Surface in-situ coated lithium-enriched material and preparation method thereof

Abstract

The invention discloses a surface in-situ coated lithium-enriched material. Raw materials comprise a coating layer and a lithium-enriched material precursor, the raw material of the coating layer is a compound of a metal Me, the lithium-enriched material precursor is a mixture of at least one of oxide of MnMA, hydroxide, carbonate and oxalate and a lithium source, wherein Me and M are metal elements; and A is at least one of S, P, B and F. The invention further discloses a preparation method. A metal compound coats lithium-enriched material precursor particles, and then the lithium-enriched material precursor particles are sintered at high temperature to form a lithium-enriched material of which the surface is coated with spinel-containing oxide. The surface in-situ coated lithium-enriched material has the advantages that the surface stability and the conductivity of the surface in-situ coated lithium-enriched material are greatly improved, and therefore, the charging-discharging specific capacity, the efficiency, the multiplying power and the circling performance of the material are obvious improved. The surface in-situ coated lithium-enriched material is simple in preparation process, low in cost, good in result reproducibility and suitable for large-scale popularization.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, in particular to a lithium-rich material with in-situ coating on the surface and a preparation method thereof. Background technique [0002] Due to the characteristics of high energy density, long cycle life, environmental protection, and low cost, lithium-ion batteries have developed rapidly in more than 20 years, and their applications involve communications, transportation, military, medical, entertainment, and many other fields. In recent years, with the rapid development of electric vehicles, high specific energy and high power lithium-ion batteries have become an inevitable direction for the development of lithium-ion batteries in the future. Currently commercial cathode materials such as LiCoO 2 、LiFePO 4 , LiMn 2 o 4 , ternary materials, etc., with low specific capacity (<200mAh / g). The cathode material is the main factor limiting the specific energy of the battery. ...

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Problems solved by technology

[0005] The methods in the above-mentioned prior art are relatively complicated and not easy to scale up. For example, the liquid-phase method is used to post-coat the finished product of lithium-rich material. It is necessary to first immerse the finished product of lithium-rich material in the solution, and then undergo precipitation. , Filtration, washing, drying, heat treatment and a series of processing processes, in addition, there are problems such as uneven coating layer, insufficient bonding degree of coating layer and lithium-rich materials, etc.

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