Battery cell forming process and battery cell
By designing the positive and negative ears of the battery cell body in the battery cell molding process, and using technical means such as S-angle position and porous insulating plate, the shortcomings of the existing batteries in charge and discharge efficiency, heat dissipation effect and deformation of the electrode position are solved, and more efficient battery performance and stronger current channel capabilities are achieved.
Patent Information
- Application Number
- CN202510248067.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-04
- Publication Date
- 2025-06-03
AI Technical Summary
The existing large-capacity square batteries have shortcomings in charging and discharging efficiency, heat dissipation effect and deformation of the pole ear, resulting in poor battery performance and short-circuiting of the pole plate.
A battery cell forming process is adopted, through the steps of roll preparation, die cutting, lamination, tape fixing, hot pressing and shaping, and current collecting belt welding, the positive electrode ear and negative electrode ear of the battery cell main body are placed on opposite sides, and the porous insulating plate is used to design the pole plate at the S-angle position and the porous insulating plate to increase the contact area between the current collecting belt and the electrode ear.
It improves the charging and discharging efficiency and performance of the battery, uniforms the heat dissipation inside the battery, avoids the secondary bending of the pole position and is pressed down under force, reduces the internal resistance of the battery and enhances the ability of the current channel.
Smart Images
Figure CN120089776A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of battery production and manufacturing processes, and particularly to a core forming process and a core Background Art
[0002] A secondary battery, also known as a rechargeable battery or a storage battery, is a battery that can be reactivated by charging after discharging and continue to be used. It utilizes the reversibility of chemical reactions to achieve the conversion between electrical energy and chemical energy, thereby achieving the purpose of storing and releasing electrical energy. Currently, secondary batteries are mainly divided into types such as lead-acid batteries, lithium-ion batteries, and sodium-ion batteries.
[0003] The production and preparation process of a battery mainly includes a front-end process manufacturing section, a middle-end process assembly section, and a back-end process testing section. In the prior art, in the front-end process manufacturing section, the development direction of the design of large-capacity square batteries mainly focuses on aspects such as improving performance, reducing costs, enhancing safety, and optimizing system integration.
[0004] However, the batteries manufactured by the winding process adopted by most current manufacturers have the following several disadvantages. First, due to the use of a single tab to output current, the internal resistance is relatively high, affecting the charge and discharge efficiency and performance of the battery, and the heat dissipation effect is not good. Second, the internal structure and mechanical properties of the battery manufactured by the winding process show a gradient change, the heat dissipation direction is uneven, and it is easy to have a temperature gradient distribution, resulting in a relatively fast capacity decay and a short cycle life during long-term use of the battery. There are also a small number of manufacturers using the stacking process whose pole piece design adopts a single R-angle punching and forming method, which also has the following defects. First, the positive and negative tab positions are drained in the same direction, the tab position size is small, the diversion effect of the diversion connection piece is poor, the tab position is prone to heat generation, and power consumption loss is formed during the integrated PACK application. Moreover, when the battery cover is combined and welded, the battery cover is bent towards the core body under force, resulting in the battery cover contacting the positive and negative tabs, thus forming a secondary bending force and pressure on the tab position, which is prone to cause poor conditions such as short circuit and deformation of the pole piece due to force. Summary of the Invention
[0005] In order to improve the charge and discharge efficiency and performance of the battery, improve the heat dissipation effect of the core, and avoid the deformation of the tab position caused by the welding of the battery cover, this application provides a core forming process and a core.
[0006] The core forming process and the core provided by this application adopt the following technical solutions: In a first aspect, this application provides a core forming process.
[0007] A core forming process includes: Preparation of coiled material; Manufacture and die-cut, slit the roll material into intermediates with a specified width, and process the intermediates to obtain a positive electrode sheet and a negative electrode sheet with specified dimensions of tab ears and tab ear spacing; Stack the sheets, stack them in order along the thickness direction of the positive electrode sheet in the order of the positive electrode sheet, the separator, and the negative electrode sheet, and make the positive tab ear and the negative tab ear on the battery cell body on opposite sides; Fix with adhesive tape, fix the top and bottom of the battery cell body with insulating adhesive tape to obtain the battery cell body; Hot press and shape, perform hot press and shaping on the battery cell body to eliminate the wrinkles of the separator to discharge the air inside the battery cell body, and make the separator closely adhere to the positive electrode sheet and the negative electrode sheet; Weld the current collector strip, weld and fix the horizontal section of the current collector strip to the pole post of the battery cover plate, and weld and fix the vertical section of the current collector strip to the tab ear on the battery cell body.
