A lithium ion battery baking device
By using a double-layer pressing device to constrain, compress, and bake the stacked cores, and monitoring the process with temperature and pressure sensors, the problem of electrode wrinkling caused by stacked core deformation was solved, thus improving the long-term cycle performance and process efficiency of lithium-ion batteries.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI XUANYI NEW ENERGY DEV CO LTD
- Filing Date
- 2025-06-18
- Publication Date
- 2026-07-24
AI Technical Summary
During the thermal composite stacking process, the electrode wrinkling problem caused by the deformation of the stacked core seriously affects the long-term cycle performance of lithium-ion batteries, and existing technologies are difficult to solve effectively.
A double-layer pressing device is used, which integrates baking components and a clamping device to constrain and press the stacked cores during baking. Temperature and pressure sensors are used to monitor the process. Heating and pressurizing release the internal stress of the electrode and diaphragm, avoiding the need for additional processes.
It effectively improves the problem of core deformation after thermal recombination, while maintaining process efficiency, without adding extra steps, and improving the long-term cycle performance of lithium-ion batteries.
Smart Images
Figure CN224554367U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of lithium-ion battery preparation technology, and in particular to a lithium-ion battery baking device. Background Technology
[0002] With the rapid development of the new energy industry, lithium-ion batteries have increasingly higher requirements in terms of energy density and long cycle life. In order to cope with this trend, the application of stacking technology has become more widespread in recent years, especially the application of thermal composite stacking technology, which has solved the problem of low efficiency of stacking technology.
[0003] Hot-pressed composite stacking uses a double-sided coated separator. Cut electrodes are placed on both sides of the separator, and the separator and positive and negative electrodes are heated. The heated electrodes and the adhesive-coated separator are then rolled together to form a composite unit. Changes in the separator's state after heating and rolling significantly affect battery performance, especially long-term cycle performance. Among these challenges, electrode wrinkling caused by deformation after hot pressing is a critical technical problem that urgently needs to be solved. Utility Model Content
[0004] To address the problems existing in the prior art, this utility model provides a lithium-ion battery baking device, comprising:
[0005] A double-layered pressure plate, wherein a stacked core is placed between the double-layered pressure plates, and a baking component is integrated in the double-layered pressure plate;
[0006] A restraining device extends through the double-layer pressure plate and is used to press the double-layer pressure plate together.
[0007] Preferably, each layer of the double-layer pressure plate integrates a temperature sensor.
[0008] Preferably, each layer of the double-layer pressure plate integrates a pressure sensor.
[0009] Preferably, the restraint device includes:
[0010] Multiple sliding rods, each of which simultaneously passes through each layer of the double-layer pressure plate;
[0011] A pressurizing device is provided at the end of each of the slide bars.
[0012] Preferably, the core is a multi-layered stack of sheets stacked in a "Z" shape.
[0013] Preferably, each of the laminated layers includes two layers of coated separators, with a negative electrode sheet bonded between the two coated separators, and a positive electrode sheet bonded to the outside of the coated separators.
[0014] Preferably, the positive electrode sheets of the stacked sheets of adjacent layers are alternately bonded to the outside of the coated separators of different layers.
[0015] Preferably, the positive electrode includes a binder, a conductive agent, an additive, an active material, and a current collector, wherein the active material includes at least one of lithium iron phosphate, lithium cobalt oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium titanate, lithium-rich material, and 5V spinel.
[0016] Preferably, the negative electrode sheet includes a thickener, a binder, a conductive agent, an additive, an active material, and a current collector, wherein the active material includes at least one of graphite, SiO / C, and Si / C.
[0017] Preferably, the coated diaphragm includes a base film and an adhesive layer on the surface of the base film;
[0018] The base film includes one of polypropylene, polyethylene, polypropylene / polyethylene / polypropylene, polyamide, or polyimide; the adhesive layer includes an oil-based adhesive layer or a water-based adhesive layer.
