Continuous conductive liquid phase synthesized C/Cu/CuF2 composite copper fluoride lithium ion battery positive electrode material and preparation method thereof

Abstract

The invention relates to a continuous conductive liquid phase synthesized C/Cu/CuF2 composite copper fluoride lithium ion battery positive electrode material and a preparation method thereof. According to the method, side-reaction products such as various compound salts of copper fluoride in liquid phase reaction are prevented by designing a mixing mode of raw materials of copper sulfate pentahydrate and ammonium fluoride and an addition mode and addition rate of water; meanwhile, a high-conductivity continuous carbon film with a hole and gap structure is formed by the drying process under a low-temperature and high-vacuum condition and the subsequent thermal treatment process, and the electron conductivity of a composite material is substantially improved; and moreover, a certain amount of copper is reduced on surface of copper fluoride particles in an in-situ way, a homogeneous crystal core is provided for an electrode material during discharging, dynamics blocking formed by a new phase is reduced, and the capacity of the material, the cycle capacity stability and a potential of a discharge platform are improved.

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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