[0008] By adopting the above technical scheme, the active material powder, binder, conductive agent and solvent are first mixed in a certain order and under certain conditions to form a stable suspension. This process requires strict control of parameters such as stirring speed, temperature, vacuum degree, etc. to ensure the dispersion uniformity and stability of the slurry. Then the positive (negative) suspension slurry is evenly coated on the aluminum foil (copper foil) surface and then dried to form a film. Then, the active material is closely contacted with the current collector by rolling, which reduces the moving distance of electrons, reduces the thickness of the pole piece, increases the filling amount, and at the same time The internal resistance of the battery is reduced and the conductivity is increased; according to the process and the size of the incoming material, the film roll is cut into multiple rolls of the same size using a slitting machine, and then the roll is cut into intermediates of specified widths, and the intermediates are processed to obtain positive and negative electrodes with specified sizes of tabs and tab spacing; the positive electrode sheet, the separator and the negative electrode sheet are stacked in order along the thickness direction of the positive electrode sheet, and the positive and negative tabs on the battery body are on opposite sides; then the battery body is fixed with two layers of high-temperature insulating tape on the top and bottom The battery cell body is obtained, and then the battery cell body is hot-pressed and shaped to eliminate the diaphragm wrinkles to discharge the air inside the battery cell body, so that the diaphragm and the positive and negative electrodes are closely attached; the horizontal section of the collector belt is welded and fixed to the battery cover plate pole, and the vertical section of the collector belt is welded and fixed to the pole ear on the battery cell body; the collector belt is welded, the horizontal section of the collector belt is welded and fixed to the battery cover plate pole, and the vertical section of the collector belt is welded and fixed to the pole ear on the battery cell body; the designed battery cell forming process, by arranging the positive and negative pole ears of the battery cell body on opposite sides, The following effects can be achieved. First, the shape characteristics of the battery cell can be used to avoid the narrow space on the top of the battery cell body, thereby increasing the original size of the positive and negative ears, thereby reducing resistance, reducing heat and improving the charging and discharging efficiency and performance of the battery. Secondly, the positive and negative ears are drained in different directions, which can make the heat inside the battery dissipate evenly and avoid heat concentration and the defect of temperature gradient distribution. Finally, it can also avoid the secondary bending of the ear position and the downward pressure when assembling and welding the battery cover, which will cause defects such as short circuit and deformation of the electrode.
[0009] In a specific possible implementation scheme, during die cutting, positive R angles and negative R angles are processed at the four corners of the intermediate body, and the positive R angle and the negative R angle are connected to form an S angle.
[0010] By adopting the above technical solution, the positive or negative electrode sheet with an S-angle position is designed. Compared with the single R-angle design, the misalignment rate between two adjacent layers of electrode sheets can be increased after die-cutting, thereby reducing the risk of grabbing multiple sheets at one time due to electrostatic adsorption when the lamination equipment grabs the electrode sheets through vacuum adsorption, and at the same time, the angular strength of the electrode sheet corners can be improved.
[0011] In a specific feasible implementation, after hot pressing and shaping are completed, a porous insulating plate is added to the top of the battery cell body, and the porous insulating plate is located between the battery cell body and the horizontal section of the current collector strip.
[0012] By adopting the above technical solution, the designed porous insulating plate can avoid the risk of short circuit after the pole column on the battery cover is connected to the pole piece.
[0013] In a specific feasible implementation, before welding the vertical section of the current collector strip to the pole ears on the battery cell body, the positive pole ears and negative pole ears on the same side of the battery cell body are first flattened respectively to obtain a fully flattened pole ear position parallel to the vertical section of the current collector strip, and then the vertical section of the current collector strip is welded to the fully flattened pole ear position.