[0019] The above technical solution has the following advantages or beneficial effects:
[0020] This utility model provides a lithium-ion battery baking device that constrains and presses the stacked cores during baking. Due to the pressure plate raising the temperature of the stacked cores, combined with the pressure applied to the stacked cores, the binders in the positive and negative electrode sheets and the adhesive separator diffuse and move more violently. This releases the internal stress of the electrode sheets and separator, thereby improving the problem of electrode wrinkles caused by the deformation of the stacked cores after thermal bonding. At the same time, the pressure applied during baking does not add any extra steps, thus ensuring process efficiency. Attached Figure Description
[0021] Figure 1 A schematic diagram of the structure of a lithium-ion battery baking device is shown in a preferred embodiment of this utility model.
[0022] Figure 2 This is a schematic diagram of the process of manufacturing a stacked core for a lithium-ion battery thermal composite stack, which is a preferred embodiment of the present invention. Detailed Implementation
[0023] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment; other embodiments that conform to the spirit of the present invention may also fall within its scope.
[0024] In a preferred embodiment of this utility model, based on the above-mentioned problems existing in the prior art, a lithium-ion battery baking device is now provided, such as... Figure 1 As shown, it includes:
[0025] Double-layer pressure plate 1, stacked core 2 is placed between the double-layer pressure plate 1, and baking component 3 is integrated in the double-layer pressure plate 1;
[0026] The restraint device 4 penetrates the double-layer pressure plate 1 and is used to press the double-layer pressure plate 1 tightly.
[0027] Specifically, the thermal lamination stacking machine heats the coated diaphragm, negative electrode sheet, and positive electrode sheet respectively. After passing through the lamination roller, the negative electrode is bonded to the inner side of the two diaphragm layers, and the heated positive electrode is bonded to the outer side of the two diaphragm layers. Finally, each small composite unit sheet is stacked in a "Z" shape to form a core. Due to the pressure of the lamination roller, the stress of the core cannot be released, resulting in problems such as "U"-shaped electrodes and wrinkles.
[0028] In this embodiment, the stacked core is constrained and baked. Since the baking component 3 (such as heating wire, heating rod, etc. embedded in the pressure plate 1) is integrated into the pressure plate 1, the temperature of the stacked core 2 is raised. Combined with the pressure applied to the stacked core by the confinement device 4, the adhesive in the positive and negative electrode sheets and the adhesive in the coated diaphragm diffuse and move more violently. This allows the internal stress of the electrode sheets and diaphragm to be released, thereby improving the problem of stacked core deformation after thermal bonding. At the same time, the pressure applied during baking does not add any extra steps, thus ensuring process efficiency.
[0029] In a preferred embodiment of this invention, each layer of the double-layer pressure plate 1 integrates a temperature sensor.
[0030] In a preferred embodiment of this invention, each layer of the double-layer pressure plate 1 integrates a pressure sensor.
[0031] Specifically, the pressure plate also integrates temperature and pressure sensors, which are used to monitor the temperature during the baking process and the pressure of the pressure plate on the stacked cores, respectively, to help determine whether the current process is normal.
[0032] In a preferred embodiment of this invention, the restraining device 4 includes:
[0033] Multiple sliding rods 41, each sliding rod 41 simultaneously passes through each layer of the double-layer pressure plate 1;
[0034] A pressurizing device 42 is provided at the end of each slide rod 41.
[0035] Specifically, such as Figure 1 As shown, the restraint device 4 includes multiple sliding rods 41. Figure 1 This is a side view, so only two sliding rods 41 are visible. The sliding rods 41 pass through each layer of pressure plates, allowing the pressure plates to slide freely on the rods and change the spacing between them. A core stack is placed between the two layers of pressure plates 1, and the two layers of pressure plates are pressed together by a pressurizing device 42 to achieve the pressing of the core stack. The pressurizing device 42 can be a hydraulic device or other lifting mechanism, using a slider connected to the sliding rod to press and tighten the pressure plates.
