A lithium cobalt oxide material and a lithium ion battery

Abstract

The invention discloses a lithium cobalt oxide material and a lithium ion battery. The preparation method of the lithium cobaltate material comprises the following steps: S1. The precursor of CoxNiyZnz (OH) is synthesized by coprecipitation method with metal sulfate as raw material and NaOH and NH3.H2O as precipitant, wherein Ni-Zn metal ion content is 6-10 wt%, and Ni-Zn co-doped Li(CoxNiyZnz)O2was synthesized by lithium complexing and solid-state method; S2. the surface of the material obtained in S1 is coated with a layer of 3-6[mu]m thick Co3O4 metal oxide, wherein that Co3O4 occupy 2.0-5.0 wt%, and reaction is performed at 600-800 DEG C to obtain that lithium cobalt oxide material. As that lithium cobalt oxide material is use as the cathode material of the lithium ion battery, the lithium cobalt oxide material can remarkably improve the cycling stability and the cycling capacity retention rate of the material without reduce the initial discharging capacity of the material. The graphene added in the cathode material in the electrode manufacturing process has good thermal conductivity and electrical conductivity, and can improve the rate performance and safety performance of the lithium ion battery; And the thickness expansion ratio of lithium ion batteries at high temperature is reduced from 60% to 15%.

Description

technical field [0001] The invention belongs to the field of polymer lithium ion batteries, and more specifically relates to a lithium cobalt oxide material and a lithium ion battery. Background technique [0002] Energy plays an important role in the development of modern society. Traditional fossil fuels are gradually unable to meet the needs of the rapid development of the global economy. And fossil fuels will also bring environmental pollution and greenhouse effect. The development of new clean energy sources has been widely demanded, such as: solar energy, wind energy, tidal energy and geothermal energy. However, these energy sources are unstable in time and space, and require conversion for utilization and storage. [0003] Li-ion batteries are the most efficient energy storage devices due to their commercial production and their combination of high open circuit voltage, large discharge capacity, long service life and no pollution to the environment. Lithium-ion ba...

AI Technical Summary

Problems solved by technology

[0007] 1. Due to the high potential of the positive electrode material and the strong oxidation of the positive electrode material in the high delithiation state, side reactions with the organic electrolyte will continue to occur during battery storage and use, resulting in deterioration of the battery performance

[0008] 2. When the lithium-ion battery voltage reaches the charging upper limit of 4.4V, the deintercalation ratio of lithium ions exceeds 60%, which will cause the collapse of the layered structure of lithium cobalt oxide. After charging and discharging, the battery capacity will be seriously lost, and the cycle performance will drop sharply , but also due to the serious damage to the structure of the positive electrode material, the thermal stability of the battery will decrease.

[0009] 3. The electrochemical window of the conventional electrolyte cannot meet the requirements of the charging upper limit voltage of 4.4V. Using it in a battery using a 4.4V lithium cobalt oxide system will lead to battery flatulence, low capacity, etc., and even cause serious safety hazards