Battery lamination process and battery
By using a stacking process involving thermal bonding of the negative electrode roll with the separator and Z-shaped folding, the problems of low battery stacking efficiency and low negative electrode bonding strength were solved, achieving efficient and stable battery manufacturing and reducing production costs.
Patent Information
- Application Number
- CN202511259843.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-04
- Publication Date
- 2025-12-12
AI Technical Summary
Existing battery stacking technology is inefficient, has low bonding strength between the negative electrode and the separator, and involves a complicated stacking process, which increases manufacturing costs and affects battery stability and lifespan.
The positive electrode roll is prepared by thermally bonding the negative electrode roll with the separator and then processed into a positive electrode sheet. The negative electrode composite roll is folded in a Z-shape and the positive electrode sheet is inserted between the layers, which eliminates the need for picking up the negative electrode sheet and improves the stacking efficiency. Before folding, holes are punched at the crease to release stress, and adhesive layers such as polyvinylidene fluoride are used to enhance adhesion.
It improves the stacking efficiency, enhances the adhesion between the negative electrode and the separator, reduces separator displacement and detachment, improves battery stability and safety, and reduces production costs.
Smart Images
Figure CN121123347A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of battery technology, and more specifically, relates to a battery stacking process and a battery. Background Technology
[0002] Currently, battery stacking technology still has some shortcomings in terms of efficiency and cost. In traditional processes, both the positive and negative electrodes need to be cut into individual pieces, and the positive and negative electrode pieces need to be picked up and moved simultaneously during the stacking process, resulting in slow manufacturing speed and cumbersome process.
[0003] Furthermore, the bonding strength between the negative electrode and the separator needs improvement, which affects the stability and lifespan of the entire battery module. Current technologies also rely heavily on traditional methods for the adsorption mechanism during stacking, failing to fully utilize innovations in adsorption technology.
[0004] In addition, the thermal bonding of the negative electrode and the separator during the manufacturing process of battery components often involves multiple steps, which increases manufacturing costs.
[0005] These technological shortcomings have led to challenges in power battery manufacturing, including low production efficiency, high costs, and difficulty in further improving product performance. Therefore, seeking a more efficient and stable stacking technology, improving the preparation methods of the negative electrode and separator, and optimizing the adsorption mechanism are crucial for enhancing the overall efficiency of power battery manufacturing and reducing production costs. This invention aims to overcome these shortcomings and bring significant technological advancements to the field of power battery manufacturing. Summary of the Invention
[0006] The purpose of this invention is to provide a battery stacking process and a battery that solves the problems of low efficiency and low bonding strength between the negative electrode and the separator in existing stacking processes.
[0007] To achieve the above objectives, firstly, conveniently, the present invention provides a battery stacking process, comprising:
[0008] Prepare positive and negative electrode rolls;
[0009] Both sides of the negative electrode roll are thermally bonded to the separator to obtain a negative composite electrode roll.
[0010] The positive electrode coil is processed into multiple positive electrode sheets;
[0011] The negative electrode composite coil is folded in a Z-shape to form multiple composite layers, and a positive electrode sheet is inserted between the layers of the composite layer.
[0012] Optionally, before rolling the negative electrode composite electrode into a Z-shaped fold, the method further includes: pre-drilling multiple holes at each fold.
[0013] Optionally, the number of holes at each crease is 5 to 10.
[0014] Optionally, the hole is circular.
[0015] Furthermore, the diameter of the hole is 0.5mm-1.2mm.
[0016] Optionally, the hole is a parallelogram.
[0017] Furthermore, the side length of the hole is 0.3-1.0 mm.
[0018] Optionally, before thermally bonding both sides of the negative electrode roll to the separator, the process further includes:
[0019] An adhesive layer is coated on the surface of the diaphragm, and the adhesive layer is composed of one of polyvinylidene fluoride, polymethyl methacrylate, or sodium carboxymethyl cellulose.
[0020] Optionally, the preparation of the positive electrode roll and the negative electrode roll includes:
[0021] Prepare a positive electrode slurry, coat the positive electrode slurry onto a positive electrode current collector to obtain a positive electrode coated roll, and roll the positive electrode coated roll to obtain a positive electrode roll.
