Freeze-drying-based lithium ion battery positive electrode lithium supplementing method and product

Abstract

The invention belongs to the technical field of lithium batteries, and more specifically relates to a freeze-drying-based lithium ion battery positive electrode lithium supplementing method and a freeze-drying-based lithium ion battery positive electrode lithium supplementing product. The lithium supplement agent is dissolved in the aqueous solvent and is uniformly mixed with the positive active material to prepare slurry, the slurry is coated on the current collector, then the lithium supplement agent is cooled, crystallized and separated out into lithium supplement agent particles with small sizes through freezing, and the lithium supplement agent particles are uniformly attached to the surface of the positive active material. According to the low-temperature and low-pressure gasification drying method, a solid aqueous solvent is directly removed through sublimation, and finally, small-size lithium supplement agent crystal grains and a positive electrode active material are uniformly mixed and distributed in the final battery positive electrode material. As the crystal grains of the lithium supplement agent are refined, and the uniform dispersion of the lithium supplement agent and the positive electrode active material can be promoted, the lithium supplement method can obviously reduce the decomposition voltage of the lithium supplement agent, and finally the electrochemical performance of the battery assembled by the positive electrode material after lithium supplement is improved.

Description

technical field [0001] The invention belongs to the technical field of lithium batteries, and more specifically relates to a freeze-drying-based method and product for replenishing lithium at the positive electrode of a lithium-ion battery. Background technique [0002] Lithium-ion batteries have the advantages of high specific energy, long cycle life, high working voltage, small self-discharge and no memory effect, and have been widely used in electric vehicles and energy storage systems and other fields. At present, the research on lithium-ion batteries has made great progress, but during the first charging process of lithium-ion batteries, a solid electrolyte layer is formed on the surface of the negative electrode, which consumes the active lithium in the positive electrode, resulting in an irreversible lithium loss of up to 7-15%, resulting in The energy density and cycle performance of lithium-ion batteries are reduced. [0003] At present, the main ideas of lithium s...

AI Technical Summary

Problems solved by technology

However, this type of lithium supplementation agent has a high oxidation decomposition potential, and it is mostly used together with a high-voltage spinel system. In addition, the positive electrode lithium supplementation agent has requirements for the stability of air and water, and it needs to be better compatible with the current positive electrode coating. cloth craft

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