Adapter forming process, battery assembly process, and single battery

Abstract

The application belongs to the technical field of batteries, and discloses a switching piece forming process, a battery assembling process and a single battery. The switching piece forming process comprises the following steps: S1, punching: punching a metal foil sheet with a required thickness according to a preset size to obtain a plurality of metal foil layers; S2, stacking: stacking a preset number of metal foil layers to make them meet a preset thickness to obtain a metal stack layer; and S3, welding: performing straight pressure ultrasonic welding on a to-be-fixed region near two ends of the metal stack layer until the plurality of metal foil layers near the two end regions of the metal stack layer are fixedly connected. The battery assembling process comprises the following steps: S10, welding the core once; S20, welding twice; S30, welding the core of the cell group; and S40, forming into a shell. The application can realize the manufacturing and forming of the switching piece with low-cost soft connection, simplifies the manufacturing steps, saves the cost, reduces the size of the single battery in the width direction, improves the space utilization and energy density of the single battery, and increases the overcurrent area of the switching piece.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to an adapter plate forming process, a battery assembly process, and a single cell. Background Technology

[0002] Prismatic batteries, a common battery structure, mainly consist of cells, adapter plates, a top cover, and a casing. The cells are housed within the casing, the top cover is sealed at the casing opening, and the adapter plates connect the cell's tabs to the corresponding terminals on the top cover. Therefore, the adapter plates are the primary current-carrying structure in prismatic batteries. Currently, energy density and safety are key concerns in the prismatic battery field.

[0003] In existing prismatic batteries, the tabs of the cells are typically located on the top of the cell or on both sides along its width. Therefore, the adapter piece is usually placed on the top of the cell or connected at one end to the side of the cell along its width and at the other end to the top cover. When welding the adapter piece to the tabs, because the adapter piece is a rigid connector, a gap must be left between the tab and the cell body to accommodate a spacer for welding. This results in some wasted space along the width of the prismatic battery, reducing space utilization and thus lowering energy density. If the adapter piece were a flexible connector, the existing manufacturing process for flexible connectors is complex and costly. If used for electrical connections inside prismatic batteries, it could increase the cost of the prismatic battery itself, significantly increasing the cost of the battery system.

[0004] Therefore, there is an urgent need for a connector forming process, a battery assembly process, and a single cell to solve the above-mentioned technical problems. Summary of the Invention

[0005] One object of the present invention is to provide a molding process for an adapter piece that enables the manufacturing of a low-cost flexible connector adapter piece, simplifies the manufacturing steps, and saves costs.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] The adapter plate molding process, used for molding adapter plates for flexible connections, includes the following steps:

[0008] S1. Punching: Punching a metal foil sheet of the required thickness to a preset size to obtain multiple metal foil layers;

[0009] S2, Stacking: Stack a preset number of metal foil layers to meet a preset thickness to obtain a metal stack;

[0010] S3. Welding: Perform direct pressure ultrasonic welding on the areas to be fixed near both ends of the above-mentioned metal stack until multiple metal foil layers near both ends of the above-mentioned metal stack are fixedly connected.

[0011] Optionally, in step S3, before performing direct pressure ultrasonic welding on the area to be fixed, the multiple metal foil layers in the area to be fixed need to be shaped and flattened.

[0012] Optionally, in step S3, the number of times the above-mentioned area to be fixed is subjected to direct pressure ultrasonic welding is N, N≥1, and N is a positive integer; when N>1, after each direct pressure ultrasonic welding is completed, the above-mentioned area to be fixed needs to be translated along a preset path.

[0013] The beneficial effects of the adapter plate forming process provided by this invention are as follows: by using direct pressure ultrasonic welding instead of diffusion welding, the processing cost of the adapter plate for flexible connections is reduced, and subsequent processing processes such as polishing are eliminated, simplifying the manufacturing process, further reducing the processing cost of the adapter plate for flexible connections, and improving the processing efficiency of the adapter plate for flexible connections.

[0014] Another objective of this invention is to provide a battery assembly process that can reduce the width dimension of a single battery cell, improve the space utilization and energy density of the single battery cell, and increase the flow area of ​​the adapter plate.

