Liquid-phase two-component-coated Cu<2+> and Cr<3+>-doped amorphous nickel nitrate lithium battery anode material and preparation method thereof

Abstract

The invention relates to a liquid-phase two-component-coated Cu<2+> and Cr<3+>-doped amorphous nickel nitrate lithium battery anode material and a preparation method thereof. The method is characterized by comprising the steps of synthesizing Cu<2+> and Cr<3+>-doped amorphous nickel nitrate by using a solvent conversion method, and coating Cu<2+> and Cr<3+>-doped amorphous nickel nitrate particles with ZnO and TiO2 so as to form the two-component-coated Cu<2+> and Cr<3+>-doped amorphous nickel nitrate lithium battery anode material; then, removing crystallization water in a system by adopting a special heat treatment step under the high vacuum condition. The material is coated with the ZnO, so that the electric conductivity of the material is greatly improved; the material is coated with the TiO2, so that the electrolyte erosion resistance of the material is improved. The system is internally doped with Cr<3+>, so that the electronic conductivity of the system is improved, and the vacancy defect in the system is increased; the system is internally doped with Cu<2+>, so that an Ni-O space structure has distortion, a lithium ion diffusion migration channel is expanded, and the lithium ion conductivity is increased; the liquid-phase two-component-coated Cu<2+> and Cr<3+>-doped amorphous nickel nitrate lithium battery anode material has the particularly beneficial effect that the material is an amorphous body and has isotropy, thus being beneficial to rapid conduction of lithium ions. Therefore, the comprehensive electrochemical performance of nickel nitrate is greatly improved.

Description

technical field [0001] The invention relates to the technical field of a method for manufacturing a high-performance nickel nitrate composite lithium battery negative electrode material. Background technique [0002] Lithium-ion secondary batteries have the absolute advantages of high volume, weight-to-energy ratio, high voltage, low self-discharge rate, no memory effect, long cycle life, and high power density. Currently, the global mobile power market has an annual share of more than 30 billion US dollars and Gradually grow at a rate of more than 10%. Especially in recent years, with the gradual depletion of fossil energy, new energy sources such as solar energy, wind energy, and biomass energy have gradually become alternatives to traditional energy sources. Among them, wind energy and solar energy are intermittent, and a large amount of energy is used simultaneously to meet the needs of continuous power supply. Energy storage batteries; urban air quality problems caused...

AI Technical Summary

Problems solved by technology

However, it is still very difficult to take into account the rate performance and cycle capacity retention performance of the material.

The main reasons are as follows: 1. When the redox reaction occurs, the electrode material should have fast lithium ion intercalation and deintercalation and electronic conduction, that is, it should have good electronic conductivity and ion conductivity at the same time. Many negative electrode materials have high However, it is an electronic insulator, which greatly increases the polarization of the battery; 2. Many electrode materials have a large volume change during the process of lithium ion intercalation and deintercalation, resulting in electrode material particles The broken and effective electrode materials are lost during the cycle, and the large volume change also brings about the transformation of the material lattice during the charging and discharging process to produce a second phase, which seriously affects the performance of the battery.

3. Lithium battery negative electrode material with conversion reaction mechanism, the electronic insulation of the reaction product lithium compound seriously affects the reversibility of the material

Nickel nitrate negative electrode conversion material can also provide close to or exceed 1000mAh.g -1 The specific capacity, and its rate characteristics are superior to those of metal oxides, sulfides, phosphides, carbonates, and chlorides, and the volume change of materials that lithium ions enter or exit is also small; and its main problems are: 1. Nitric acid Nickel generally contains a lot of crystal water, and these crystal water is difficult to completely remove and it is easy to cause electrolyte decomposition to corrode the surface of the material and partially dissolve the material itself; 2. The product lithium nitrate after the conversion reaction is an electronic insulator and its lithium ions The diffusion activation energy is also high, resulting in a large electrochemical polarization; 3. The surface of nickel nitrate is unstable and easily corroded by the electrolyte

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