shell, or the inner side is inclined toward the side wall of the shell at a preset angle; when the inner side is inclined with the side wall of the shell, the preset angle at which the inner side is inclined toward the side wall of the shell is a, 0°<a≤45°

[0051] The inner side portion is parallel to the shell side wall or inclined toward the shell inner wall at a preset angle, so that the inner side portion can fully contact and squeeze the first seal, so as to fully compress the first seal and fully deform the first seal to ensure the sealing effect.

[0052] See also Figure 3 , the height of the bending portion 101 in the vertical direction is H, and the width of the bending portion 101 in the horizontal direction is W, 2.5mm≤H≤3.2mm, the height of the bending portion 101 is moderate, avoiding the bending portion 101 from being too high to reduce the space utilization rate of the shell 1, and at the same time preventing the bending portion 101 from being too low to ensure the sealing effect between the shell 1 and the negative electrode cover plate 3; 1.6mm≤W≤2.2mm, the width of the bending portion 101 is moderate, preventing the bending portion 101 from being too small to ensure the sealing, and at the same time avoiding the bending portion 101 from being too large to be difficult to process, and when the width of the bending portion 101 is large, the size of the first seal 4 needs to be increased accordingly, the weight of the first seal 4 increases, and the cost increases. The width of the bending portion 101 is moderate to avoid the need to increase the size of the first seal 4 accordingly, so as to effectively control the weight and cost of the first seal 4.

[0053] Preferably, H=2.8 mm, W=1.9 mm, which can reduce the size and weight of the first seal 4 and the cost of the first seal 4 while ensuring the sealing performance and space utilization of the housing 1, and facilitate the rolling and sealing of the bending portion 101.

[0054] Optionally, the first sealing member 4 is a sealing ring.

[0055] like Figure 3 As shown, the battery also includes a pole 5, an upper plastic 601, a second seal 602 and a lower plastic 603. The upper plastic 601, the second seal 602 and the lower plastic 603 are integrated and arranged in one piece. The upper plastic 601 and the lower plastic 603 are arranged on the outer wall surface and the inner wall surface of the top wall of the shell 1 respectively. The second seal 602 connects the upper plastic 601 and the lower plastic 603. The top of the shell 1 is provided with a mounting hole, and the pole 5 is arranged in the mounting hole. The pole 5 is electrically connected to the pole group 2. In the prior art, the upper plastic 601, the second seal 602 and the lower plastic 603 are separately arranged, and the sealing component and the insulating component are separated. In the present invention, the sealing component and the insulating component are arranged in one piece to form an insulating seal 6, which reduces the number of parts and the assembly process of the battery, and greatly reduces the manufacturing cost of the battery. The pole 5 is directly electrically connected to the pole group 2, which eliminates the positive electrode connecting piece compared to the prior art, further reduces the number of battery parts, eliminates the welding process of the positive electrode connecting piece and the pole group 2, and shortens the battery assembly process.

[0056] like Figure 3As shown, the pole 5 is riveted and fixed on the top of the housing 1, the top outer edge of the upper plastic 601 is convex, and the top outer edge of the pole 5 abuts against the convex part of the upper plastic 601 to ensure insulation. The middle of the pole 5 abuts against the second sealing member 602, and the lower part of the pole 5 abuts against the bottom surface of the lower plastic 603.

[0057] like Figure 1 , Figure 3 , Figures 7 to 9 As shown, an operation groove 501 is provided at the top of the pole 5, the bottom of the pole 5 contacts the pole group 2, and the pole 5 below the operation groove 501 is connected to the pole group 2 by penetration welding. The operation groove 501 is provided at the top of the pole 5, so that the pole 5 and the pole group 2 can be welded by penetration welding outside the shell 1 through the operation groove 501. Compared with the prior art in which a positive electrode connecting piece is provided and a welding gun is inserted from the bottom of the shell 1 into the center hole of the pole group 2 to weld the positive electrode connecting piece and the pole group 2, the present structure can conveniently and quickly directly weld the pole 5 and the pole group 2 by penetration welding from the outside, so as to improve the assembly efficiency of the battery.