[0014] By adopting the above technical solution, before welding the current collector strip to the pole ears, the fully flattened pole ear positions formed by fully flattening multiple pole ears on the same side of the battery cell body can increase the contact area between the current collector strip and the positive pole ear or negative pole ear, effectively increase the current channel, have stronger overcurrent capacity, reduce the battery internal resistance and at the same time reduce the power consumption loss, and ensure that the battery cell has a large current discharge effect and an effective energy release rate.
[0015] In a specific feasible implementation, when welding the current collector strip, first weld the horizontal section of the current collector strip to the pole column on the battery cover to fix it. At this time, the two current collector strips are in an inverted U-shaped open state, and then weld the vertical section of the current collector strip to the pole ears on the battery cell body to fix it.
[0016] By adopting the above technical solution, the designed current collector strip that is first welded to the pole column on the battery cover and then welded to the pole ears is convenient for realizing the welding with the pole ear position.
[0017] In a second aspect, the present application provides a battery cell.
[0018] A battery cell includes: Multiple positive electrode plates, with a positive pole ear formed on one side of the positive electrode plate; Multiple negative electrode plates, with a negative pole ear formed on one side of the negative electrode plate; Multiple separator membranes, which are integrally bent to form two accommodation cavities with opposite opening directions, and the positive electrode plates and negative electrode plates are respectively located in the accommodation cavities to form the battery cell basis. Multiple battery cell bases are stacked to form the battery cell body, and the positive pole ears and negative pole ears in the battery cell body are on opposite sides; Two current collector strips, the vertical section of one current collector strip is connected to the positive pole ear, the vertical section of the other current collector strip is connected to the negative pole ear, and the two current collector strips are arranged in an inverted U-shaped open state.
[0019] By adopting the above technical scheme, the active material powder, binder, conductive agent and solvent are first mixed in a certain order and under certain conditions to form a stable suspension. This process requires strict control of parameters such as stirring speed, temperature, vacuum degree, etc. to ensure the dispersion uniformity and stability of the slurry. Then, the positive electrode (negative electrode) suspension slurry is evenly coated on the aluminum foil (copper foil) surface and then dried to form a film; then, the active material is closely contacted with the current collector by rolling, the moving distance of the electrons is reduced, the thickness of the pole piece is reduced, the filling amount is increased, and the internal resistance of the battery is reduced and the conductivity is increased; then, according to the process and the size of the incoming material, a slitting machine is used to cut the film roll into multiple rolls of the same size, and then the roll is cut into intermediates of a specified width, and the intermediates are processed to obtain positive and negative electrode sheets with specified sizes of pole ears and pole ear spacing; the positive electrode sheet, the separator and the negative electrode sheet are stacked in an orderly manner along the thickness direction of the positive electrode sheet, and the positive and negative pole ears on the battery body are on opposite sides, and then The battery body is fixed with two layers of high-temperature insulating tape on the top and bottom of the battery body to obtain the battery body; then the battery body is hot-pressed and shaped to eliminate the wrinkles of the diaphragm to discharge the air inside the battery body, so that the diaphragm and the positive and negative plates are closely attached; the horizontal section of the collector strip is welded and fixed to the battery cover plate pole, and the vertical section of the collector strip is welded and fixed to the pole ear on the battery body; the designed battery cell can achieve the following effects by setting the positive and negative pole ears of the battery body to opposite sides. First, the shape characteristics of the battery cell can be used to avoid the narrow space on the top of the battery body, thereby increasing the original size of the positive and negative pole ears, thereby reducing resistance, reducing heat and improving the charging and discharging efficiency and performance of the battery; secondly, the positive and negative pole ears are drained in different directions, which can make the heat dissipation inside the battery uniform, avoid heat concentration and thus the defect of temperature gradient distribution; finally, it can also avoid the secondary bending of the pole ear position under pressure during the assembly and welding of the battery cover, thereby causing the pole piece to be short-circuited and deformed.
[0020] In a specific possible implementation manner, the four corners of the positive electrode sheet and the negative electrode sheet are processed to obtain positive R angles and negative R angles, and the positive R angles and negative R angles are connected to form an S angle.