[0022] A negative electrode slurry is prepared, and the negative electrode slurry is coated onto a negative electrode current collector to obtain a positive electrode coated roll. The negative electrode coated roll is then rolled and processed with negative electrode tabs to obtain a negative electrode roll.
[0023] In a second aspect, the present invention provides a battery manufactured according to the battery stacking process described in the first aspect.
[0024] The beneficial effects of this invention are as follows: It provides a battery stacking process, comprising: preparing a positive electrode roll and a negative electrode roll; thermally bonding both sides of the negative electrode roll to a separator to obtain a negative composite electrode roll; processing the positive electrode roll into multiple positive electrode sheets; folding the negative composite electrode roll in a Z-shape to form multiple composite layers, and inserting positive electrode sheets between the layers of the composite layers. This battery stacking process only requires processing the positive electrode into positive electrode sheets, eliminating the need to process the negative electrode into negative electrode sheets. The stacking process only requires picking up and moving the positive electrode sheets, eliminating the step of picking up and moving the negative electrode sheets, thus improving stacking efficiency. Furthermore, before the stacking process, the negative electrode and separator have already undergone thermal bonding, resulting in stronger adhesion between the negative electrode and the separator, reducing the possibility of separator displacement or detachment during subsequent processing.
[0025] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description
[0026] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the invention.
[0027] Figure 1 One of the flowcharts of the battery stacking process of the present invention is shown.
[0028] Figure 2 A second flowchart of the battery stacking process of the present invention is shown.
[0029] Explanation of reference numerals in the attached figures:
[0030] 1. Negative electrode roll after roll forming; 2. Negative electrode roll after perforation; 3. Negative electrode roll after tab die cutting; 4. Negative composite electrode roll; 5. Positive electrode sheet. Detailed Implementation
[0031] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
[0032] like Figure 1 and 2 As shown, in a first aspect, the present invention provides a battery stacking process, comprising:
[0033] Prepare positive and negative electrode rolls;
[0034] Both sides of the negative electrode roll are thermally bonded to the separator to obtain negative electrode composite roll 4;
[0035] The positive electrode roll is processed into multiple positive electrode sheets 5;
[0036] The negative electrode composite coil 4 is folded in a Z-shape to form multiple composite layers, and the positive electrode sheet 5 is inserted between the layers of the composite layers.
[0037] Specifically, this battery stacking process only requires processing the positive electrode into a positive electrode sheet 5, without needing to process the negative electrode into a negative electrode sheet. The negative electrode coil and separator are thermally bonded, and the negative electrode composite coil 4 is then stacked with the positive electrode sheet 5 to obtain the stacked battery cell. The stacking process only requires picking up and moving the positive electrode sheet 5, eliminating the step of picking up and moving the negative electrode sheet, thus improving stacking efficiency. Furthermore, before the stacking process, the negative electrode and separator have already undergone thermal bonding, resulting in stronger adhesion between them and reducing the possibility of separator displacement or detachment during subsequent processing.
[0038] Optionally, before folding the negative electrode composite coil 4 into a Z-shape, the method further includes pre-drilling multiple holes at each crease.
[0039] Specifically, pre-drilling holes at the creases can effectively release the stress generated during folding, making it easier to fold and reducing material damage caused by stress concentration.
[0040] Optionally, the number of holes at each crease is 5 to 10.
[0041] Specifically, if there are too many holes, the tape is prone to breakage; if there are too few holes, it is not easy to fold.
[0042] Optionally, the hole is circular.
[0043] Furthermore, the diameter of the hole is 0.5mm-1.2mm.
[0044] Optionally, the hole is a parallelogram.
[0045] Furthermore, the side length of the hole is 0.3-1.0 mm.
[0046] Optionally, both sides of the negative electrode roll are thermally bonded to the diaphragm, wherein the rolling pressure is 2000 kgf to 8000 kgf and the roller temperature is greater than 85°C.
[0047] Specifically, the rolling pressure is 2000 kgf to 8000 kgf, and the roller temperature is greater than 85°C. This ensures stronger adhesion between the negative electrode roll and the separator, reducing the possibility of separator displacement or detachment during subsequent processing, thereby improving the stability and safety of the battery.
