Battery assembly method and battery

Abstract

The application belongs to the technical field of batteries, and discloses a battery assembling method and a battery. In the battery assembling method, on one hand, before the pole group enters the shell, an insulating film is wrapped on the surface of the pole group without the pole lug, and a cover plate module or a fixed end plate which is hot-melted with the insulating film is arranged on the side of the pole group with the pole lug, so that six surface protection is formed on the pole group, and the pole group is prevented from being damaged when entering the shell, and the product quality is improved. On the other hand, when assembling, the welding process of the open outer shell body is located before the welding process of the pole lug and the connecting piece, so that the pole lug and the connecting piece which have been welded are prevented from being affected by the vibration and high temperature in the welding process, the welding quality between the pole lug and the connecting piece is improved, and the difficulty of the welding operation of the pole lug and the connecting piece is reduced due to the fixed state between the cover plate module and the outer shell body.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a battery assembling method and a battery. BACKGROUND

[0002] The single-sided tab of the square shell battery is the core component of the construction, and the traditional square shell battery assembling process usually first assembles the pole group into the battery shell, then bends the positive and negative tabs on the same side of the pole group multiple times to form an approximate S shape, then assembles the cover plate assembly connected with the pole into the open end of the battery shell, and welds the tabs with the corresponding polarity and the pole, after the welding of the tabs and the pole is completed, the aluminum plate in the battery shell and the cover plate assembly are welded, the battery shell is closed, and the assembly of the square shell battery is completed.

[0003] However, the square shell battery assembled by the method has the following problems: on the one hand, since the surface of the pole group on one side is provided with tabs, in order to avoid interference with the tabs, an insulating film is usually wrapped on the surface of the pole group without tabs, so that when the pole group is assembled into the shell, the surface of the pole group provided with tabs is easily damaged due to the lack of protection; on the other hand, not only the welding of the tabs and the pole needs to be completed first, but also the vibration, high temperature and other adverse factors in the welding process of the aluminum plate and the battery shell will affect the welded tabs and the pole, thereby reducing the welding quality between the pole and the tabs and affecting the conductivity efficiency, and the cover plate assembly and the battery shell are in a relatively free state when the tabs and the pole are welded, which makes the operation difficult. SUMMARY

[0004] The present application aims to provide a battery assembling method and a battery with low operation difficulty, high welding quality and good protection.

[0005] To achieve this goal, the present application adopts the following technical solutions:

[0006] On the one hand, a battery assembling method is provided, and the battery assembled by the battery assembling method includes a pole group with tabs on the same side, a cover plate module, a shell body, a closing module and at most one fixed end plate.

[0007] The battery assembling method comprises the following steps:

[0008] S1, wrapping an insulating film on the outside of the surface of the pole group without tabs, and arranging the cover plate module or the fixed end plate hot-melted with the insulating film on the side of the pole group provided with the tabs, if the fixed end plate is hot-melted with the pole group, step S2A is performed, and if the cover plate module is hot-melted with the pole group, step S2B is performed;

[0009] S2A, a avoiding through slot for the tab to pass through is formed on the fixed end plate, the fixed end plate is arranged on the side of the pole group where the tab is arranged, and the fixed end plate is hot-melted with the insulation film; after the fixed end plate is hot-melted with the insulation film, step S2A is completed, and then step S3A is performed;

[0010] S3A, the shell body is a single-side open structure with a cavity, the pole group with the fixed end plate hot-melted is arranged in the cavity of the shell body, the cover plate module is arranged at the opening of the shell body, the cover plate module comprises a cover plate body, a pole column and a connecting piece, the cover plate body is provided with a connecting window in communication with the cavity of the shell body, one end of the connecting piece is fixed on the cover plate body by the pole column, the other end of the connecting piece extends to below the connecting window, the avoiding through slot for the tab to pass through is formed on the fixed end plate, and the tab passing through the avoiding through slot is bent to be overlapped on the surface of the connecting piece exposed below the connecting window; after step S3A is completed, step S4 is performed.

[0011] S2B, the cover plate module further comprises an insulation piece, the insulation piece is provided with a penetrating structure in communication with the connecting window, the cover plate module is arranged on the side of the pole group where the tab is arranged, and the tab is bent to be overlapped on the surface of the connecting piece exposed below the connecting window; after step S2B is completed, step S4 is performed.