[0015] To achieve this objective, the present invention adopts the following technical solution:

[0016] A battery assembly process is used to assemble two A-group cells with two double-sided tabs and two B-group cells with two double-sided tabs to a top cover through corresponding adapter pieces. The A-group cells and the B-group cells are mirror images of each other. The adapter pieces are manufactured using the aforementioned adapter piece forming process. The adapter pieces include a bent portion and a first connecting portion and a second connecting portion disposed at both ends of the bent portion.

[0017] The above battery assembly process includes the following steps:

[0018] S10, One-time welding of cores: Place two cells in the same group horizontally, bring the first tabs of the two cells close together and weld them to the first connecting part of the corresponding adapter piece, and weld the second tab of any one of the cells in the same group to the first connecting part of the corresponding adapter piece; and set the two cells in the same group together after welding.

[0019] S20, Secondary welding: The second tabs of the two cells in the same group are bent so that the unconnected second tabs and the first connecting part of the corresponding adapter piece are superimposed to form a welding area. Welding fixtures are set on both sides of the welding area and the welding area is welded to obtain the formed A group cells and the formed B group cells.

[0020] S30, Cell assembly welding and core joining: The formed A group cell and the formed B group cell are placed horizontally, and the second connecting parts of the adapter piece of the same polarity are brought close to each other and welded to the pole of the same polarity in the top cover; the welded A group cell and B group cell are joined together to obtain a pre-assembled cell assembly.

[0021] S40, Housing Molding: The pre-assembled battery cells are placed into the housing, and the housing and top cover are welded together.

[0022] Optionally, in step S10, the process of combining two of the above-mentioned battery cells that have been welded together includes: bending the body portion of each of the above-mentioned battery cells along the root of the corresponding first electrode tab until the first electrode tab is attached to the body portion.

[0023] Optionally, in step S20, after bending the second tabs of two cells in the same group, a gap is provided between the body of each cell and the bent second tab to accommodate the welding fixture.

[0024] Optionally, in step S10, after the two welded cells of the same group are combined, the method further includes: bending the first connecting portion and the bent portion of the adapter piece at the first electrode tab; and / or,

[0025] Step S20, after bending the second tabs of the two cells in the same group, further includes: bending the first connecting portion and the bent portion of the adapter piece at the second tab; and / or,

[0026] In step S30, after the welded A group battery cells and B group battery cells are combined and set up, the method further includes: bending the second connecting part and the bending part of all the above-mentioned adapter pieces.

[0027] Optionally, in step S10, the first electrode tab and the first connecting portion of the corresponding adapter piece, as well as the second electrode tab and the first connecting portion of the corresponding adapter piece, are ultrasonically welded; and / or,

[0028] In step S20, the second electrode tab and the corresponding first connecting portion of the adapter piece are laser welded together; and / or,

[0029] In step S30, the second connecting portions of the two aforementioned adapter plates of the same polarity and the corresponding aforementioned pole posts are laser welded together.

[0030] Optionally, before step S10, step S05, pre-welding and cutting of the tabs, is also included: the tabs at both ends of the cell are gathered and welded together, and then the length of the tabs is shaped and cut.

[0031] The beneficial effects of the battery assembly process provided by this invention are as follows: By using a flexible connector adapter, and during the process of welding and fixing the A group cells and B group cells to the adapter, the first connecting part and the first tab are welded first and then the cores are joined, and then the adapter is bent. This ensures that there is no gap between the first tab and the cell body after bending, reducing unnecessary space, improving the space utilization and energy density of the single cell, and the adapter is located on the large surface of the single cell, which also provides space for increasing the current flow area of ​​the adapter.

[0032] Another objective of this invention is to provide a single-cell battery that can increase the current-carrying area of ​​the adapter plate, improve space utilization and energy density, and has better thermal conductivity, thereby improving the temperature uniformity of the single-cell battery.

[0033] To achieve this objective, the present invention adopts the following technical solution:

[0034] Individual cells are assembled using the battery assembly process described above.

