Continuous conductive liquid-phase synthesized C/Cu, Zn/CuF<2> lithium battery positive electrode material and preparation method

Abstract

The invention discloses a continuous conductive liquid-phase synthesized C / Cu, Zn / CuF<2> composite copper fluoride lithium ion battery positive electrode material and a preparation method therefor. According to the preparation method, by virtue of design of a mixing way of reaction raw materials which comprise copper sulfate pentahydrate and ammonium fluoride, and an adding way and adding rate of water, generation of multiple kinds of compound salt of copper fluoride and other secondary reaction products in a liquid phase reaction can be avoided; meanwhile, by means of a drying process in a low-temperature and high-vacuum condition and a subsequent heat treatment process, a high-conductivity and continuous carbon film with holes and a gap structure can be formed; in addition, a certain amount of copper and zinc are subjected to in-situ reduction on the surface of copper fluoride granules in an in-situ manner; copper provides a homogeneous crystallization core for discharging of the electrode material, so that dynamic obstruction in new phase formation can be lowered; and by virtue of zinc, the grain size of the new phase in the discharging process is reduced, so that process of a charging reverse reaction can be facilitated.

Description

technical field [0001] The invention relates to the technical field of a method for manufacturing a high-performance copper fluoride composite lithium battery cathode 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 by automo...

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Problems solved by technology

However, there are still very few reports on copper fluoride materials as cathode materials for lithium-ion batteries. The main difficulty is that the electrochemical properties of copper fluoride are closely related to the preparation process and have poor repeatability; at the same time, copper fluoride materials in organic electrolytes The medium stability is not enough; it also has a negative characteristic that the electronic conductivity is extremely low, so it will lead to a high polarization voltage during the charge and discharge process, although some researchers use carbon black mixed ball milling to improve the conductivity of the material However, it is still difficult for granular carbon black to form a complete conductive link, which greatly improves its electronic conductivity.

Finally, the material produces a new phase of metallic copper and lithium fluoride during discharge, and the small particles of the new phase are kinetically disadvantaged in the initial formation stage, so the maintenance of the subsequent charge-discharge capacity, discharge potential, and charge-discharge capacity ability to adversely affect

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