[0048] Optionally, before thermally bonding both sides of the negative electrode roll to the separator, the process further includes:
[0049] An adhesive layer is coated on the surface of the diaphragm. The adhesive layer is composed of one of polyvinylidene fluoride, polymethyl methacrylate, or sodium carboxymethyl cellulose. The adhesive layer can be applied to one side or both sides.
[0050] Specifically, the separator coated with adhesive can better bond with the negative electrode roll during the thermal bonding process, reducing battery short circuits or leakage caused by poor adhesion between the separator and the electrode roll, thereby improving battery safety and lifespan.
[0051] Optionally, the preparation of the positive electrode roll and the negative electrode roll includes:
[0052] Prepare a positive electrode slurry, coat the positive electrode slurry onto a positive electrode current collector to obtain a positive electrode coated roll, and roll the positive electrode coated roll to obtain a positive electrode roll.
[0053] A negative electrode slurry is prepared, and the negative electrode slurry is coated onto a negative electrode current collector to obtain a positive electrode coated roll. The negative electrode coated roll is then rolled and processed with negative electrode tabs to obtain a negative electrode roll.
[0054] Furthermore, the positive current collector can be aluminum foil, and the negative current collector can be copper foil.
[0055] Optionally, the preparation of the positive electrode slurry and the negative electrode slurry includes: homogenizing the positive electrode material, conductive agent and binder to obtain the positive electrode slurry; and homogenizing the negative electrode material, conductive agent and binder to obtain the positive electrode slurry.
[0056] In a second aspect, the present invention provides a battery manufactured according to the battery stacking process described in the first aspect.
[0057] Example 1
[0058] like Figure 2 As shown, this embodiment provides a battery stacking process, the steps of which are as follows:
[0059] Step 1: Homogenize the negative electrode material, conductive agent, and binder at a ratio of 96%, 1.5%, and 2.5% respectively to prepare the negative electrode slurry. Homogenize the positive electrode material, conductive agent, and binder at a ratio of 96%, 1.5%, and 2.5% respectively according to the established homogenization process to prepare the positive electrode slurry.
[0060] Step 2: Coat the positive electrode slurry evenly on the aluminum foil with a surface density of 300g / m2, leaving the two sides blank without slurry coating, to obtain the positive electrode coated roll; coat the negative electrode slurry evenly on the copper foil with a surface density of 100g / m2, leaving the two sides blank without slurry coating, to obtain the negative electrode coated roll.
[0061] Step 3: Roll the positive electrode coated roll at a compaction density of 3.4 g / cm3 to obtain the rolled positive electrode roll, and roll the negative electrode coated roll at a compaction density of 1.65 g / cm3 to obtain the rolled negative electrode roll 1;
[0062] Step 4: Punch 5 holes along the width of the negative electrode roll after rolling, punching only in the coated area and not in the blank foil area; punch holes every 100mm along the length of the electrode to prepare the punched negative electrode roll 2; the holes are round and 0.5mm in diameter.
[0063] Step 5: Die-cut the empty foil portion of the punched negative electrode roll 2 to cut out the tab shape. The tab is 20mm wide and 25mm high, thus preparing the negative electrode roll 3 after tab die-cutting.
[0064] Step 6: The diaphragm and the negative electrode roll 3 after the electrode tab is die-cut are thermally composited by hot rolling to prepare the negative electrode composite roll 4; the rolling pressure is 2000 kgf, the roller temperature is 85℃, and the diaphragm is coated with an adhesive layer on one side, the composition of which is polyvinylidene fluoride.
[0065] Step 7: Die-cut the positive electrode roll into single pieces according to the design dimensions of the positive electrode sheet 5. The design dimensions of the positive electrode sheet 5 in the length and width directions are 2mm and 3mm smaller than those of the negative electrode, respectively, to ensure sufficient overhang.
[0066] Step 8: Stack the negative composite electrode roll 4 and the positive electrode sheet 5. During the stacking process, the positive electrode sheet 5 is moved by a chuck and inserted between the layers of the composite stack to obtain the stacked cell.
[0067] Example 2
[0068] like Figure 2 As shown, this embodiment provides a battery stacking process, the steps of which are as follows:
[0069] Step 1: The negative electrode material, conductive agent, and binder are homogenized according to the established homogenization process at a ratio of 95%, 2%, and 3% respectively to prepare the negative electrode slurry. The positive electrode material, conductive agent, and binder are homogenized according to the established homogenization process at a ratio of 95%, 2%, and 3% respectively to prepare the positive electrode slurry.
