A hot compounding lamination roll and a lamination machine

Abstract

The utility model provides a kind of thermal composite lamination roll and lamination machine, it is related to the technical field of battery preparation, including arc press roll and the conventional roll of being arranged in the side of arc press roll, heating device is integrated in arc press roll.Affirmative effect is that the arc formed by the surface of roller body of arc press roll offsets deflection deformation under working pressure, and the problem of uneven pressure distribution is solved from the root.This design guarantees the flatness, bonding reliability and air permeability uniformity of pole piece and diaphragm, and finally improves the cycle life and safety of battery.

Description

Technical Field

[0001] This utility model relates to the field of battery cell manufacturing technology, and in particular to a thermal composite stacking roller and stacking machine. 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] Thermally laminated cells utilize 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. After heating and rolling, the uneven deformation of the rollers on the electrodes and separator, and the uneven air permeability of the separator, severely affect battery performance, especially long-term cycle performance. Among these challenges, the uneven distribution of air permeability in the separator after rolling, leading to reduced power, cycle, and fast-charging performance, 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 thermal composite stacking roller, including an arc-shaped pressure roller and a conventional roller disposed on one side of the arc-shaped pressure roller, wherein a heating device is integrated in the arc-shaped pressure roller.

[0005] Preferably, temperature sensors are provided in the arc-shaped pressure roller and the conventional roller.

[0006] Preferably, pressure sensors are provided at both ends of the arc-shaped pressure roller and the conventional roller.

[0007] Preferably, the heating device includes multiple heating tubes, each of which is arranged circumferentially along the central axis of the arc-shaped pressure roller.

[0008] This utility model also provides a stacking machine, including the thermal composite stacking roller as described above, and further including:

[0009] The diaphragm conveying mechanism has an electrode supply mechanism at the starting point of the conveying process and a thermal composite stacking roller at the ending point of the conveying process.

[0010] Preferably, the diaphragm conveying structure provides an upper diaphragm and a lower diaphragm, and the electrode providing mechanism places a positive electrode on the outside of the upper diaphragm and the lower diaphragm and a negative electrode on the inside of the upper diaphragm and the lower diaphragm, respectively.

[0011] Preferably, the upper diaphragm, the lower diaphragm, the positive electrode sheet, and the negative electrode sheet pass between the arc-shaped pressure roller and the conventional roller in the thermal composite lamination roller.

[0012] Preferably, the positive electrode includes a binder, a conductive agent, an additive, an active material, and a current collector; the negative electrode includes a thickener, a binder, a conductive agent, an additive, an active material, and a current collector.

[0013] Preferably, the active material in the positive electrode 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.

[0014] Preferably, the active material in the negative electrode includes at least one of graphite, SiO / C, and Si / C.

[0015] The above technical solution has the following advantages or beneficial effects:

[0016] The curved pressure roller compensates for deflection deformation under working pressure by using the curvature of the roller surface, thus fundamentally solving the problem of uneven pressure distribution. This design ensures the flatness of the electrode and the separator, the reliability of bonding, and the uniformity of air permeability, ultimately improving the cycle life and safety of the battery cell. Attached Figure Description

[0017] Figure 1 A schematic diagram of the structure of a thermal composite stacking roller is shown in a preferred embodiment of this utility model.

[0018] Figure 2 A cross-sectional view of the arc-shaped pressure roller in a preferred embodiment of this utility model;

[0019] Figure 3 This is a schematic diagram of the structure of a stacking machine in a preferred embodiment of the present invention. Detailed Implementation

[0020] 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.

[0021] In a preferred embodiment of the present invention, based on the above-mentioned problems existing in the prior art, a thermal composite stacking roller is provided, including an arc-shaped pressure roller 1 and a conventional roller 2 disposed on one side of the arc-shaped pressure roller, wherein a heating device 3 is integrated in the arc-shaped pressure roller 1.

[0022] Specifically, a conventional flat roller moves downwards and presses down via connecting rods at both ends. When the flat roller encounters resistance upon contact with the electrode, the two ends of the roller are pressed down by the connecting rods, and the middle of the roller undergoes deflection deformation due to the resistance (similar to a "bend in the middle"). This results in an uneven distribution of contact pressure between the roller and the material, with a "lower pressure in the middle and higher pressure on both sides." This uneven pressure leads to excessive compression at both ends of the electrode (forming a "U"-shaped depression), while the middle is not firmly bonded. At the same time, the air permeability of the diaphragm fluctuates due to local pressure differences.

[0023] like Figure 1 As shown, an arc-shaped pressure roller 1 is used in this embodiment. The arc-shaped pressure roller 1 already has a raised arc when no pressure is applied (the middle diameter is slightly larger than the ends). When pressure is applied, the deflection deformation of the roller body under force cancels out the raised arc on the roller surface, making the contact pressure distribution between the roller surface and the material more uniform under actual working conditions, avoiding local overpressure or underpressure. The arc-shaped pressure roller 1, by offsetting the deflection deformation under working pressure through the arc formed on the roller surface, fundamentally solves the problem of uneven pressure distribution. This design ensures the flatness of the electrode and the separator, the reliability of bonding, and the uniformity of air permeability, ultimately improving the cycle life and safety of the battery cell.

[0024] In a preferred embodiment of this utility model, a temperature sensor 11 is provided in both the arc-shaped pressure roller 1 and the conventional roller 2.

[0025] Specifically, temperature sensors 11 are installed in the arc-shaped pressure roller 1 and the conventional roller 2, which can detect whether the heating temperature of the diaphragm and the electrode sheet meets the standard.

[0026] In a preferred embodiment of this utility model, pressure sensors 12 are provided at both ends of the arc-shaped pressure roller and the conventional roller.

