A doped single crystal ternary positive electrode material coated with mesoporous lithium aluminum silicate and preparation method thereof

Abstract

The invention belongs to the technical field of lithium ion battery electrode materials, and discloses a mesoporous lithium aluminum silicate coated doped single crystal ternary positive electrode material and a preparation method thereof, and particularly relates to a doped single crystal lithium nickel cobalt manganate ternary material (LiNi0.55CoxMnyM1-x-yO2@(LiAlSi2O6)z) coated with a mesoporous lithium aluminum silicate layer and a preparation method thereof. According to the preparation method disclosed by the invention, a single-crystal doped lithium nickel cobalt manganate base material is obtained through an in-situ doping co-precipitation-high-temperature solid-phase method; and the mesoporous lithium aluminum silicate layer with high speed lithium ions and electron channels is coated through a template-sol / gel-low-temperature annealing process to prepare the doped single crystal lithium nickel cobalt manganate positive electrode material (LiNi0.55CoxMnyM1-x-yO2@(LiAlSi2O6)z), wherein the material has a high first specific capacity of 185.5mAh / g, high high-voltage cycling stability and excellent rate performance.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion battery electrode materials, in particular to a doped single-crystal ternary positive electrode material coated with mesoporous lithium aluminum silicate and a preparation method thereof, in particular to a surface-coated mesoporous lithium aluminum silicate layer The doped single crystal nickel cobalt lithium manganese oxide ternary material (LiNi 0.55 co x mn y m 1-x-y o 2 @(LiAlSi 2 o 6 ) z ) and its preparation method. Background technique [0002] Nickel cobalt lithium manganate (NCM) ternary cathode material (LiNi x co y mn 1-x-y o 2 , 0<x, y<1) Due to the advantages of high energy density, good safety performance, and low cost, and the ratio of nickel, cobalt, and manganese can be adjusted, ternary cathode materials with different properties can be prepared, becoming a new generation Lithium battery cathode material. At present, the commercialized NCM ternary cathode ...

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Problems solved by technology

For example, the patent ZL201610443127.X discloses a single crystal nickel-cobalt lithium manganese oxide cathode material obtained by high-temperature sintering doping and high-temperature sintering coating. Although the material has better cycle performance than the undoped and coated ternary substrate, However, doping and cladding are all achieved through solid-state high-temperature sintering. The uniformity of doping and cladding is not good, and the material is too hard. It is easy to damage the surface of the material during the crushing process and aggravate the degree of side reactions on the surface of the material. shorten the cycle life of the material

Another example is patent ZL201610989907.4, which discloses a ternary material for obtaining a silver-loaded mesoporous silica coating layer through a two-step method. Although the surface coating layer of this material has a high-speed electron channel, the surface silica cannot increase the lithium ion density. , will reduce the initial capacity of the material to a certain extent, and the coating process is complicated, and the cost is high, so it cannot be mass-produced

It can be seen that the current doping or coating methods have not been able to solve the defect of poor high-voltage cycle stability of ternary materials.

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