A method of chemical vapor deposition coated carbon and the prepared coated high-voltage ternary material

Abstract

The invention discloses a method for coating carbon by chemical vapor deposition and the prepared coated high-voltage ternary material. Firstly, the ternary material is generated in a dynamic chemical vapor deposition furnace, and then the liquid titanium source is vaporized to utilize the ternary material in a dynamic chemical vapor deposition furnace. Oxidative decomposition in an oxygen atmosphere, a chemical vapor deposition reaction occurs at the interface of the ternary material, and a ternary material with uniform and dense coating of titanium oxide is generated in situ; then carbon coating is carried out in a series of two-stage vapor deposition furnaces; finally through Crushed, sieved, and packaged to get the final product. The invention significantly improves the uniformity and compactness of the coating by coating titanium oxide in the gas phase, and effectively solves the problem of carbon reduction of metal elements of ternary materials under high temperature conditions through the design of the secondary vapor deposition furnace process; chemical vapor deposition The kiln is a dynamic kiln, so the one-time roasted product will not harden, and can continue to be coated, which greatly simplifies the process flow.

Description

technical field [0001] The invention relates to the field of cathode materials for lithium-ion secondary batteries, in particular to a method for coating carbon by chemical vapor deposition and the prepared coated high-voltage ternary material. Background technique [0002] The promotion and application of new energy vehicles is imperative, among which the power lithium-ion battery is the core part of new energy vehicles, and the positive electrode material in the lithium-ion battery system is the decisive factor. In the existing cathode material system, ternary materials have the advantages of high specific energy density and good cycle performance, and are the mainstream materials for new energy vehicles. However, the existing conventional ternary materials will be oxidized to tetravalent nickel during the charging process of divalent nickel and trivalent nickel, and tetravalent nickel has a strong catalytic and oxidative effect on the existing carbonate electrolyte system...

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Problems solved by technology

In the prior art CN 108963239A, a positive electrode material of nickel-cobalt-lithium-manganese oxide coated with titanium dioxide was prepared by vapor deposition, but as titanium dioxide is a semiconductor, the separate coating will affect the specific capacity of the material; in the prior art CN106058220B, the vapor deposition method was also used to prepare Titanium nitride and carbon double-coated cathode material, but it adopts the traditional solid-phase carbon source roasting method to form a carbon layer. The carbon source precursor is prone to aggregation at high temperature, and the roasted product also has uneven coating. In addition, at high temperature, carbon will undergo a reduction reaction with metal ions in the positive electrode material, which will cause some metal segregation in the material and affect the performance of the positive electrode material.

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