[0058] See also Figure 7 and Figure 8 The area of ​​the welding area between the pole 5 and the pole group 2 is S (i.e. the projection area of ​​the operation slot 501 on the pole group 2), S>135mm 2 If the welding area of ​​pole 5 is too small, its current carrying capacity will be affected. S>135mm 2 , to ensure the current carrying capacity of the pole 5. If the welding area of ​​the pole 5 is too large (i.e. the operation slot 501 is too large), it will affect the strength of the pole 5 itself and its riveting strength. Preferably, S = 146mm 2 The welding area of ​​the pole 5 is moderate, which can prevent the slot area of ​​the pole group 2 from being too large and affecting its own strength and riveting strength.

[0059] like Fig. 9 As shown, the thickness of the pole 5 below the operation groove 501 is h, 0.8mm<h<1.2mm, that is, the thickness of the pole 5 in the operation groove 501 area is moderate to ensure the strength of the pole 5 and facilitate welding the pole 5 and the pole group 2 by laser penetration welding.

[0060] There are multiple operating slots and the cross section of the operating slot is triangular to ensure the strength of the pole.

[0061] Alternatively, see Figure 7 and Figure 8 There are multiple operation grooves 501, and the multiple operation grooves 501 are arranged at equal intervals along the center line of the pole 5 to ensure uniform welding between the pole 5 and the pole group 2. For example, the cross section of the operation groove 501 is triangular, and there are four operation grooves 501.

[0062] Alternatively, if Figure 3As shown, the outer edge of the lower plastic 603 extends downward to form an extension portion 6031, the outer side wall of the extension portion 6031 abuts against the side wall of the housing 1, and the inner side wall of the extension portion 6031 abuts against the pole group 2, so as to limit the position of the pole group 2 and ensure that the pole group 2 is coaxial with the housing 1. Preferably, a limiting step surface is provided on the side of the extension portion 6031 facing the pole group 2, and the limiting step surface abuts against the top and side of the pole group 2. The limiting step surface can prevent the pole group 2 from moving up and down and moving sideways at the same time, and has a good positioning effect on the pole group 2.

[0063] In one embodiment, Figure 5 As shown, a first recessed portion 302 and a second recessed portion 303 are formed on the negative electrode cover plate 3 between the middle portion of the negative electrode cover plate 3 and the positioning groove 301, and an explosion-proof notch 304 is provided on the negative electrode cover plate 3 at the first recessed portion 302. The explosion-proof notch 304 is provided on the negative electrode cover plate 3 at the first recessed portion 302 inside the second recessed portion 303. During the process of rolling and sealing the bending portion 101, the connecting surface between the positioning groove 301 and the second recessed portion 303, and the connecting surface between the second recessed portion 303 and the first recessed portion 302 can play a buffering role, preventing the negative electrode cover plate 3 at the first recessed portion 302 from deforming, and ensuring the normal operation of the explosion-proof notch 304.

[0064] Specifically, if Figure 5 and Figure 6 As shown, the notch of the positioning groove 301 faces downward, the middle part of the negative electrode cover plate 3 is recessed upward, the first recessed portion 302 is recessed downward, and the second recessed portion 303 is recessed upward. From outside to inside along the radial direction of the negative electrode cover plate 3, the negative electrode cover plate 3 includes a first rib portion 305, a second rib portion 306, a third rib portion 307, a fourth rib portion 308, a fifth rib portion 309 and a sixth rib portion 310 which are arranged in sequence. The first rib portion 305 is arranged vertically, and the first rib portion 305 is the outer side wall of the negative electrode cover plate 3. The second rib portion 306 is arranged horizontally. The third rib portion 307 is arranged to be tilted downward from the second rib portion 306. The fourth rib portion 308 is arranged to be tilted upward from the bottom of the third rib portion 307 and then extends horizontally inward for a distance to connect with the fifth rib portion 309. The fifth rib portion 309 is arranged to be tilted downward and then connects with the horizontally arranged sixth rib portion 310. The explosion-proof notch 304 is arranged on the sixth rib portion 310. The first rib portion 305, the second rib portion 306 and the third rib portion 307 form a positioning groove 301. After the bending portion 101 is rolled and sealed, the end of the inner portion 1012 of the bending portion 101 presses the sealing ring against the inclined third rib portion 307 to ensure the sealing effect. The explosion-proof notch 304 is set on the sixth rib portion 310. During the rolling and sealing of the bending portion 101, the fourth rib portion 308 and the fifth rib portion 309 play a buffering role to prevent the sixth rib portion 310 from deforming, thereby preventing the explosion-proof notch 304 from being affected, and ensuring the normal use of the explosion-proof notch 304.

