Preparation method of negative electrode of lithium ion battery

Abstract

The present invention provides a lithium ion battery negative electrode preparation method. The preparation method comprises the steps: providing a first graphite material, a second graphite material and a third graphite material, wherein the average particle size D1 of the first graphite material is 2.2-2.4 microns, and the average particle size D2 of the second graphite material is equal to k1 * D1, k1 is in the range of 1.42 to 1.45, the average particle size D3 of the third graphite material is equal to k2 * D1, and k2 is in the range of 0.56 to 0.58; mixing a first graphite material, a second graphite material and a third graphite material according to a preset mass ratio, wherein the first graphite material: the second graphite material: the third graphite material is 1: (c1 * k1): (c2 * k2), and c1 is 0.56, and c2 is 0.82; adding a binder, a graphite material and a conductive agent into deionized water in sequence to obtain negative electrode slurry, coating a negative electrode current collector with the negative electrode slurry, performing drying, carrying out hot pressing to obtain a pole piece, putting the pole piece and a counter electrode lithium piece into an electrolyte, carrying out electrochemical lithium pre-embedding, taking the pole piece out of the electrolyte, and performing drying to obtain the negative electrode. The negative electrode obtained by the preparation method disclosed by the invention is high in energy density and long in cycle life.

Description

technical field

[0001] The invention relates to a preparation method of a negative pole of a lithium ion battery. Background technique

[0002] The negative electrode of the power lithium-ion battery is one of the key materials of the power lithium-ion battery. After a long-term charge and discharge cycle, the active material layer of the negative electrode will fall off, and problems such as lithium metal dendrites will be generated when lithium ions are intercalated and deintercalated, which will affect the performance of power lithium-ion batteries. The cycle life of the ion battery, how to improve the stability of the negative electrode active material layer, is one of the key factors to improve the battery life. Contents of the invention

[0003] The invention provides a method for preparing a negative electrode of a lithium ion battery. The preparation method includes providing a first graphite material, a second graphite material and a third graphite material, and t...

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