[0070] Step 2: Coat the positive electrode slurry evenly on the aluminum foil with a surface density of 400g / m2, leaving the two sides blank to obtain the positive electrode coated roll; coat the negative electrode slurry evenly on the copper foil with a surface density of 200g / m2, leaving the two sides blank to obtain the negative electrode coated roll.
[0071] Step 3: Roll the positive electrode coated sheet to a compaction density of 3.5 g / cm3 to obtain the rolled positive electrode roll, and roll the negative electrode coated sheet to a compaction density of 1.7 g / cm3 to obtain the rolled negative electrode roll.
[0072] Step 4: Punch 8 holes along the width of the negative electrode roll after rolling. Punch holes only in the coated area and do not punch holes in the foil in the blank area. Punch holes every 120mm along the length of the electrode to prepare the punched negative electrode roll. The holes are round and 0.7mm in diameter.
[0073] Step 5: Die-cut the empty foil portion of the punched negative electrode roll to cut out the tab shape. The tab is 23mm wide and 30mm high, thus preparing the negative electrode roll 3 after tab die-cutting.
[0074] Step 6: The diaphragm and the negative electrode roll after the tab is die-cut are thermally composited by hot rolling to prepare negative electrode composite roll 4; the rolling pressure is 2500 kgf, the roller temperature is 90℃, and the diaphragm is coated with an adhesive layer on one side, the adhesive layer is composed of polyvinylidene fluoride.
[0075] Step 7: Die-cut the positive electrode roll into single pieces according to the design dimensions of the positive electrode sheet 5. The design dimensions of the positive electrode sheet 5 in the length and width directions are 3mm and 2mm smaller than those of the negative electrode sheet, respectively, to ensure sufficient overhang.
[0076] Step 8: Stack the negative electrode composite coil 4 and the positive electrode sheet 5 together. Use a suction cup to pick up and move the positive electrode sheet 5, and insert the positive electrode sheet 5 between the layers of the composite stack to obtain the stacked cell.
[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
[0078] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.
Claims
1. A battery stacking process, characterized in that, include: Prepare positive and negative electrode rolls; Both sides of the negative electrode roll are thermally bonded to the diaphragm to obtain the negative electrode composite roll (4); The positive electrode roll is processed into multiple positive electrode plates (5); The negative electrode composite coil (4) is folded in a Z-shape to form multiple composite layers, and a positive electrode sheet (5) is inserted between the layers of the composite layers.
2. The battery stacking process according to claim 1, characterized in that, Before folding the negative electrode composite coil (4) into a Z-shape, the method further includes: pre-drilling multiple holes at each crease.
3. The battery stacking process according to claim 2, characterized in that, There are 5 to 10 holes at each crease.
4. The battery stacking process according to claim 2, characterized in that, The hole is circular.
5. The battery stacking process according to claim 4, characterized in that, The diameter of the hole is 0.5mm-1.2mm.
6. The battery stacking process according to claim 2, characterized in that, The hole is a parallelogram.
7. The battery stacking process according to claim 6, characterized in that, The side length of the hole is 0.3-1.0 mm.
8. The battery stacking process according to claim 1, characterized in that, Before thermally bonding both sides of the negative electrode roll to the separator, the process further includes: An adhesive layer is coated on the surface of the diaphragm, and the adhesive layer is composed of one of polyvinylidene fluoride, polymethyl methacrylate, or sodium carboxymethyl cellulose.
9. The battery stacking process according to claim 1, characterized in that, The preparation of the positive and negative electrode rolls includes: Prepare a positive electrode slurry, coat the positive electrode slurry onto a positive electrode current collector to obtain a positive electrode coated roll, and roll the positive electrode coated roll to obtain a positive electrode roll. A negative electrode slurry is prepared, and the negative electrode slurry is coated onto a negative electrode current collector to obtain a positive electrode coated roll. The negative electrode coated roll is then rolled and processed with negative electrode tabs to obtain a negative electrode roll.
10. A battery, characterized in that, The battery is manufactured using the battery stacking process according to any one of claims 1-9.