[0012] S4, the cover plate body and the shell body are welded to seal the shell body.

[0013] S5, the tab exposed below the connecting window and the connecting piece are welded.

[0014] S6, the sealing module comprises a sealing plate and an insulation plate, the insulation plate is arranged on the side of the sealing plate facing the tab, the sealing plate is arranged at the connecting window of the cover plate body, and the sealing plate and the cover plate body are welded.

[0015] Optionally, in step S1, the following step is further included:

[0016] S11, the battery further comprises a bottom supporting plate, and the bottom supporting plate is pre-hot-melted at a designated position of the insulation film.

[0017] S12, the insulation film is wrapped on the surface of the pole group where the tab is not arranged, and the bottom supporting plate covers the surface of the pole group away from the tab.

[0018] Optionally, in step S6, the following step is further included:

[0019] S61, a mounting boss is arranged on the side of the cover plate body away from the pole group, a mounting through hole in communication with the connecting window and arranged in a stepped distribution is arranged on the mounting boss, and a limiting step is formed between the mounting through hole and the connecting window, the closure plate comprises a closure part and a plug-in part, the insulating plate is arranged on the side of the plug-in part away from the closure part, the plug-in part of the closure plate is inserted into the connecting window, the closure part of the closure plate is inserted into the mounting through hole, and the closure part is in abutment with the limiting step;

[0020] S62, the closure part is welded with the cover plate body.

[0021] Optionally, the width dimension of the limiting step and the closure part in the first direction is W, when the closure part and the cover plate body are butt joint welded, the width dimension W satisfies 0.5mm≤W≤20mm.

[0022] Optionally, when the closure part and the cover plate body are penetration welded, the width dimension W satisfies 1mm≤W≤20mm.

[0023] On the other hand, a battery is provided, which is assembled by the battery assembling method as any one of the above.

[0024] Optionally, the side of the insulating plate away from the closure plate is provided with a plug-in groove, the side of the insulating part towards the cover plate body is provided with a plug-in protrusion, the plug-in protrusion is continuously arranged around the circumferential edge of the through structure, and the plug-in protrusion is inserted into the plug-in groove.

[0025] Optionally, the fixing end plate is further provided with a shaping extension edge, the shaping extension edge is arranged on the wall surface of the avoiding through groove, and the included angle between the extending direction of the shaping extension edge and the wall surface is an acute angle.

[0026] Optionally, the connecting sheet comprises a first connecting part and a second connecting part, the first connecting part is connected with the pole column, the second connecting part is connected with the pole lug, a through slot is arranged on the second connecting part, and the pole lug is connected with the second connecting part by penetrating through the through slot.

[0027] Optionally, the cross section of the connecting sheet is Z-shaped or I-shaped.

[0028] The beneficial effects of the present application are as follows:

[0029] This invention provides a battery assembly method. Firstly, before the electrode assembly is inserted into the casing, an insulating film is wrapped around the surface of the electrode assembly without tabs. A cover module or fixed end plate, heat-fused to the insulating film, is then installed on the side of the electrode assembly with tabs, thus providing six-sided protection for the electrode assembly. This prevents damage to the electrode assembly during casing insertion and improves product quality. Secondly, during assembly, the welding process of the closed casing body is placed before the welding process of the tabs and connecting pieces. This avoids the impact of vibration, high temperature, and other adverse factors during the welding process on the already welded tabs and connecting pieces, improving the welding quality between them. Furthermore, since the cover module is fixed to the casing body, the difficulty of welding the tabs and connecting pieces is reduced.

[0030] The present invention also provides a battery that, by applying the above-described battery assembly method and improving welding quality, ensures high conductivity, thereby improving power supply capacity and product quality. Attached Figure Description

[0031] Figure 1 This is a flowchart of the battery assembly method provided by the present invention;

[0032] Figure 2 This is a structural exploded view of the battery provided by the present invention;

[0033] Figure 3 This is a partial cross-sectional view of the battery cover module and the sealing module after assembly provided by the present invention;

[0034] Figure 4 This is a schematic diagram of the structure of the cover plate body in the cover plate module provided by the present invention;

[0035] Figure 5 yes Figure 4 Enlarged view of the structure of section A;

[0036] Figure 6 This is a schematic diagram of the integrated pole post and connecting piece provided by the present invention;

[0037] Figure 7 This is a schematic diagram of the structure of the insulating component in the cover plate module provided by the present invention;

[0038] Figure 8 This is a cross-sectional view of the structure of the enclosed module in the battery provided by the present invention;

[0039] Figure 9 This is a schematic diagram of the fixed end plate in the battery provided by the present invention.