[0021] By adopting the above technical solution, the positive or negative electrode sheet with an S-angle position is designed. Compared with the single R-angle design, the misalignment rate between two adjacent layers of electrode sheets can be increased after die-cutting, thereby reducing the risk of grabbing multiple sheets at one time due to electrostatic adsorption when the lamination equipment grabs the electrode sheets through vacuum adsorption, and at the same time, the angular strength of the electrode sheet corners can be improved.
[0022] In a specific possible implementation manner, a porous insulating plate is further included, wherein the porous insulating plate is located between the battery cell body and the horizontal section of the current collecting belt, and the porous insulating plate is connected to the positive electrode sheet and the negative electrode sheet.
[0023] By adopting the above technical solution, the designed porous insulating plate can avoid the risk of short circuit after the pole column on the battery upper cover is connected to the pole piece.
[0024] In a specific feasible embodiment, after multiple positive electrode tabs are flattened, a fully flattened positive electrode tab position is formed, and after multiple negative electrode tabs are flattened, a fully flattened negative electrode tab position is formed, and both the fully flattened positive electrode tab position and the fully flattened negative electrode tab position are arranged parallel to the vertical section of the current collector strip.
[0025] By adopting the above technical solution, before the current collector strip is welded to the pole ear, the fully flattened pole ear positions formed by fully flattening multiple pole ears on the same side of the battery cell main body can increase the contact area between the current collector strip and the positive electrode ear or the negative electrode ear, effectively increase the current channels, have stronger overcurrent capacity, reduce the battery internal resistance while reducing the power consumption loss, and ensure that the battery cell has a large current discharge effect and an effective energy release rate.
[0026] In summary, the present application includes at least one of the following beneficial technical effects: 1. The designed battery cell forming process, by setting the positive electrode ear and the negative electrode ear of the battery cell main body on opposite sides, can achieve the following effects. First, by using the shape characteristics of the battery cell, the narrow space at the top of the battery cell main body can be avoided, thereby increasing the original sizes of the positive electrode ear and the negative electrode ear, further reducing the resistance, reducing heat generation and improving the charge and discharge efficiency and performance of the battery. Second, the positive electrode ear and the negative electrode ear drain in opposite directions, which can make the heat dissipation inside the battery uniform, avoid heat concentration and thus avoid the defect of temperature gradient distribution. Finally, it can also avoid the secondary bending and downward pressure of the pole ear position during the assembly and welding of the battery upper cover, thereby avoiding adverse defects such as pole piece short circuit and deformation due to force.
[0027] 2. The designed battery cell forming process, through the positive electrode sheet or the negative electrode sheet with an S corner position, compared with the single R corner design, can increase the misalignment rate between adjacent two layers of pole sheets after die cutting, and further reduce the risk of electrostatic adsorption causing multiple sheets to be grabbed at one time when the pole sheets are grabbed by vacuum adsorption in the laminating equipment, and at the same time, can also improve the corner strength of the pole sheet corner position.
[0028] 3. The designed battery cell forming process, before the current collector strip is welded to the pole ear, the fully flattened pole ear positions formed by fully flattening multiple pole ears on the same side of the battery cell main body can increase the contact area between the current collector strip and the positive electrode ear or the negative electrode ear, effectively increase the current channels, have stronger overcurrent capacity, reduce the battery internal resistance while reducing the power consumption loss, and ensure that the battery cell has a large current discharge effect and an effective energy release rate. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Figure 1 It is a schematic structural diagram of the positive electrode sheet in the battery cell forming process of the embodiment of the present application.
[0030] Figure 2 It is a schematic structural diagram of the negative electrode sheet in the cell forming process of the embodiment of the present application.
[0031] Figure 3 It is a schematic diagram of the relative positions of the positive electrode sheet, the separator, and the negative electrode sheet.
[0032] Figure 4 It is a cross-sectional view after the cell body, the current collector strip, and the porous insulating plate of the embodiment of the present application are assembled.
[0033] Figure 5 It is Figure 4 The enlarged view of part A in
[0034] Explanation of reference numerals: 1, positive electrode sheet; 11, positive electrode tab; 2, negative electrode sheet; 21, negative electrode tab; 3, separator; 31, accommodation cavity; 4, cell body; 5, current collector strip; 6, S corner position; 7, porous insulating plate. Detailed implementation manners
[0035] The following further elaborates on the present application in conjunction with the attached Figures 1-5 drawings.