[0065] like Figure 3 , Figure 4 and Figure 6 As shown, the battery further includes a sealing nail 7 and a sealing cover plate 8. The sealing nail 7 is sealed and fixed at the nail hole in the middle of the negative electrode cover plate 3, and the sealing cover plate 8 is welded to the negative electrode cover plate 3 outside the sealing nail 7, and the sealing cover plate 8 is located in the concave area in the middle of the negative electrode cover plate 3.

[0066] According to an embodiment of the present invention, on the other hand, a battery assembly method is provided, which is used to assemble the above-mentioned battery, comprising the following steps:

[0067] Placing the pole group 2 in the housing 1;

[0068] Place the first sealing member 4 in the positioning groove 301 of the negative electrode cover plate 3, and place the negative electrode cover plate 3 in the bottom opening of the housing 1;

[0069] A bent portion 101 is formed at the bottom of the rolled shell 1, and the inner side of the bent portion 101 abuts against the first seal 4 to seal and press the first seal 4 between the negative electrode cover 3 and the bent portion 101;

[0070] The negative electrode cover plate 3 and the electrode group 2 are welded to the outer side of the negative electrode cover plate 3 by penetration welding.

[0071] The battery in the prior art includes a shell 1, an electrode group 2, a negative electrode connecting piece and a negative electrode cover plate 3. When the battery is assembled, after the electrode group 2 is put into the shell, it is necessary to first weld the negative electrode connecting piece to the electrode group 2, then weld the negative electrode connecting piece to the shell 1, and then weld the negative electrode cover plate 3 to the shell 1. There are many welding steps, the battery assembly process is complicated, and the production efficiency is low.

[0072] According to the battery assembly method of the present invention, after the pole group 2 is placed in the shell, it is only necessary to place the first seal 4 into the positioning groove 301, then place the negative electrode cover plate 3 and the first seal 4 into the bottom opening of the shell 1, and then roll the bottom of the shell 1 to form a bending portion 101, and press the first seal 4 through the bending portion 101 to effectively ensure the sealing between the shell 1 and the negative electrode cover plate 3, and the outer peripheral wall of the negative electrode cover plate 3 contacts the shell 1 to achieve the conductive function, and finally weld the negative electrode cover plate 3 to the pole group 2 by penetration welding. Compared with the existing battery assembly method, two welding processes are reduced, the battery assembly steps are simplified, and the battery assembly efficiency is significantly improved; and the negative electrode cover plate 3 and the pole 5 are welded externally by penetration welding, which is convenient and quick. Figure 6 It is a schematic diagram of the shell 1 during the sealing process.

[0073] Optionally, the negative electrode cover plate 3 and the electrode group 2 are welded by laser penetration welding.

[0074] The battery includes an upper plastic 601 , a lower plastic 603 and a second sealing member 602 , and the upper plastic 601 , the lower plastic 603 and the second sealing member 602 are integrally arranged to form an insulating sealing member 6 .

[0075] The battery also includes a pole 5, the top of the pole 5 is provided with an operating groove 501, and the top of the shell 1 is provided with a mounting hole. When assembling the pole 5, the insulating seal 6 is first placed on the shell 1 outside the mounting hole, the upper plastic 601 is located on the top surface of the top wall of the shell 1, and the lower plastic 603 abuts against the bottom surface of the top wall of the shell 1. Before placing the pole group 2 in the shell 1, the following steps are also included:

[0076] Pass the pole 5 through the mounting hole and fix the pole 5 on the housing 1;

[0077] The pole 5 is penetrated and welded to the pole group 2 through the operating groove 501 outside the pole 5 .

[0078] The assembly method of the battery of the present invention penetrates and welds the pole 5 to the pole group 2 through the operation groove 501 outside the pole 5. Compared with the existing battery including the positive electrode connecting piece, when assembling the battery, the positive electrode connecting piece and the pole group 2 are first welded from the inside of the shell 1, and then the positive electrode connecting piece and the pole 5 are welded, which can reduce the welding process. The pole 5 and the pole group 2 are penetrated and welded outside the shell 1 to improve the welding convenience and improve the assembly efficiency of the battery.

[0079] Optionally, the pole 5 and the pole group 2 are welded by laser penetration welding.

[0080] The battery further includes a sealing nail 7 and a sealing cover plate 8 .