[0035] The beneficial effects of the single-cell battery provided by this invention are as follows: By placing the adapter plate between the cell assembly on either side of its thickness direction and the inner wall of the casing, i.e., placing the adapter plate on the large surface of the cell, the adapter plate can increase its width dimension when increasing its current-carrying area, without needing to increase its thickness dimension. This arrangement eliminates the need for additional space, utilizes the existing space, improves the space utilization rate of the single-cell battery, thereby increasing the energy density of the single-cell battery, and also increases the current-carrying area of ​​the adapter plate. Furthermore, the battery assembly process in this embodiment reduces the space in the width direction of the single-cell battery, further improving the energy density of the single-cell battery. Attached Figure Description

[0036] Figure 1 This is a front view of the adapter plate provided in a specific embodiment of the present invention;

[0037] Figure 2 This is an isometric view of a single battery cell provided in a specific embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the pre-welded and cut electrode tab structure provided in a specific embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of the structure of single welding of battery cells in the same group provided in a specific embodiment of the present invention;

[0040] Figure 5 This is a schematic diagram of the structure of a single-stage merging of battery cells in the same group provided in a specific embodiment of the present invention;

[0041] Figure 6This is a schematic diagram of the adapter plate bending once according to a specific embodiment of the present invention;

[0042] Figure 7 This is a schematic diagram of the secondary welding structure of the same group of battery cells provided in a specific embodiment of the present invention;

[0043] Figure 8 yes Figure 7 A magnified view of a section at point A in the middle;

[0044] Figure 9 yes Figure 7 A magnified view of a section at point B in the middle;

[0045] Figure 10 This is a schematic diagram of the cell assembly welding structure provided in a specific embodiment of the present invention;

[0046] Figure 11 This is a schematic diagram of the structure of the battery cell assembly after welding and joining, provided in a specific embodiment of the present invention.

[0047] In the picture:

[0048] 11. Group A battery cell; 12. Group B battery cell; 101. First tab; 102. Second tab; 103. Body section;

[0049] 2. Adapter piece; 201. Bending part; 202. First connecting part; 203. Second connecting part;

[0050] 3. Top cover; 301. Terminal post;

[0051] 4. Shell;

[0052] 5. Welding fixtures. Detailed Implementation

[0053] 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.

[0054] 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 direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0055] 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.

[0056] In the description of this embodiment, the terms "upper," "lower," "left," "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.

[0057] This embodiment provides a molding process for an adapter piece, which is used to manufacture the adapter piece 2 for flexible connections.

[0058] Please refer to Figure 1 It should be noted that the flexible connector 2 includes a bending portion 201, a first connecting portion 202, and a second connecting portion 203. The first connecting portion 202 and the second connecting portion 203 are respectively disposed at both ends of the bending portion 201. The bending portion 201 can be bent to realize the flexible connection of the connector 2. The first connecting portion 202 and the second connecting portion 203 are rigid connections used for electrical connection with external structures, thereby realizing the connecting function of the connector 2.

[0059] Specifically, the adapter molding process includes:

[0060] Step S1, punching: punch the metal foil sheet of the required thickness according to the preset size to obtain multiple metal foil layers; that is, according to the existing connection position, the metal foil layer is cut so that the metal foil layer meets the shape when the adapter piece 2 is fully unfolded, so that the adapter piece 2 can be electrically connected to other structures in the subsequent bending situation.

[0061] It is understood that the above-mentioned preset dimensions are the shape of the adapter piece 2 when it is fully unfolded, that is, a planar shape. The specific shape can be adapted to actual needs and is not specifically limited here.

[0062] Step S1 is followed by step S2, stacking: stacking a preset number of metal foil layers to meet a preset thickness to obtain a metal stack; and placing it in an unfixed state of the adapter piece 2. At this time, each position of the metal stack can achieve a soft connection such as bending.

[0063] It is understood that the preset thickness of the adapter piece 2 is the thickness designed to meet the required flow area, and the preset quantity is calculated based on the preset thickness and the thickness of a single metal foil layer. Both of these can be adapted to actual needs and are not specifically limited here.

