Coating method and coating machine for lithium battery negative electrode slurry

Abstract

The invention relates to a coating method and a coating machine for lithium battery negative electrode slurry. The coating method comprises the following steps of performing temperature control treatment on the negative electrode slurry, controlling the temperature of the negative electrode slurry to be 40-60 DEG C to enable the viscosity of the negative electrode slurry to meet the coating requirement, and then performing coating. The coating method provided by the invention can realize normal coating of the negative electrode slurry with high solid content, so that the coating effect is improved, and the coating energy consumption is reduced; and meanwhile, the viscosity consistency of different batches of slurry is improved, so that the coating consistency of the negative electrode slurry is improved.

Description

technical field [0001] The invention belongs to the field of negative electrode slurry coating, and relates to a coating method of lithium battery negative electrode slurry and a coating machine thereof. Background technique [0002] In the coating process of lithium battery manufacturing, the viscosity of the negative electrode slurry needs to be controlled within 2000-6000cP in order to meet the requirements of the coating die for the rheological properties of the slurry. Because the viscosity of the negative electrode slurry is positively correlated with its solid content, the solid content of the negative electrode slurry needs to be less than 50%, thus limiting the application of high solid content slurry. Moreover, the solid content of the negative electrode slurry is negatively correlated with the energy consumption of the coating oven, and a lower solid content means that higher energy consumption is required for coating. Therefore, in general, although the low soli...

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Problems solved by technology

[0004] CN110120555A discloses a preparation method of a lithium battery with a high cycle life. It prepares a negative electrode slurry with a solid content of 30% to 35%, makes highly flexible positive and negative pole pieces, and winds the positive pole piece, diaphragm and negative pole piece The lithium battery cell is machine-made, the lithium battery cell is packaged in the casing, and the lithium battery is generated by rolling grooves, welding caps, and liquid injection; the solid content of the negative electrode slurry used in this scheme is low, which leads to high in the coating process. Energy consumption, and does not give a method suitable for high solid content negative electrode slurry coating

[0005] CN107799719A discloses a lithium battery negative electrode formulation and a coating process using the formulation, which can improve the polarity of the electrode by adjusting the ratio of ethylene carbonate, adding a small amount of absolute ethanol and appropriately increasing a certain amount of N-methylpyrrolidone. Flexibility, eliminate the foam phenomenon of the coating machine head; the solid content of the negative electrode slurry disclosed in this scheme is only 39% to 41%, resulting in high energy consumption in the coating process, and no suitable high solid content negative electrode slurry is given. Coating method

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