[0081] The assembly method of the battery of the present invention is as follows:

[0082] Place the insulating seal 6 into the mounting hole of the housing 1, and rivet the pole 5 to the housing 1;

[0083] Pole group 2 enters the shell;

[0084] Place the first sealing member 4 into the positioning groove 301, and install the negative electrode cover plate 3 into the opening at the bottom of the housing 1;

[0085] A bending portion 101 is formed at the bottom of the rolled shell 1, and the inner side portion 1012 of the bending portion 101 abuts against the first sealing member 4 to seal and press the first sealing member 4 between the negative electrode cover plate 3 and the bending portion 101;

[0086] Welding the negative electrode cover plate 3 and the electrode group 2 by laser penetration welding;

[0087] injection;

[0088] Weld the sealing nail 7 to the nail hole in the middle of the negative electrode cover plate 3;

[0089] The sealing cover plate 8 is welded to the negative electrode cover plate 3 outside the sealing pin 7 .

[0090] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A battery, characterized in that: include: A shell, the bottom of the shell is open and the bottom is provided with a bent portion bent toward the inside thereof; A pole group, arranged in the shell; A negative electrode cover plate, with a positioning groove on the outer edge; the negative electrode cover plate is arranged at the bottom opening of the shell, and the outer peripheral wall of the negative electrode cover plate abuts against the inner peripheral wall of the bent portion; the negative electrode cover plate is welded to the electrode group; A first sealing member is disposed in the positioning groove; the inner side of the bent portion abuts against and compresses the first sealing member, so as to seal and press the first sealing member tightly between the bent portion and the negative electrode cover plate; The bending portion includes an outer portion, an inner portion and an arc portion, the arc portion connects the outer portion and the inner portion, and the inner portion abuts against the first sealing member; The height of the bending portion in the vertical direction is H, the width of the bending portion in the horizontal direction is W, 2.5mm≤H≤3.2mm, 1.6mm≤W≤2.2mm; The inner portion is parallel to the side wall of the shell, or the inner portion is inclined at a preset angle toward the side wall of the shell; when the inner portion is inclined with the side wall of the shell, the preset angle at which the inner portion is inclined toward the side wall of the shell is a, 0°<a≤45°.

2. The battery according to claim 1, characterized in that It also includes a pole, an upper plastic, a second seal and a lower plastic, wherein the upper plastic, the second seal and the lower plastic are integrated and arranged in one piece, the upper plastic and the lower plastic are arranged on the outer wall surface and the inner wall surface of the top wall of the shell, respectively, and the second seal connects the upper plastic and the lower plastic; A mounting hole is provided on the top of the shell, the pole is arranged in the mounting hole, and the pole is electrically connected to the pole group.

3. The battery according to claim 2, characterized in that An operating groove is provided on the top of the pole, and the bottom of the pole contacts the pole group. The pole below the operating groove is connected to the pole group by penetration welding.

4. The battery according to claim 3, characterized in that The area of ​​the welding region between the pole and the pole group is S, S>135mm²; And / or, the thickness of the pole below the operating slot is h, 0.6 mm < h < 1.2 mm; And / or, the operation groove is provided in plurality and the cross section of the operation groove is triangular.

5. The battery according to any one of claims 2 to 4, characterized in that The outer edge of the lower plastic extends downward to form an extension portion, the outer side wall of the extension portion abuts against the side wall of the shell, and / or the inner side wall of the extension portion abuts against the pole group.

6. A battery assembly method, characterized in that: For assembling the battery according to any one of claims 1 to 5, comprising the following steps: placing the pole group in the housing; Placing the first sealing member in the positioning groove of the negative electrode cover plate, and placing the negative electrode cover plate in the bottom opening of the housing; The bottom of the shell is rolled to form the bent portion, and the inner side of the bent portion is made to abut against the first sealing member to seal and press the first sealing member between the negative electrode cover plate and the bent portion; The negative electrode cover plate and the electrode group are welded on the outer side of the negative electrode cover plate by penetration welding.

7. The battery assembly method according to claim 6, characterized in that: The battery comprises a pole, an operation slot is provided on the top of the pole, a mounting hole is provided on the top of the shell, and the following steps are also included before the pole group is placed in the shell: Pass the pole through the mounting hole and fix the pole on the housing; The pole is penetrated and welded to the pole group through the operation groove outside the pole.

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