[0064] Optionally, the adapter 2 in this embodiment is applied in a single battery cell. Therefore, the metal foil layer can be copper foil or aluminum foil. The thickness of the copper adapter 2 can be selected from 0.8mm to 1.5mm, and the thickness of the aluminum adapter 2 can be selected from 1mm to 2mm. These are the commonly used thicknesses of the copper adapter 2 and the aluminum adapter 2. If the width of the adapter 2 changes, its thickness may also change accordingly.

[0065] Step S2 is followed by step S3, welding: direct pressure ultrasonic welding is performed on the areas to be fixed near both ends of the metal stack until multiple metal foil layers near both ends of the metal stack are fixedly connected; thus, the metal stack is fixed, thereby forming the first connecting part 202 and the second connecting part 203 of the adapter piece 2, and the area that is not welded and fixed is the bending part 201.

[0066] Optionally, in step S3, before performing direct pressure ultrasonic welding on the area to be fixed, the multiple metal foil layers of the area to be fixed need to be shaped and flattened to facilitate subsequent welding, so as to achieve better welding results and avoid problems such as local missed welding.

[0067] Optionally, in step S3, the number of times the direct pressure ultrasonic welding is performed on the area to be fixed is N, where N≥1 and N is a positive integer; when N>1, after each direct pressure ultrasonic welding, the area to be fixed needs to be translated along a preset path. This setting further enhances the fixing effect on the first connecting part 202 and the second connecting part 203, avoiding the situation where the weld area is insufficient due to the large area of ​​the first connecting part 202 and the second connecting part 203. Through multiple translations and welding, the weld marks are evenly distributed throughout the entire area to be fixed, thereby obtaining the first connecting part 202 and the second connecting part 203 with better fixing effect.

[0068] The adapter plate forming process in this embodiment uses direct pressure ultrasonic welding instead of diffusion welding, which reduces the processing cost of the flexible connector adapter plate 2 and eliminates the need for subsequent processing such as polishing, simplifying the manufacturing process, further reducing the processing cost of the flexible connector adapter plate 2, and improving the processing effect of the flexible connector adapter plate 2.

[0069] This embodiment also provides a single-cell battery, which is assembled using the battery assembly process described in this embodiment.

[0070] Please refer to Figure 2 Specifically, the single battery includes a casing 4, two A-group cells 11 with double-sided tabs, two B-group cells 12 with double-sided tabs, a cover plate, and four adapter plates 2. Each cell is provided with an adapter plate 2. The two A-group cells 11 and the two B-group cells 12 are connected together through the adapter plates 2 to form a cell group. The cell group is disposed inside the casing 4. The cover plate is sealed at the opening of the casing 4. The cover plate structure is provided with two terminals 301. The two terminals 301 are electrically connected to the two tabs of each cell one-to-one through the corresponding adapter plates 2. The adapter plates 2 are disposed between the cell group on any side along its own thickness direction and the inner wall of the casing 4.

[0071] In this embodiment, the single-cell battery has an adapter plate 2 positioned between the cell assembly on either side of its thickness direction and the inner wall of the casing 4. This means the adapter plate 2 is positioned on the large surface of the cell. This allows the adapter plate 2 to increase its width when its current-carrying area increases, without needing to increase its thickness. This arrangement eliminates the need for additional space, utilizing existing space effectively and improving the space utilization rate of the single-cell battery, thereby increasing its energy density. It also increases the current-carrying area of ​​the adapter plate 2. Furthermore, the heat from the adapter plate 2 can be transferred to the casing 4 or cover structure in various directions of the cell, facilitating timely heat dissipation when an external thermal management device exchanges heat with the cell, thus improving the temperature uniformity and heat dissipation effect of the single-cell battery.

[0072] Specifically, each battery cell includes a body portion 103, a first electrode 101, and a second electrode 102. The first electrode 101 and the second electrode 102 are respectively disposed on both sides of the body portion 103. Either the first electrode 101 or the second electrode 102 is a positive electrode, and the other is a negative electrode, thereby enabling the battery cell to be connected to the external power supply.