[0036] In a preferred embodiment of this invention, the core is a multi-layer stacked core formed by stacking multiple layers of sheets in a "Z" shape.
[0037] In a preferred embodiment of the present invention, each laminate includes two layers of coated separators, a negative electrode sheet is bonded between the two coated separators, and a positive electrode sheet is bonded to the outside of the coated separators.
[0038] In a preferred embodiment of this invention, the positive electrode sheets of adjacent laminated layers are alternately bonded to the outer sides of the coated separators of different layers, such as... Figure 2 As shown, each layer of lamination is a composite unit before the core is stacked, and adjacent composite unit stacks are stacked to form adjacent layers.
[0039] In a preferred embodiment of this invention, the positive electrode sheet includes a binder, a conductive agent, an additive, an active material, and a current collector, wherein the active material includes at least one of lithium iron phosphate, lithium cobalt oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium titanate, lithium-rich material, and 5V spinel.
[0040] In a preferred embodiment of this invention, the negative electrode sheet includes a thickener, a binder, a conductive agent, an additive, an active material, and a current collector, wherein the active material includes at least one of graphite, SiO / C, and Si / C.
[0041] In a preferred embodiment of this invention, the adhesive-coated diaphragm includes a base film and an adhesive layer on the surface of the base film;
[0042] The base film includes one of polypropylene, polyethylene, polypropylene / polyethylene / polypropylene, polyamide or polyimide; the adhesive layer includes an oil-based adhesive layer or a water-based adhesive layer.
[0043] Specifically, in this utility model, the complete manufacturing process of the lithium-ion battery, from stacking to baking, is as follows:
[0044] S1. The coated separator, negative electrode, and positive electrode are heated separately, and then pressed by rollers to bond the negative electrode to the inner side of the two separator layers, while the heated positive electrode is bonded to the outer side of the two separator layers. Finally, each small unit is stacked in a "Z" shape to form a core. A schematic diagram of the core is shown below. Figure 2 As shown;
[0045] Specifically, thermal lamination involves separating positive and negative electrode sheets of a specified width and length with a coated separator, and continuously stacking them according to a positive electrode sheet / coated separator / negative electrode sheet structure to form a core. The specific lamination method is well-known in the art and will not be described in detail here.
[0046] Optionally, the aforementioned positive electrode sheet may include, for example, a binder, a conductive agent, an additive, an active material, and a current collector, wherein the active material may be at least one of lithium iron phosphate (LFP), lithium cobalt oxide (LCO), lithium nickel cobalt manganese oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), lithium titanate (LTO), lithium-rich materials, and 5V spinel.
[0047] Optionally, the aforementioned negative electrode sheet may include, for example, a thickener, a binder, a conductive agent, an additive, an active material, and a current collector, wherein the active material may be any one or a mixture of at least two of graphite, SiO / C, and Si / C.
[0048] Optionally, the base film of the coated diaphragm may include, for example, polypropylene (PP), polyethylene (PE), polypropylene / polyethylene / polypropylene (PP / PE / PP), polyamide (PA), or polyimide (PI); the adhesive layer of the coated diaphragm may include, for example, an oil-based adhesive layer or a water-based adhesive layer; a ceramic layer for improving safety performance may be provided between the adhesive layer and the base film, or the ceramic layer may not be provided.
[0049] S2. The stacked cores output from the thermal composite stacking machine are constrained and baked, and the baked stacked cores are subjected to preset process combinations to manufacture lithium-ion batteries; wherein, the baking process applies pressure to the stacked cores while baking them.
[0050] The preset process combination includes a welding process, an assembly process, a electrolyte injection process, a high-temperature wetting process, and a formation process. The baking process removes moisture from the battery core by heating. The welding process involves ultrasonically or laser welding the battery core and the tabs together. The assembly process involves welding the battery core with tabs to the cover plate, then encapsulating it in an aluminum shell for peripheral welding. The electrolyte injection process injects electrolyte into the baked battery. The high-temperature wetting process ensures the electrolyte completely wets the positive and negative electrodes and the coated separator. The formation process involves the battery undergoing its first charge to activate it. In practical applications, the processes in the preset process combination can be added or removed according to specific needs; this embodiment of the invention does not impose any particular limitations on this.