[0036] The embodiment of the present application discloses a cell forming process and a cell.
[0037] In the first aspect, the embodiment of the present application discloses a cell forming process.
[0038] Referring to Figures 1 to 5 , a cell forming process includes: S1: Preparation of rolled materials; S2: Sheet making and die cutting, cutting the rolled materials into intermediates with a specified width, and processing the intermediates to obtain a positive electrode sheet 1 and a negative electrode sheet 2 with specified dimensions of tabs and tab spacings; S3: Stacking, orderly stacking along the thickness direction of the positive electrode sheet 1 in the order of the positive electrode sheet 1, the separator 3, and the negative electrode sheet 2, and making the positive electrode tab 11 and the negative electrode tab 21 on the cell body 4 on opposite sides; S4: Fixing with adhesive tape, using high-temperature insulating adhesive tape to fix the top and bottom of the cell body 4 with two layers of adhesive tape each to obtain the cell body 4; S5: Hot pressing and shaping, performing hot pressing and shaping on the cell body 4 to eliminate the wrinkles of the separator 3 to discharge the air inside the cell body 4, and making the separator 3 closely adhere to the positive electrode sheet 1 and the negative electrode sheet 2; S6: Welding of the current collector strip 5, welding and fixing the horizontal section of the current collector strip 5 to the pole column of the battery cover plate, and welding and fixing the vertical section of the current collector strip 5 to the tab on the cell body 4.
[0039] The designed battery cell forming process can achieve the following effects by setting the positive ear 11 and the negative ear 21 of the battery cell body 4 on opposite sides. First, the shape characteristics of the battery cell can be utilized to avoid the narrow space on the top of the battery cell body 4, thereby increasing the original size of the positive ear 11 and the negative ear 21, thereby reducing resistance, reducing heat generation and improving the charging and discharging efficiency and performance of the battery. Secondly, the positive ear 11 and the negative ear 21 drain current in different directions, which can make the heat dissipation inside the battery uniform and avoid heat concentration and the defect of temperature gradient distribution. Finally, it can also avoid the secondary bending of the ear position and the downward pressure when assembling and welding the battery cover, which will cause defects such as short circuit and deformation of the pole piece.
[0040] Specifically, step S1: coil material preparation includes: S11: Slurrying: The process of mixing active material powder, binder, conductive agent and solvent in a certain order and under certain conditions to form a stable suspension. This process requires strict control of parameters such as stirring speed, temperature, vacuum degree, etc. to ensure the dispersion uniformity and stability of the slurry; S12: Coating: Evenly coat the positive electrode (negative electrode) suspension slurry on the aluminum foil (copper foil) and then dry it to form a film; the coating quality has an important impact on the consistency, safety and life cycle of the finished battery; S13: Rolling: Rolling is used to make the active material and the current collector in close contact, reduce the moving distance of electrons, reduce the thickness of the pole piece, increase the filling amount, and at the same time reduce the internal resistance of the battery and improve the conductivity; S14: Slitting: According to the process and the size of the incoming material, the film roll is cut into multiple rolls of the same size using a slitting machine.
[0041] Furthermore, in step S2, during die-cutting, positive R angles and negative R angles are processed at the four corners of the intermediate, and the positive R angle and the negative R angle are connected to form an S angle position 6; through the positive electrode sheet 1 or the negative electrode sheet 2 having the S angle position 6, compared with the single R angle design, the misalignment rate between the two adjacent layers of electrode sheets can be increased after die-cutting, and then when the lamination equipment grabs the electrode sheet through vacuum adsorption, the risk of grabbing multiple sheets at one time due to electrostatic adsorption is reduced, and the angle strength of the electrode sheet corner can also be improved.
[0042] Furthermore, in step S5, after the hot pressing and shaping is completed, a porous insulating plate 7 is added to the top of the battery cell body 4, and the porous insulating plate 7 is located between the battery cell body 4 and the horizontal section of the current collecting belt 5; the porous insulating plate 7 can avoid the risk of short circuit after the pole on the battery cover is connected to the pole piece.
