High-capacity lithium cobalt oxide-base lithium ion battery anode material and preparation method thereof

Abstract

The invention discloses a high-capacity lithium cobalt oxide-base lithium ion battery anode material. The material is a lithium cobalt oxide finished product which is obtained by mixing modified lithium cobalt oxide in different granularities and coating the lithium cobalt oxide, the anode material contains a cobalt-source substance, a lithium-source substance, a doping agent and a coating material, wherein the molar ratio of Li to Co is 0.95 to 1.2, the doping quantity of the doping agent is 0.01 to 10 percent by weight, and the doping quantity of the coating material is 0.01 to 20 percent by weight. The capacity of the lithium cobalt oxide material is improved by mixing the lithium cobalt oxide in different granularities, the stability, safety and electrochemical property of the material under the high voltage condition of more than 4.2V are improved through doping and coating, and the high-temperature circulating property is improved.

Description

technical field [0001] The invention relates to a lithium ion battery cathode material and its preparation, in particular to a high-capacity lithium cobaltate-based lithium ion battery cathode material and a preparation method thereof. Background technique [0002] With the rapid development of electronic technology and the continuous upgrading of electronic products, the requirements for the energy density of batteries are also getting higher and higher. At present, the charging voltage of the conventionally used small lithium-ion battery is 4.2V. The smart high-end electronic products represented by the American Apple Company and the South Korean Samsung Company have updated the batteries used in their own products to increase the battery voltage to 4.3V. , 4.35V or higher high-voltage batteries. Increasing the charging voltage of the battery can significantly increase the capacity of the battery without increasing the active material in the battery. It is one of the effe...

AI Technical Summary

Problems solved by technology

[0004] There are other ways to increase the capacity of lithium-ion secondary batteries: (a) Chinese patent CN 1665052A increases the compaction density of the material by mixing lithium cobalt oxides of different particle sizes, thereby increasing the capacity per unit volume to achieve high capacity, Due to its small particle size, it brings potential safety hazards to the battery; (b) Chinese patent CN 101436666A proposes to prepare large particles of lithium cobalt oxide material first, and then use cobalt carbonate and lithium carbonate to form large lithium cobalt oxide particles on the surface. particles, so that small particles of lithium cobaltate particles adhere to the surface of large particles, thereby increasing the tap density and volume specific capacity of the positive electrode material, but the crystallinity of lithium cobaltate sintered once is not good, which will affect the cycle performance of the battery ; (c) Chinese patent CN 102779976A proposes mixing lithium cobalt oxides of different sizes, and then undergoing doping, sintering, coating, sintering and other processes to improve compaction density and safety performance, etc.

However, the process is complicated and increases the production cost