SiO<2> coated Co<2+>-Cu<2+> doped amorphous nickel nitrate lithium battery negative electrode material and preparation method thereof

Abstract

The invention discloses a SiO<2> coated Co<2+>-Cu<2+> doped amorphous nickel nitrate lithium battery negative electrode material. The preparation process is as follows: coating SiO<2> on Co<2+>-Cu<2+> doped amorphous nickel nitrate particles in combination with a micro-emulsion and a spray-drying method, thereby resisting the erosion of an electrolyte; and then, under a high vacuum condition, removing crystallization water in a system by adopting a special heat treatment step to form the SiO<2> coated Co<2+>-Cu<2+> doped amorphous nickel nitrate lithium battery negative electrode material. As Co<2+> is doped in the system, the electronic conductivity of the system is improved; with Cu<2+> ions, a Ni-O space structure is enabled to produce distortion and a lithium ion diffusion-migration channel is expanded so that the electric conductivity of lithium ions is improved; the particularly beneficial effect is that the material is amorphous and is isotropic, thereby being conductive to rapid conduction of the lithium ions; and thus, the overall 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 contains a lot of crystal water, and it is difficult to completely remove these crystal water, which may easily cause the electrolyte to decompose, erode the surface of the material and partially dissolve the material itself; The 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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