[0040] In the picture:

[0041] 100, Electrode Group; 200, Electrode Sheet;

[0042] 1. Outer shell;

[0043] 2. Cover plate module; 21. Cover plate body; 211. Connecting window; 212. Mounting boss; 213. Mounting through hole; 214. Limiting step; 22. Pole post; 23. Connecting piece; 231. First connecting part; 232. Second connecting part; 233. Through groove; 24. Insulating component; 241. Through structure; 242. Insertion protrusion;

[0044] 3. Enclosed module; 31. Enclosed plate; 311. Enclosed part; 312. Insertion part; 32. Insulating plate; 321. Insertion groove;

[0045] 4. Fixed end plate; 41. Clearance slot; 42. Shaping edge;

[0046] 5. Insulating film;

[0047] 6. Base plate. Detailed Implementation

[0048] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0049] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0050] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0051] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0052] In the assembly of traditional square-shell batteries, on the one hand, the welding of the tabs and terminals takes place before the welding of the aluminum plate to the battery casing. This not only makes the already welded tabs and terminals susceptible to the high temperature and vibration during the welding of the aluminum plate to the battery casing, but also makes the welding of the tabs and terminals more difficult and unwieldy because the aluminum plate and the battery casing are in a relatively free state during the welding process. On the other hand, the surface of the electrode assembly with tabs lacks protection before being inserted into the casing, making it prone to damage during insertion and affecting product quality.

[0053] Therefore, in order to reduce the difficulty of welding operations and improve welding quality, this embodiment provides a battery assembly method. The battery assembled by the battery assembly method includes an electrode group 100 with a tab 200 on the same side, a cover module 2, a housing body 1, a sealing module 3, and at most one fixed end plate 4.

[0054] like Figures 1 to 9 As shown, the battery assembly method includes the following steps:

[0055] S1. Cover the outer surface of the electrode group 100 without the electrode tab 200 with an insulating film 5, and set a cover plate module 2 or a fixed end plate 4 that is heat-fused to the insulating film 5 on the side of the electrode group 100 with the electrode tab 200. If the fixed end plate 4 is heat-fused to the electrode group 100, then execute step S2A; if the cover plate module 2 is heat-fused to the electrode group 100, then execute step S2B.

[0056] S2A: A clearance groove 41 for the electrode tab 200 to pass through is provided on the fixed end plate 4. The fixed end plate 4 is placed on the side of the electrode group 100 where the electrode tab 200 is provided, and the fixed end plate 4 is heat-fused with the insulating film 5. After the fixed end plate 4 and the insulating film 5 are heat-fused, step S2A is completed, and step S3A is executed.

[0057] S3A: The outer shell body 1 has a single-sided open structure with a cavity. The electrode assembly 100 with the fixed end plate 4 hot-melted is installed into the cavity inside the outer shell body 1. The cover plate module 2 is placed at the open part of the outer shell body 1. The cover plate module 2 includes a cover plate body 21, an electrode post 22 and a connecting piece 23. The cover plate body 21 has a connection window 211 that communicates with the cavity of the outer shell body 1. One end of the connecting piece 23 is fixed to the cover plate body 21 by the electrode post 22. The other end of the connecting piece 23 extends to the bottom of the connection window 211. The fixed end plate 4 has a clearance groove 41 for the electrode tab 200 to pass through. The electrode tab 200 that passes through the clearance groove 41 is bent so that the electrode tab 200 overlaps the surface of the connecting piece 23 facing the connection window 211. After completing step S3A, step S4 is executed.

[0058] S2B, the cover plate module 2 also includes an insulating component 24, which has a through structure 241 communicating with the connection window 211. The cover plate module 2 is placed on the side of the electrode group 100 where the electrode tab 200 is provided. The electrode tab 200 is bent so that the electrode tab 200 overlaps the surface of the connecting piece 23 facing the connection window 211. After completing step S2B, step S4 is executed.