[0043] Specifically, in step S6, before welding the vertical section of the current collector strip 5 to the tabs on the battery cell body 4, the positive tab 11 and the negative tab 21 on the same side of the battery cell body 4 are first flattened to obtain a fully flattened tab position parallel to the vertical section of the current collector strip 5, and then the vertical section of the current collector strip 5 is welded to the fully flattened tab position; before welding the current collector strip 5 to the tabs, the fully flattened tab positions formed by fully flattening multiple tabs on the same side of the battery cell body 4 can increase the contact area between the current collector strip 5 and the positive tab 11 or the negative tab 21, effectively increasing the current channel, having a stronger overcurrent capacity, reducing the battery internal resistance while reducing the power consumption loss, and ensuring that the battery cell has a large current discharge effect and an effective energy release rate.
[0044] Further, in step S6, when welding the current collector strip 5, first weld the horizontal section of the current collector strip 5 to the pole column on the battery cover to fix it. At this time, the two current collector strips 5 are in an inverted U-shaped opening state, and then weld the vertical section of the current collector strip 5 to the tabs on the battery cell body 4; the current collector strip 5 that is first welded to the upper pole column on the battery cover and then to the tabs facilitates the welding to the tab position.
[0045] The implementation principle of a battery core forming process in the embodiment of the present application is: first, the active material powder, binder, conductive agent, etc. and solvent are mixed uniformly in a certain order and under certain conditions to form a stable suspension. This process requires strict control of parameters such as stirring speed, temperature, vacuum degree, etc. to ensure the dispersion uniformity and stability of the slurry. Then, the positive electrode (negative electrode) suspension slurry is evenly coated on the aluminum foil (copper foil) surface, and then dried to form a film; then, the active material is closely contacted with the current collector by rolling, thereby reducing the moving distance of the electrons and reducing the The thickness of the electrode sheet is increased, the filling amount is increased, and the internal resistance of the battery is reduced to increase the conductivity; then, according to the process and the size of the incoming material, the film roll is cut into multiple rolls of the same size using a slitting machine, and then the roll is cut into intermediates of specified widths, and the intermediates are processed to obtain positive electrode sheets 1 and negative electrode sheets 2 with specified sizes of tabs and tab spacing; the positive electrode sheet 1, the separator 3 and the negative electrode sheet 2 are stacked in order along the thickness direction of the positive electrode sheet 1, and the positive tab 11 and the negative tab 21 on the battery body 4 are located on opposite sides; then The battery body 4 is fixed with two layers of high-temperature insulating tape on the top and bottom respectively to obtain the battery body 4, and then the battery body 4 is hot-pressed and shaped to eliminate the wrinkles of the diaphragm 3 to discharge the air inside the battery body 4, so that the diaphragm 3 and the positive electrode sheet 1 and the negative electrode sheet 2 are closely attached; the horizontal section of the collector belt 5 is welded and fixed to the battery cover plate pole, and the vertical section of the collector belt 5 is welded and fixed to the pole ear on the battery body 4; by setting the positive pole ear 11 and the negative pole ear 21 of the battery body 4 on opposite sides, the following effects can be achieved. First, The shape characteristics of the battery cell can be utilized to avoid the narrow space on the top of the battery cell body 4, thereby increasing the original size of the positive ear 11 and the negative ear 21, thereby reducing resistance, reducing heat and improving the charging and discharging efficiency and performance of the battery. Secondly, the positive ear 11 and the negative ear 21 drain current in different directions, which can make the heat inside the battery dissipate evenly and avoid heat concentration and the defect of temperature gradient distribution. Finally, it can also avoid the secondary bending of the ear position and the downward pressure when assembling and welding the battery cover, which may cause defects such as short circuit and deformation of the pole piece.
[0046] In a second aspect, an embodiment of the present application discloses a battery cell.