[0073] In some embodiments, the adapter piece 2 is L-shaped. This configuration allows the adapter piece 2 to pass through the large surface of the cell and bend to the corresponding first connecting portion 202 and second connecting portion 203, thereby achieving electrical connection between the adapter piece 2 and the corresponding tab and terminal 301, thus realizing the function of the adapter piece 2 in connecting electrical connections. Furthermore, the large surface configuration allows the adapter piece 2 to have more ample width space, thereby increasing its width dimension and increasing the current-carrying area of ​​the adapter piece 2, thereby improving the current-carrying capacity of the single battery cell.

[0074] Please refer to Figures 2 to 11This embodiment also provides a battery assembly process for assembling two A-group cells 11 with two double-sided tabs and two B-group cells 12 with two double-sided tabs to a top cover 3 via corresponding adapter pieces 2. The A-group cells 11 and B-group cells 12 are mirror images of each other. The adapter pieces 2 are manufactured using the adapter piece forming process described in any of the above schemes. The adapter pieces 2 include a bending portion 201 and a first connecting portion 202 and a second connecting portion 203 disposed at both ends of the bending portion 201.

[0075] Specifically, the battery assembly process includes the following steps:

[0076] Please refer to Figures 4 to 6 Step S10, First-time welding and core joining: Place two cells of the same group horizontally, bring the first tabs 101 of the two cells together and weld them to the first connecting part 202 of the corresponding adapter piece 2, and weld the second tab 102 of any cell in the same group to the first connecting part 202 of the corresponding adapter piece 2; then join the two cells of the same group after welding. This step involves welding and joining cells 11 of group A and cells 12 of group B together in one step. This arrangement ensures that the welding of a set of tabs of the same polarity (i.e., the first tabs 101 of the two cells) and the adapter piece 2 is completed before the cells of the same group are joined together, eliminating the need for welding after joining. This reduces unnecessary space for tab welding and improves the space utilization rate of the single battery cell.

[0077] Please refer to 6 and Figure 8 Specifically, in step S10, the joining of two welded cells in the same group includes: bending the body portion 103 of each cell along the root of the corresponding first tab 101 until the first tab 101 is in contact with the body portion 103. This ensures that after the first tab 101 of the cell is bent, there is no gap between the first tab 101 and the body portion 103, thereby reducing the size of the cell in the width direction and improving the space utilization and energy density of the single battery cell.

[0078] Optionally, in step S10, the first electrode 101 and the first connecting part 202 of the corresponding adapter piece 2, as well as the second electrode 102 and the first connecting part 202 of the corresponding adapter piece 2, are ultrasonically welded. This process is simple, the welding effect is better, and it is more suitable for thin products.

[0079] In some embodiments, after the two cells in the same group are welded together in step S10, the method further includes: bending the first connecting portion 202 and the bending portion 201 of the adapter piece 2 at the first tab 101; that is, setting the adapter piece 2 on the large surface of the cell can increase the width space of the adapter piece 2 and improve the current flow area of ​​the adapter piece 2, without adding extra space, thereby improving the space utilization and energy density of the single battery.

[0080] In some embodiments, the process before step S10 includes preliminary preparations: preparing group A cells 11, group B cells 12, housing 4, cover plate and adapter plate 2.

[0081] Specifically, the preparation of group A cell 11, group B cell 12, housing 4, and cover plate can be carried out using common preparation methods, which will not be elaborated here. The adapter piece 2 is prepared using the adapter piece molding process described in any of the above schemes of this embodiment.

[0082] Please refer to Figure 3 Optionally, before step S10, step S05, pre-welding and cutting of the tabs, is included: the tabs at both ends of the cell are gathered and welded together, and then the length of the tabs is shaped and cut. That is, after the cell is prepared, a stacked cell assembly consisting of a positive electrode, a separator, and a negative electrode can be obtained. Then, the tab portion of the stacked cell assembly needs to be pre-welded and cut to bring together and fix the first tab 101 and the second tab 102 of the cell.