[0059] S4. Weld the cover plate body 21 and the outer shell body 1 to close the outer shell body 1;

[0060] S5. Welding the tab 200 and the connecting piece 23 below the connection window 211;

[0061] S6. The closed module 3 includes a closed plate 31 and an insulating plate 32. The insulating plate 32 is located on the side of the closed plate 31 facing the tab 200. The closed plate 31 is located at the connection window 211 of the cover plate body 21, and the closed plate 31 is welded to the cover plate body 21.

[0062] This battery assembly method involves, on the one hand, wrapping an insulating film 5 around the surface of the electrode assembly 100 before it is inserted into the casing, and then setting a cover module 2 or a fixed end plate 4 that is heat-fused to the insulating film 5 on the side of the electrode assembly 100 where the electrode tabs 200 are located. This provides six-sided protection for the electrode assembly 100, preventing damage during insertion and improving product quality. On the other hand, during assembly, the welding process of the open part of the closed casing body 1 is placed before the welding process of the electrode tabs 200 and the connecting piece 23. This avoids the impact of vibration, high temperature, and other adverse factors during the welding process on the already welded electrode tabs 200 and connecting piece 23 when the casing body 1 is closed, thus improving the welding quality between the electrode tabs 200 and the connecting piece 23. Furthermore, since the cover module 2 is fixed to the casing body 1, the difficulty of welding the electrode tabs 200 and the connecting piece 23 is reduced.

[0063] The structure that is thermally fused with the insulating film 5 covering the outer side of the electrode group 100 is either a fixed end plate 4 or a cover plate module 2, which can be freely selected according to actual needs. In this embodiment, the fixed end plate 4 is preferred to be thermally fused with the insulating film 5 on the outer side of the electrode group 100. In other embodiments, in order to reduce manufacturing costs, the cover plate module 2 can be thermally fused with the insulating film 5.

[0064] Optionally, such as Figure 2 As shown, step S1 further includes the following steps:

[0065] S11, the battery also includes a base plate 6, which is pre-heat-melted onto the insulating film 5 at a predetermined position;

[0066] S12. Cover the insulating film 5 on the surface of the electrode group 100 where the tabs 200 are not provided, and make the base plate 6 cover the surface of the electrode group 100 away from the tabs 200.

[0067] By heat-melting the base plate 6 on the insulating film 5 before covering it, when the insulating film 5 is covered on the electrode assembly 100, the base plate 6 can cover the surface of the electrode assembly 100 and the tab 200 opposite to each other. This protects the surface of the electrode assembly 100 and the tab 200 opposite to each other when the electrode assembly 100 is put into the housing, thus preventing scratches during housing insertion.

[0068] Optionally, such as Figure 3 , Figure 4 , Figure 5 As shown, step S6 further includes the following steps:

[0069] S61. The cover plate body 21 is provided with a mounting boss 212 on the side away from the pole group 100. The mounting boss 212 is provided with mounting through holes 213 that communicate with the connection window 211 and are distributed in a stepped manner. A limiting step 214 is formed between the mounting through hole 213 and the connection window 211. The sealing plate 31 includes a sealing part 311 and a plug-in part 312. The insulating plate 32 is provided on the side of the plug-in part 312 away from the sealing part 311. The plug-in part 312 of the sealing plate 31 is inserted into the connection window 211. The sealing part 311 of the sealing plate 31 is inserted into the mounting through hole 213 and the sealing part 311 abuts against the limiting step 214.

[0070] S62. Weld the sealing part 311 to the cover plate body 21.

[0071] By setting a mounting boss 212 on the side of the cover plate body 21 away from the receiving cavity, and opening mounting through holes 213 on the mounting boss 212 that communicate with the connecting window 211 and are distributed in a stepped manner, the installation position of the sealing plate 31 is raised. On the one hand, more installation space is reserved for the electrode 200, which facilitates the subsequent welding of the electrode 200 and the connecting piece 23. On the other hand, the installation position of the electrode 200 in the height direction is improved, thereby further reducing the additional space occupied by the electrode 200 in the receiving cavity and further improving the space utilization rate.

[0072] Optionally, such as Figure 3 As shown, the width dimension of the overlap between the limiting step 214 and the closing part 311 along the first direction is W. When the closing part 311 and the cover plate body 21 are butt welded, the width dimension W satisfies 0.5mm≤W≤20mm.

