Preparation method of novel lithium ion battery cathode material

Abstract

The invention discloses a preparation method of a novel lithium ion battery cathode material. The method includes the following steps: 1) producing lithium carbonate; 2) mixing a cobalt salt with a complexing agent, adding the mixture as well as a precipitator into a reactor, performing a reaction to produce a solid, and sintering the solid with the lithium carbonate to prepare a lithium cobalt oxide material; 3) mixing deionized water and ethylene glycol, as solvents, with graphene oxide to obtain a graphene oxide dispersant, adding the self-made lithium cobalt oxide material, and performing ultrasonic treatment to obtain a mixed dispersant; 4) dropping the mixed dispersant to a receiving solution, of which temperature is controlled by a low-temperature freeze bath, successively performing freeze-drying and vacuum-drying to obtain a solid, adding the solid to a crosslinker solution for treatment, and treating the solid in a hydrazine hydrate solution; 5) drying the solid to prepare the lithium ion battery cathode material. The lithium ion battery cathode material has high stability, large specific capacity and excellent rate capability and cycle performance.

Description

Technical field: [0001] The invention relates to the field of lithium ion batteries, in particular to a preparation method of a novel lithium ion battery cathode material. Background technique: [0002] Lithium-ion batteries have the advantages of long cycle life, high power density, high energy density, and high voltage platform. They have been widely used in mobile phones, laptop computers and other electronic products, but it is still difficult to meet the requirements of electric vehicles, electric tools and other products. and safety requirements. Cathode material is a key factor affecting battery performance. [0003] At present, lithium cobalt oxide and lithium manganese oxide are the most commonly used cathode materials for lithium-ion batteries. Lithium cobalt oxide has high capacity and low safety. Lithium manganate has high safety but low capacity. Reaching 160mAh / g, the gram capacity of lithium manganese oxide is only 130mAh / g. How to improve the safety perform...

AI Technical Summary

Problems solved by technology

[0004] Chinese patent (CN201310087193.4) ​​discloses a preparation method of high specific capacity graphene-coated nickel-cobalt lithium manganate material, which mainly solves the low discharge specific capacity of nickel-cobalt lithium manganate existing in the prior art, As for high-nickel nickel-cobalt lithium manganese oxide, nickel and lithium are prone to mixed discharge inside the material, resulting in the precipitation of lithium. When the air humidity is high, the phenomenon of lithium precipitation is more serious and other technical problems.

It is covered with porous graphene, which solves the problem of poor ion conductivity caused by graphene completely and uniformly covering the positive electrode material of lithium-ion batteries, but its pore size is not easy to control, and the modified lithium-ion positive electrode material Conductivity needs to be further improved