[0047] Reference Figures 1 to 3, a battery cell, prepared by using the battery cell forming process disclosed in the first aspect of the embodiments of the present application, includes a positive electrode sheet 1, a negative electrode sheet 2, and a separator 3. The numbers of the positive electrode sheet 1, the negative electrode sheet 2, and the separator 3 are all multiple. A positive electrode tab 11 is integrally formed on one side of the positive electrode sheet 1, and a negative electrode tab 21 is integrally formed on one side of the negative electrode sheet 2. After the separator 3 is integrally formed, two accommodation cavities 31 are formed. The opening directions of the two accommodation cavities 31 are opposite. The positive electrode sheet 1 and the negative electrode sheet 2 are respectively located in the two accommodation cavities 31. At this time, the positive electrode sheet 1, the separator 3, and the negative electrode sheet 2 form the battery cell base. Multiple battery cell bases are tightly stacked along the thickness direction of the positive electrode sheet 1 or the negative electrode sheet 2 to form the battery cell body 4, and the positive electrode tab 11 and the negative electrode tab 21 are respectively located on opposite sides of the battery cell body 4 and are adjacent to the electrode posts on the battery cover.
[0048] Referring to Figure 4 and Figure 5 , in order to achieve the electrical connection between the positive electrode tab 11 and the negative electrode tab 21 and the electrode posts on the battery cover, the battery cell further includes two current collector strips 5. The current collector strips 5 are arranged in an L shape, and the corners of the current collector strips 5 are rounded to increase the utilization rate of the internal space of the battery. The vertical section of one current collector strip 5 is welded to the positive electrode tab 11, and the vertical section of the other current collector strip 5 is welded to the negative electrode tab 21. The vertical sections of the two current collector strips 5 are arranged parallel to each other, and the two current collector strips 5 are in an inverted U-shaped opening.
[0049] Referring to Figure 4 and Figure 5 , at the four corners of the positive electrode sheet 1 and the negative electrode sheet 2, by controlling the shape of the cutting tool during die cutting, positive R corners and reverse R corners are processed at the four corners of the positive electrode sheet 1 and the negative electrode sheet 2, and an S corner position 6 is formed after the smooth connection of the positive R corners and the reverse R corners. In this embodiment, the positive R corner is the one with the center of the chamfer on the electrode sheet, and the reverse R corner is the one with the center of the chamfer outside the electrode sheet; in the present application, the diameters of the positive R corner and the reverse R corner can be the same or different. In this embodiment, the diameters of the positive R corner and the reverse R corner are the same.
[0050] Referring to Figure 4 and Figure 5 , further, the battery cell further includes a porous insulating plate 7. The porous insulating plate 7 is located between the battery cell body 4 and the horizontal section of the current collector strip 5, and the porous insulating plate 7 is connected to the positive electrode sheet 1 and the negative electrode sheet 2; the porous insulating plate 7 can separate the electrode posts on the battery cover from the positive electrode sheet 1 and the negative electrode sheet 2, thereby avoiding the risk of short circuit when the electrode posts on the battery cover are connected to the electrode sheets.
[0051] Referring to Figure 4 and Figure 5, Further, after the multiple positive electrode tabs 11 are flattened, a fully flattened positive electrode tab 11 position is formed. At this time, the multiple positive electrode tabs 11 are in a parallel state. After the multiple negative electrode tabs 21 are flattened, a fully flattened negative electrode tab 21 position is formed. At this time, the multiple negative electrode tabs 21 are in a parallel state, and both the fully flattened positive electrode tab 11 position and the fully flattened negative electrode tab 21 position are arranged parallel to the vertical section of the current collector strip 5, so as to increase the contact area between the electrode tab position and the current collector strip 5. Before welding the current collector strip 5 and the electrode tab, the multiple electrode tabs on the same side of the battery cell main body 4 are formed into a fully flattened electrode tab position through full flattening treatment, which can increase the contact area between the current collector strip 5 and the positive electrode tab 11 or the negative electrode tab 21, effectively increase the current channel, have a stronger overcurrent capacity, reduce the battery internal resistance and at the same time reduce the power consumption loss, and ensure that the battery cell has a large current discharge effect and an effective energy release rate.
[0052] The above are all the preferred embodiments of the present application, and the protection scope of the present application is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application shall be covered within the protection scope of the present application.