[0051] In step S2 above, when the coated diaphragm is an oil-based diaphragm, the pressure used in the baking process is greater than or equal to 0.1 MPa ± 0.05 MPa and less than or equal to 0.6 MPa ± 0.05 MPa per unit area.
[0052] When the coated diaphragm is an aqueous diaphragm, the temperature control for pressurizing and heating the stacked core is greater than or equal to 80℃±5℃ and less than or equal to 95℃±5℃, and the pressure per unit area is greater than or equal to 0.3MPa±0.05MPa and less than or equal to 0.8MPa±0.05MPa.
[0053] The baking process takes a time of 10 hours or more and 24 hours or less, with 12 hours being preferred.
[0054] Because the baking process raises the temperature of the stacked core, and combined with the pressure applied to the stacked core, the binders in the positive and negative electrodes and the adhesive diaphragm diffuse and move more violently. This releases the internal stress of the electrodes and diaphragms, thereby improving the problem of core deformation after thermal bonding. At the same time, applying pressure during baking does not add any extra steps, thus ensuring process efficiency.
[0055] The above are merely preferred embodiments of the present utility model and are not intended to limit the implementation methods and protection scope of the present utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made using the content of this specification and illustrations should be included within the protection scope of the present utility model.
Claims
1. A lithium-ion battery baking device, characterized in that, include: A double-layered pressure plate, wherein a stacked core is placed between the double-layered pressure plates, and a baking component is integrated in the double-layered pressure plate; A restraining device extends through the double-layer pressure plate and is used to press the double-layer pressure plate together.
2. The lithium-ion battery baking apparatus according to claim 1, characterized in that, Each layer of the double-layer pressure plate integrates a temperature sensor.
3. The lithium-ion battery baking apparatus according to claim 1, characterized in that, Each layer of the double-layer pressure plate integrates a pressure sensor.
4. The lithium-ion battery baking apparatus according to claim 1, characterized in that, The restraint device includes: Multiple sliding rods, each of which simultaneously passes through each layer of the double-layer pressure plate; A pressurizing device is provided at the end of each of the slide bars.
5. The lithium-ion battery baking apparatus according to claim 1, characterized in that, The core is formed by stacking multiple layers of sheets in a "Z" shape.
6. The lithium-ion battery baking apparatus according to claim 5, characterized in that, Each of the stacked layers includes two layers of coated separators, with a negative electrode sheet bonded between the two coated separators, and a positive electrode sheet bonded to the outside of the coated separators.
7. The lithium-ion battery baking apparatus according to claim 6, characterized in that, The positive electrode sheets of the stacked sheets of adjacent layers are alternately bonded to the outside of the coated separators of different layers.
8. The lithium-ion battery baking apparatus according to claim 6, characterized in that, The positive electrode includes a binder, a conductive agent, an additive, an active material, and a current collector, wherein the active material includes at least one of lithium iron phosphate, lithium cobalt oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium titanate, lithium-rich material, and 5V spinel.
9. The lithium-ion battery baking apparatus according to claim 6, characterized in that, The negative electrode sheet includes a thickener, a binder, a conductive agent, an additive, an active material, and a current collector, wherein the active material includes at least one of graphite, SiO / C, and Si / C.
10. The lithium-ion battery baking apparatus according to claim 6, characterized in that, The coated diaphragm includes a base membrane and an adhesive layer on the surface of the base membrane; The base film includes one of polypropylene, polyethylene, polypropylene / polyethylene / polypropylene, polyamide, or polyimide; the adhesive layer includes an oil-based adhesive layer or a water-based adhesive layer.