A kind of multi-metal composite oxide coated lithium-rich manganese-based positive electrode material and preparation method thereof

Abstract

The invention discloses a multi-metal composite oxide-coated lithium-rich manganese-based positive electrode material, in which a multi-metal (Li, Gd, Nb, Zr and Sr) composite oxide layer is coated on the surface of a substrate. Its preparation method: pre-activate the nano-metal; add the pre-activated metal powder and polymer compound into the lithium-containing solution for reaction, then ultrasonically disintegrate the cells, and then add the lithium-rich manganese-based cathode material matrix, multi-functional The disperser is stirred and heated at the same time to form a gel; the gel is added to the mechanical fusion machine, and the mechanical pre-mixing is carried out at a low speed, and then the high-speed mechanical fusion is carried out to complete the coating of the material; the final annealing treatment is naturally cooled with the furnace , to obtain a multi-metal composite oxide-coated lithium-rich manganese-based positive electrode material. The coating layer on the surface of the lithium-rich manganese-based positive electrode material matrix of the present invention can prevent the reaction between the electrode and the electrolyte, and prevent the phenomenon of capacity decay or cycle performance deterioration of the lithium-rich manganese-based positive electrode material matrix.

Description

technical field [0001] The invention belongs to the field of battery materials, in particular to a multi-metal composite oxide-coated lithium-rich manganese-based positive electrode material and a preparation method thereof. Background technique [0002] At present, the research and development of cathode materials for lithium-ion batteries is lagging behind, which has become one of the factors restricting the further development of the lithium battery industry. In recent years, the state has proposed that the specific energy of power batteries will reach 350Wh / kg by 2020, so the demand for new high-capacity cathode materials for lithium-ion power batteries is more urgent. [0003] Compared with traditional cathode materials, lithium-rich manganese-based layered cathode materials Li[Li 1-x-y-z Ni x co y mn z ]O 2 It is cheap, more environmentally friendly, has a charging mechanism different from traditional cathode materials, the charging voltage can be as high as 4.5V,...

AI Technical Summary

Problems solved by technology

[0008] In order to solve the problems that the secondary particles of the lithium-rich manganese-based positive electrode material are cracked or even broken, improve the cycle performance and rate performance of the material, and the coating layer is easy to fall off and the coating is uneven, the technical solution proposed by the present invention is:

Images