Claims
1. A battery core forming process, characterized in that: include: Coil preparation; Sheeting and die-cutting, slitting the coil into intermediates of specified width, and processing the intermediates to obtain positive electrode sheets (1) and negative electrode sheets (2) with tabs of specified sizes and tab spacing; The stacking is carried out in an orderly manner along the thickness direction of the positive electrode sheet (1) in the order of the positive electrode sheet (1), the separator (3) and the negative electrode sheet (2), and the positive electrode ear (11) and the negative electrode ear (21) on the battery cell body (4) are located on opposite sides; Adhesive tape fixing, using insulating adhesive tape to fix the top and bottom of the battery body (4) to obtain the battery body (4); Hot pressing and shaping, hot pressing and shaping the battery cell body (4), eliminating wrinkles on the diaphragm (3) to discharge air inside the battery cell body (4), and making the diaphragm (3) and the positive electrode sheet (1) and the negative electrode sheet (2) closely adhere to each other; The current collecting belt (5) is welded, the horizontal section of the current collecting belt (5) is welded and fixed to the battery cover plate pole, and the vertical section of the current collecting belt (5) is welded and fixed to the pole lug on the battery cell body (4).
2. The battery core forming process according to claim 1, characterized in that: During die cutting, positive R angle and negative R angle are processed at the four corners of the intermediate body, and the positive R angle and negative R angle are connected to form an S angle position (6).
3. The battery core forming process according to claim 1, characterized in that: After the hot pressing shaping is completed, a porous insulating plate (7) is added to the top of the battery cell body (4), and the porous insulating plate (7) is located between the battery cell body (4) and the horizontal section of the current collecting belt (5).
4. The battery core forming process according to claim 3, characterized in that: Before the vertical section of the current collecting belt (5) is welded to the pole ear on the battery cell body (4), the positive pole ear (11) and the negative pole ear (21) on the same side of the battery cell body (4) are respectively flattened to obtain a fully flattened pole ear position parallel to the vertical section of the current collecting belt (5), and then the vertical section of the current collecting belt (5) is welded to the fully flattened pole ear position.
5. The battery core forming process according to any one of claims 3-4, characterized in that: When welding the current collecting strip (5), the horizontal section of the current collecting strip (5) is first welded and fixed to the battery upper cover pole, at which time the two current collecting strips (5) are in an inverted U-shaped opening, and then the vertical section of the current collecting strip (5) is welded and fixed to the pole ear on the battery body (4).
6. A battery cell, characterized in that: include: A plurality of positive electrode sheets (1), each positive electrode sheet (1) having a positive electrode ear (11) formed on one side thereof; A plurality of negative electrode sheets (2), each negative electrode sheet (2) having a negative electrode ear (21) formed on one side thereof; A plurality of diaphragms (3), wherein the diaphragms (3) are integrally bent to form two accommodating cavities (31) with opposite opening directions, and the positive electrode sheet (1) and the negative electrode sheet (2) are respectively located in the accommodating cavities (31) and form a battery cell foundation, and the plurality of battery cell foundations are stacked to form a battery cell body (4), and the positive electrode ear (11) and the negative electrode ear (21) in the battery cell body (4) are located on opposite sides; Two current collecting strips (5), a vertical section of one current collecting strip (5) is connected to the positive electrode lug (11), and a vertical section of the other current collecting strip (5) is connected to the negative electrode lug (21), and the two current collecting strips (5) are arranged in an inverted U-shaped opening.
7. The battery cell according to claim 6, characterized in that: The four corners of the positive electrode sheet (1) and the negative electrode sheet (2) are processed to obtain positive R angles and negative R angles, and the positive R angles and negative R angles are connected to form an S angle position (6).
8. The battery cell according to claim 6, characterized in that: It also includes a porous insulating plate (7), which is located between the battery cell body (4) and the horizontal section of the current collecting belt (5), and the porous insulating plate (7) is connected to the positive electrode sheet (1) and the negative electrode sheet (2).
9. The battery cell according to claim 6, characterized in that: After the plurality of positive electrode ears (11) are flattened, a fully flattened positive electrode ear (11) position is formed; after the plurality of negative electrode ears (21) are flattened, a fully flattened negative electrode ear (21) position is formed; and the fully flattened positive electrode ear (11) position and the fully flattened negative electrode ear (21) position are both arranged parallel to the vertical section of the current collecting belt (5).