Method for preparing uniform lithium ion battery ternary cathode material by one-step in-situ complexation

Abstract

The invention discloses a method for preparing a uniform lithium ion battery ternary cathode material by one-step in-situ complexation. The method uses organic sugar as a solvent, uses urea as a co-solvent and a gas template agent, and comprises firstly melting the organic sugar and the urea in proportion; then mixing a metal precursor with the molten sugar and urea to form a homogeneous system; performing a drying process to preliminarily and rapidly remove the remaining solvent in order that the metal ions are fixed in situ to an amide group formed by the sugar and urea; subjecting the organic sugar to polymerization and carbonization at a high temperature by using a high-temperature processing method, enabling the urea to generate a gas to uniformly distribute the metal ions to finallyform a nano composite material having a uniform particle size. The method uses a waterless system, and the synthesis method is simple, easy to operate, and friendly to environment. The synthesized ternary material has a uniform particle size maintained at a nanometer level, and has a proper specific surface area. The specific composition, the capacity and the porosity of the ternary material can be flexibly controlled. The method has important research and application significance in the field of cathode materials of lithium ion batteries.

Description

technical field [0001] The invention belongs to the technical field of new energy materials, and in particular relates to a method for preparing a uniform lithium-ion battery ternary cathode material by one-step in-situ complexation. Background technique [0002] With the increasingly serious problem of energy shortage, lithium-ion batteries that do not consume traditional energy and have high energy density have become a hot spot of concern in various countries. The improvement of the performance of lithium-ion batteries mainly depends on the preparation and continuous development of cathode materials. The structures of the two positive electrode materials that have entered the industrialization process at this stage are mainly olivine structure and layered structure. The olivine structure is mainly lithium iron phosphate material, and the layered structure material is mainly lithium cobalt oxide material and its corresponding derivatives. However, due to factors such as l...

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Problems solved by technology

The solid-phase method has low equipment requirements, simple process, and is suitable for large-scale production. However, the uniformity of the product is not high, the particle shape distribution is uneven, and the large energy consumption is a fatal shortcoming. Poor shape will directly lead to unstable battery performance. ; The material formed by the hydrothermal method is uniform in distribution, high in purity, easy to control the particle size of the material, and the preparation process is relatively simple, but the yield is low, and it is not suitable for large-scale production; the material prepared by the sol-gel method has extremely low impurity content. The prepared battery has good cycle performance, but some metal alkoxides involved in the raw materials used in this method are toxic, and the synthesis cycle is long, so it is not suitable for mass production

[0004] To sum up, the existing synthesis methods of ternary cathode materials for lithium-ion batteries still have many disadvantages. The complex process, long time-consuming, and high cost have become obstacles to the large-scale industrialization of this material; and the easy-to-operate synthesis methods have The purity of the obtained positive electrode material and the uniformity of particle size distribution cannot be fully guaranteed, which will affect the cycle performance and stability of the assembled battery

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