Continuous conducive in-situ C/metal solid solution/Ce<4+>-doped CuF<2> positive electrode and preparation method

Abstract

The invention discloses a continuous conducive in-situ C / metal solid solution / Ce<4+>-doped CuF<2> composite copper fluoride lithium ion battery positive electrode material and a preparation method therefor. According to the preparation method, by means of a drying process in a low-temperature and high-vacuum condition and a carbonization and in-situ reduction process under gas protection, a continuous carbon film with holes and a gap structure can be formed; copper fluoride is fixedly formed on the carbon film, and the metal solid solution is subjected to in-situ reduction on the surface of copper fluoride granules in an in-situ manner, so that electronic conductivity of the composite material is greatly improved; a homogeneous crystallization core can be provided for discharging of the electrode material and dynamic obstruction in new phase formation can be lowered; by virtue of Ce<4+> doping, the rate of a discharging reaction can be improved; and meanwhile, generation of multiple kinds of compound salt of copper fluoride and other secondary reaction products in a liquid phase reaction can be avoided, and excellent electrochemical performance is achieved.

Description

technical field [0001] The invention relates to the technical field of a method for manufacturing a high-performance copper fluoride 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 automobile exhau...

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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

Ion doping is also an effective way to adjust the microstructure of the lattice and change the electron and ion transport characteristics of the lattice. However, the mechanism of ion doping or even multi-ion synergistic doping on the matrix is ​​very complicated, and the effect is often difficult. expected

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