Lithium-ion battery with high rate performance and preparation method thereof

Abstract

The invention relates to a preparation method of a lithium-ion battery with high rate performance. The preparation method comprises the steps of adopting an active material with the particle size D50 of 1.0-1.5 microns as a cathode active material; mixing the cathode active material, a conductive agent and a binder with a solvent, and mixing and dispersing to obtain negative electrode paste; coating the negative electrode paste on a current collector according to a coating weight per unit area of 255+ / -5 g / m2 and drying to obtain a negative electrode piece; adopting an active material with the particle size D50 of 8.0-8.5 microns as an anode active material, mixing the anode active material, the conductive agent and the binder with the solvent, and mixing and dispersing to obtain active electrode paste; coating the active electrode paste on the current collector according to a coating weight per unit area of 121+ / -5 g / m2 and drying to obtain a positive electrode piece, wherein the conductive agent comprises a tube bundle conductive agent and a granular conductive agent; and assembling the negative electrode piece, the positive electrode piece and a diaphragm to form a battery. The battery prepared by the preparation method has the advantages such as short charging time and excellent rate performance.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, more specifically, to a lithium ion battery with high rate performance and a preparation method thereof. Background technique [0002] At present, lithium-ion batteries have been widely used in various fields such as electric tools, electric vehicles, and grid energy storage. The batteries in China are rapidly changing from ordinary batteries of nickel-metal hydride and nickel-cadmium to lithium-ion batteries with higher energy density and environmental protection. In recent years, lithium-ion batteries have experienced explosive growth in the automotive field. [0003] At present, rate-type lithium-ion batteries account for a relatively small proportion in the entire industry. The problem lies in: the charging and discharging current of lithium-ion batteries is relatively small and the time is long; they cannot withstand high-current fast charging; It can effectively intercalate into the a...

AI Technical Summary

Problems solved by technology

[0003] At present, rate-type lithium-ion batteries account for a relatively small proportion in the entire industry. The problem lies in: the charging and discharging current of lithium-ion batteries is relatively small and the time is long; they cannot withstand high-current fast charging; Can effectively intercalate the anode, leading to lithium precipitation, thereby reducing the service life of the battery

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