[0073] When the sealing part 311 and the cover plate body 21 are butt-welded, the width W of the overlap between the limiting step 214 and the sealing part 311 along the first direction is limited to meet 0.5mm≤W≤20mm. On the one hand, this avoids the problem of small overlap width, which may lead to defects such as weld breakage and explosion during butt-welding. On the other hand, it avoids the problem of excessive overlap width, which may increase the overall size of the cover plate module 2 and increase additional costs.

[0074] Optionally, such as Figure 3 As shown, the overlap width between the limiting step 214 and the closing part 311 along the first direction is W. When the closing part 311 and the cover plate body 21 are through welded, the width W satisfies 1mm≤W≤20mm. By limiting the overlap width W of the limiting step 214 and the closing part 311 along the first direction when the closing part 311 and the cover plate body 21 are through welded, so that it satisfies 1mm≤W≤20mm, on the one hand, it avoids that if the overlap width is too small, the strength between the cover plate body 21 and the closing plate 31 will be insufficient after through weld, and the pressure test of 1.2MPa will not be met. On the other hand, it avoids that if the overlap width is too large, the overall size of the cover plate module 2 will increase, increasing additional costs.

[0075] In this embodiment, as Figure 2 As shown, a battery is also provided, which is assembled by influencing the battery assembly method described above. By applying the battery assembly method described above, the battery improves welding quality, thereby ensuring high conductivity, and improving power supply capacity and product quality.

[0076] Optionally, such as Figure 3 , Figure 7 , Figure 8As shown, the insulating plate 32 has a plug-in groove 321 on the side away from the sealing plate 31, and the insulating component 24 has a plug-in protrusion 242 on the side facing the cover plate body 21. The plug-in protrusion 242 is continuously arranged around the circumferential edge of the through structure 241 and is inserted into the plug-in groove 321.

[0077] By providing a plugging protrusion 242 on the insulating component 24 and a plugging groove 321 on the insulating plate 32, and by making the plugging groove 321 plug into the plugging protrusion 242, it is convenient to position and limit the insulating plate 32 and the insulating component 24 during assembly, ensuring the accuracy of the installation position. On the other hand, since both the insulating plate 32 and the insulating component 24 are insulating, the plugging protrusion 242 and the plugging groove 321 are plugged into to achieve multiple insulation, increase the insulation distance, prevent short circuits between the sealing plate 31, the cover plate body 21 and the metal parts inside the battery casing, and improve safety.

[0078] Optionally, such as Figure 9 As shown, the fixed end plate 4 is also provided with a shaping extension 42, which is located on the wall of the clearance groove 41. The angle between the direction of the shaping extension 42 and the wall is an acute angle. By providing the shaping extension 42 in the clearance groove 41 of the fixed end plate 4 and making the angle between the direction of the shaping extension 42 and the wall of the clearance groove 41 an acute angle, the direction of the shaping extension 42 can be in contact with the inclined surface of the tab 200 after it is closed, thereby achieving the effect of closing and fixing the tab 200 after it is closed, improving the closing state of the tab 200 and enhancing the closing effect.

[0079] Optionally, such as Figure 6 As shown, the connecting piece 23 includes a first connecting portion 231 and a second connecting portion 232. The first connecting portion 231 is connected to the pole post 22, and the second connecting portion 232 is connected to the electrode tab 200. A through-slot 233 is formed on the second connecting portion 232, through which the electrode tab 200 passes to connect with the second connecting portion 232. By forming the through-slot 233 on the second connecting portion 232, the shortest path is provided for the electrode tab 200 to pass through the connecting piece 23, thereby reducing the length of the electrode tab 200, minimizing its space occupation, and improving space utilization.

[0080] Optionally, the cross-section of the connecting piece 23 is Z-shaped or straight. To accommodate batteries of different specifications and models, in this embodiment, the surface of the first connecting portion 231 facing the cover body 21 is lower than the surface of the second connecting portion 232 facing the cover body 21, thus forming a Z-shaped connecting piece 23. By making the surface of the second connecting portion 232 higher than the surface of the first connecting portion 231, the connection position of the tab 200 is raised using the second connecting portion 232, thereby further reducing the additional space occupied by the tab 200 within the cavity and further improving space utilization.

[0081] In addition, the connecting piece 23 and the pole post 22 can be integrally formed by a molding process, or the connecting piece 23 and the pole post 22 can be manufactured separately and then welded together during assembly. In this embodiment, the pole post 22 and the connecting piece 23 are integral structures, and the second connecting portion 232 of the connecting piece 23 has a through groove 233.