[0027] Specifically, pressure sensors 12 are provided at both ends of the arc-shaped pressure roller 1 and the conventional roller 2, which can detect whether the pressure of the arc-shaped pressure roller on the diaphragm and the electrode sheet meets the standard.

[0028] In a preferred embodiment of this utility model, the heating device 3 includes multiple heating tubes 31, each of which is arranged circumferentially along the central axis of the arc-shaped pressure roller 1.

[0029] Specifically, such as Figure 2 As shown, multiple heating tubes 31 are arranged circumferentially around the central axis of the arc-shaped pressure roller 1, which can heat the entire arc-shaped pressure roller more evenly and avoid uneven temperature, which would lead to unsatisfactory hot pressing effect and thus affect the performance of the battery.

[0030] This utility model also provides a stacking machine, including the thermal composite stacking roller as described above, and further including:

[0031] The diaphragm conveying mechanism has an electrode supply mechanism at the starting point and a thermal composite stacking roller at the ending point.

[0032] In a preferred embodiment of the present invention, the diaphragm conveying structure provides an upper diaphragm 100 and a lower diaphragm 200, and the electrode providing mechanism places a positive electrode 300 on the outside of the upper diaphragm 100 and the lower diaphragm 200 and a negative electrode 400 on the inside of the upper diaphragm 100 and the lower diaphragm 200, respectively.

[0033] In a preferred embodiment of this utility model, the upper diaphragm 100, the lower diaphragm 200, the positive electrode 300, and the negative electrode 400 pass between the arc-shaped pressure roller 1 and the conventional roller 2 in the thermal composite stacking roller.

[0034] Specifically, such as Figure 3 The diagram (showing a diaphragm conveying mechanism and electrode supply structure using prior art equipment, not shown) illustrates the diaphragm conveying direction X, in which a pair of positive electrode plates 300 and negative electrode plates 400 and the diaphragm between them form a composite unit plate 600, and the positive electrode plates 300 are alternately placed on the outside of the upper diaphragm 100 and the outside of the lower diaphragm 200.

[0035] Preferably, the diaphragm surface is coated with an adhesive layer, and the base film of the coated diaphragm includes, for example, polypropylene (PP), polyethylene (PE), polypropylene / polyethylene / polypropylene (PP / PE / PP), polyamide (PA), or polyimide (PI); the adhesive layer of the coated diaphragm includes, for example, an oil-based adhesive layer or a water-based adhesive layer, and 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.

[0036] During the cell manufacturing process, the coated separator and negative electrode 400 are heated and then bonded to the inner side of the two separators by a hot composite stacking roller. Subsequently, the heated positive electrode 300 is bonded to the outer side of the two separators by a pressure roller. Finally, each small unit is stacked in a "Z" shape to form a core.

[0037] Thermal lamination involves separating positive and negative electrode sheets of a specified width and length with an adhesive-coated separator, and then continuously stacking them in a positive electrode sheet / adhesive-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.

[0038] Because of the arc-shaped pressure roller 1, the battery cell is not affected by uneven force caused by the deflection of the pressure roller during the trial production process. This can overcome the uneven pressure on the electrode and diaphragm caused by the deflection of the pressure roller, effectively improve the problems of the "U" shape of the electrode and uneven air permeability of the diaphragm, and further improve the cycle life of the battery cell.

[0039] In a preferred embodiment of this invention, the positive electrode includes a binder, a conductive agent, an additive, an active material, and a current collector; the negative electrode includes a thickener, a binder, a conductive agent, an additive, an active material, and a current collector.

[0040] In a preferred embodiment of this invention, the active material in the positive electrode includes 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 material, and 5V spinel.

[0041] In a preferred embodiment of this invention, the active material in the negative electrode includes at least one of graphite, SiO / C, and Si / C.

[0042] 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 thermal composite laminating roller, characterized in that, It includes an arc-shaped pressure roller and a conventional roller located on one side of the arc-shaped pressure roller, and a heating device is integrated in the arc-shaped pressure roller.

2. The thermal composite laminating roller according to claim 1, characterized in that, Temperature sensors are provided in both the arc-shaped pressure roller and the conventional roller.

3. The thermal composite laminating roller according to claim 1, characterized in that, Pressure sensors are provided at both ends of the arc-shaped pressure roller and the conventional roller.

4. The thermal composite laminating roller according to claim 1, characterized in that, The heating device includes multiple heating tubes, each of which is arranged circumferentially along the central axis of the arc-shaped pressure roller.

5. A stacking machine, characterized in that, Including the thermal composite stacking roller as described in claims 1-4, further comprising: The diaphragm conveying mechanism has an electrode providing mechanism at the starting point of the conveying process and a thermal composite stacking roller at the ending point of the conveying process.

6. The stacking machine according to claim 5, characterized in that, The diaphragm conveying structure provides an upper diaphragm and a lower diaphragm, and the electrode providing mechanism places a positive electrode on the outside of the upper diaphragm and the lower diaphragm and a negative electrode on the inside of the upper diaphragm and the lower diaphragm, respectively.

7. The stacking machine according to claim 6, characterized in that, The upper diaphragm, the lower diaphragm, the positive electrode sheet, and the negative electrode sheet pass between the arc-shaped pressure roller and the conventional roller in the thermal composite lamination roller.

8. The stacking machine 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; the negative electrode includes a thickener, a binder, a conductive agent, an additive, an active material, and a current collector.

9. The stacking machine according to claim 8, characterized in that, The active material in the positive electrode 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.

10. The stacking machine according to claim 8, characterized in that, The active material in the negative electrode includes at least one of graphite, SiO / C, and Si / C.

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