[0083] Please refer to Figure 7 and Figure 9 Following step S10, step S20, secondary welding, is also included: bending the second tabs 102 of the two cells in the same group so that the unconnected second tabs 102 overlap with the first connecting portion 202 of the corresponding adapter piece 2 to form a welding area. Welding fixtures 5 are set on both sides of the welding area and welded to the welding area to obtain the formed A-group cell 11 and the formed B-group cell 12. This step involves secondary welding of the A-group cell 11 and the B-group cell 12 respectively. This setup allows the second tabs 102 of the cells in the same group to be welded together. During welding, since the two cells in the same group have already been combined, space must be left for the placement of the welding fixture 5 to support the second tabs 102 and the corresponding adapter piece 2.

[0084] Specifically, in step S20, after bending the second tabs 102 of the two cells in the same group, a gap is provided between the body part 103 of each cell and the bent second tab 102 to place the welding fixture 5.

[0085] Optionally, the welding fixture 5 includes a pad and a pressure block. The pad is disposed between the adapter plate 2 and the main body 103 of the battery cell, and the pressure block is disposed on the side of the second electrode 102 away from the main body 103 to support the adapter plate 2 and the second electrode 102, thereby improving the reliability of welding the second electrode 102 and the adapter plate 2.

[0086] Optionally, in step S20, the second electrode 102 and the first connecting part 202 of the corresponding adapter piece 2 are laser welded together, which has a better welding effect and higher efficiency.

[0087] In some embodiments, step S20, after bending the second tabs 102 of the two cells in the same group, further includes: bending the first connecting portion 202 and the bending portion 201 of the adapter piece 2 at the second tab 102; that is, setting the adapter piece 2 at the large surface of the cell can increase the width space of the adapter piece 2, improve the current flow area of ​​the adapter piece 2, and at the same time, it will not increase the extra space, thereby improving the space utilization and energy density of the single battery.

[0088] Please refer to Figure 10 and Figure 11 After step S20, step S30 is also included: welding and assembling the battery cells: the formed A group battery cells 11 and the formed B group battery cells 12 are placed horizontally, and the second connecting part 203 of the same polarity adapter piece 2 is brought close to each other and welded to the same polarity pole post 301 in the top cover 3; the welded A group battery cells 11 and B group battery cells 12 are assembled to obtain a pre-assembled battery cell group; that is, by connecting the A group battery cells 11 and B group battery cells 12 with the same polarity and then performing the assembling process, the pre-assembly of the battery cell group can be achieved.

[0089] Optionally, in step S30, the second connecting part 203 of the two adapter pieces 2 of the same polarity and the corresponding pole post 301 are laser welded together, which has a better welding effect and higher efficiency.

[0090] In some embodiments, after the welded A group cells 11 and B group cells 12 are combined and set up in step S30, the method further includes bending all the second connecting portions 203 and bending portions 201 of the adapter pieces 2. This involves placing the adapter piece 2 on the larger surface of the cell, which increases the width of the adapter piece 2 and improves its current-carrying area without adding extra space, thus improving the space utilization and energy density of the single battery cell.

[0091] Optionally, after step S30, step S35 is also included: covering the pre-assembled battery cell assembly with an insulating film so that the pre-assembled battery cell assembly is insulated from the outside world, thereby facilitating the subsequent battery cell assembly casing molding operation.

[0092] Please refer to Figure 2 After step S30, step S40 is also included: casing forming: the pre-assembled cell group is placed into the casing 4, and the casing 4 and the top cover 3 are welded together to complete the assembly of the single cell, which improves the energy density and space utilization of the single cell.

[0093] In this embodiment, the battery assembly process employs a flexible connector 2. During the welding and fixing of the A group cell 11 and the B group cell 12 to the connector 2, the first connecting part 202 and the first tab 101 are welded together first, then the cores are joined, and then the connector 2 is bent. This ensures that there is no gap between the first tab 101 and the cell body 103 after bending, reducing unnecessary space and improving the space utilization and energy density of the single battery. Furthermore, since the connector 2 is located on the large surface of the single battery, it also provides space for increasing the current flow area of ​​the connector 2.