[0082] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A battery assembly method, characterized in that, The battery assembled by the battery assembly method includes a pole group with tabs on the same side, a cover module, a housing body, a sealing module, and at most one fixed end plate. The battery assembly method includes the following steps: S1. Cover the outer surface of the electrode group without the electrode tab with an insulating film, and set the cover plate module or the fixed end plate that is heat-fused to the insulating film on the side of the electrode group with the electrode tab. If the fixed end plate is heat-fused to the electrode group, then execute step S2A; if the cover plate module is heat-fused to the electrode group, then execute step S2B. S2A: The fixed end plate is provided with a clearance groove for the electrode tab to pass through. The fixed end plate is placed on the side of the electrode assembly where the electrode tab is located, and the fixed end plate is heat-fused with the insulating film. After the fixed end plate and the insulating film are heat-fused, step S2A is completed, and step S3A is executed. S3A. The outer shell body is a single-sided open structure with a cavity. The electrode assembly with the fixed end plate hot-melted is inserted into the cavity inside the outer shell body. The cover plate module is set at the open part of the outer shell body. The cover plate module includes a cover plate body, an electrode post, and a connecting piece. The cover plate body has a connection window communicating with the cavity of the outer shell body. One end of the connecting piece is fixed to the cover plate body by the electrode post. The other end of the connecting piece extends to the bottom of the connection window. The fixed end plate has a clearance groove for the electrode tab to pass through. The electrode tab that passes through the clearance groove is bent so that the electrode tab overlaps the surface of the connecting piece facing the connection window. After completing step S3A, step S4 is executed. S2B. The cover plate module also includes an insulating component. The insulating component has a through structure that communicates with the connection window. The cover plate module is placed on the side of the electrode group where the electrode lug is located. The electrode lug is bent so that the electrode lug overlaps the surface of the connecting piece facing the connection window. After completing step S2B, step S4 is executed. S4. Weld the cover plate body to the outer shell body to seal the outer shell body; S5. Weld the electrode tab facing the connection window to the connection piece; S6. The sealing module includes a sealing plate and an insulating plate. The insulating plate is disposed on the side of the sealing plate facing the electrode tab. The sealing plate is disposed at the connection window of the cover plate body, and the sealing plate is welded to the cover plate body. Step S6 also includes the following steps: S61. The cover plate body is provided with a mounting boss on the side away from the pole group. The mounting boss is provided with mounting through holes that communicate with the connection window and are distributed in a stepped manner. A limiting step is formed between the mounting through holes and the connection window. The sealing plate includes a sealing part and a plug-in part. The insulating plate is provided on the side of the plug-in part away from the sealing part. The plug-in part of the sealing plate is inserted into the connection window. The sealing part of the sealing plate is inserted into the mounting through hole and the sealing part abuts against the limiting step. S62. Weld the sealing part to the cover plate body; The width dimension of the overlap between the limiting step and the closing part along the first direction is W. When the closing part and the cover plate body are welded together, the width dimension W satisfies 0.5mm≤W≤20mm. When the closure part is welded to the cover plate body through the weld, the width dimension W satisfies 1mm≤W≤20mm; The insulating plate has a insertion groove on the side away from the sealing plate, and the insulating component has an insertion protrusion on the side facing the cover plate body. The insertion protrusion is continuously arranged around the circumferential edge of the through structure and is inserted into the insertion groove. The fixed end plate is also provided with a shaping extension edge, which is provided on the wall surface of the clearance groove, and the angle between the direction of the shaping extension edge and the wall surface is an acute angle.

2. The battery assembly method according to claim 1, characterized in that, Step S1 also includes the following steps: S11. The battery also includes a base plate, which is pre-heat-melted at a predetermined position on the insulating film. S12. The insulating film is wrapped around the surface of the electrode group where the tabs are not provided, and the base plate is used to cover the surface of the electrode group away from the tabs.

3. A battery, characterized in that, The battery is assembled using the battery assembly method as described in any one of claims 1-2.

4. The battery according to claim 3, characterized in that, The connecting piece includes a first connecting part and a second connecting part. The first connecting part is connected to the pole post, and the second connecting part is connected to the pole tab. The second connecting part has a through-slot, and the pole tab passes through the through-slot and connects to the second connecting part.

5. The battery according to claim 3, characterized in that, The cross-section of the connecting piece is Z-shaped or straight.

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