[0094] 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 process, characterized in that, The A-group battery cell (11) with two double-sided tabs and the B-group battery cell (12) with two double-sided tabs are assembled with the top cover (3) through the corresponding adapter piece (2). The A-group battery cell (11) and the B-group battery cell (12) are mirror images of each other. The adapter piece (2) is manufactured by the adapter piece forming process. The adapter piece forming process includes the following steps: S1, punching: punching the metal foil sheet of the required thickness according to the preset size to obtain multiple metal foil layers. S2, Stacking: Stack a preset number of metal foil layers to meet the preset thickness to obtain a metal stack; S3, Welding: Perform direct pressure ultrasonic welding on the areas to be fixed near both ends of the metal stack until multiple metal foil layers near both ends of the metal stack are fixedly connected; The adapter piece (2) includes a bending part (201) and a first connecting part (202) and a second connecting part (203) disposed at both ends of the bending part (201). The battery assembly process includes the following steps: S10, First welding of cores: Place two cells in the same group horizontally, bring the first tabs (101) of the two cells close together and weld them to the first connecting part (202) of the corresponding adapter piece (2), and weld the second tab (102) of any one of the cells in the same group to the first connecting part (202) of the corresponding adapter piece (2); and set the two cells in the same group together after welding. S20, Secondary welding: The second tabs (102) of the two cells in the same group are bent so that the unconnected second tabs (102) and the first connecting part (202) of the corresponding adapter piece (2) are superimposed to form a welding area. Welding fixtures (5) are set on both sides of the welding area and the welding area is welded to obtain the formed A group cell (11) and the formed B group cell (12). S30, Welding and joining the battery cells: Place the formed A group battery cells (11) and the formed B group battery cells (12) horizontally, and bring the second connecting part (203) of the same polarity adapter piece (2) together and weld it to the same polarity pole post (301) in the top cover (3); Join the welded A group battery cells (11) and B group battery cells (12) to obtain a pre-assembled battery cell group; S40, Housing Forming: Place the pre-assembled battery cell assembly into the housing (4), and weld the housing (4) and the top cover (3). In step S10, the process of combining two battery cells that have been welded together includes: bending the body portion (103) of each battery cell along the root of the corresponding first tab (101) until the first tab (101) is attached to the body portion (103).

2. The battery assembly process according to claim 1, characterized in that, In step S3, before performing direct pressure ultrasonic welding on the area to be fixed, the multiple metal foil layers in the area to be fixed need to be shaped and flattened.

3. The battery assembly process according to claim 1, characterized in that, In step S3, the number of times the direct pressure ultrasonic welding is performed on the area to be fixed is N, where N≥1 and N is a positive integer; when N>1, the area to be fixed needs to be translated along a preset path after each direct pressure ultrasonic welding is completed.

4. The battery assembly process according to claim 1, characterized in that, In step S20, after bending the second tabs (102) of the two cells in the same group, a gap is provided between the body part (103) of each cell and the bent second tab (102) to place the welding fixture (5).

5. The battery assembly process according to claim 1, characterized in that, In step S10, after the two welded battery cells in the same group are combined, the method further includes: bending the first connecting portion (202) and the bending portion (201) of the adapter piece (2) at the first electrode tab (101); and / or, In step S20, after bending the second tabs (102) of the two cells in the same group, the method further includes: bending the first connecting portion (202) and the bent portion (201) of the adapter piece (2) at the second tab (102); and / or, In step S30, after the welded A group battery cell (11) and B group battery cell (12) are combined and set together, the step further includes bending the second connecting part (203) and the bending part (201) of all the adapter pieces (2).

6. The battery assembly process according to claim 1, characterized in that, In step S10, the first electrode tab (101) and the first connecting portion (202) of the corresponding adapter piece (2), as well as the second electrode tab (102) and the first connecting portion (202) of the corresponding adapter piece (2), are ultrasonically welded; and / or, In step S20, the second electrode tab (102) and the first connecting portion (202) of the corresponding adapter piece (2) are laser welded together; and / or, In step S30, the second connecting part (203) of the two adapter pieces (2) of the same polarity and the corresponding pole piece (301) are laser welded together.

7. The battery assembly process according to claim 1, characterized in that, Before step S10, there is also S05, pre-welding and cutting of the tabs: the tabs at both ends of the battery cell are gathered and welded together, and then the length of the tabs is shaped and cut.

8. A single-cell battery, characterized in that, The battery is assembled using the battery assembly process described in any one of claims 1-7.

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