Method for modifying carbon fluoride positive electrode material by using chromium oxide or chromium oxide compound

Abstract

The invention discloses a method for modifying a carbon fluoride positive electrode material by using a chromium oxide or a chromium oxide compound, which comprises the following steps of: (1) adding CrO3 and carbon fluoride into absolute ethyl alcohol, and performing high-energy ball milling to form mixed slurry; (2) drying the mixed slurry and sieving the dried mixed slurry with a 100-200-mesh sieve to obtain mixed powder; (3) putting the mixed powder in an air atmosphere furnace, and heating the mixed powder to 196-240 DEG C to obtain a molten-state mixture; and (4) stirring the molten-state mixture for 2 hours to fully and uniformly mix the carbon fluoride and the molten-state CrO3, heating and calcining the mixture, taking out a product, cooling and grinding the product, and sieving with a 100-200-mesh sieve to obtain the carbon fluoride positive electrode material modified by the chromium oxide or the chromium oxide compound. According to the obtained material, the problem of voltage lag at the initial stage of discharge is effectively solved, the rate capability and platform voltage of a lithium carbon fluoride battery are improved, the temperature rise of the lithium carbon fluoride battery in the discharge process is reduced, and the preparation method is simple and low in cost.

Description

technical field [0001] The invention belongs to the technical field of lithium battery materials, and in particular relates to a method for modifying fluorinated carbon positive electrode materials by using chromium oxide or a compound thereof. Background technique [0002] Low-cost and high-power primary batteries are indispensable for various daily electrical appliances. Lithium primary batteries are easy to store, stable discharge performance, high energy density, easy to be composed by series and parallel designs, and suitable for extreme conditions such as high temperature and high pressure. Battery packs for various scenarios still have research and development value. Among them, lithium carbon fluoride primary batteries have many advantages: (1) The discharge voltage platform is high and wide: the maximum voltage of other dry batteries such as zinc-manganese batteries can only reach below 1.5V, while the maximum voltage of Li / CFx primary batteries can reach above 3V; ...

AI Technical Summary

Problems solved by technology

However, lithium / carbon fluoride batteries have the following disadvantages: (1) In the initial stage of battery discharge, there is a voltage delay; (2) High and low temperature performance decays; (3) A large amount of heat is generated as the discharge progresses; (4) When discharging at a high rate , the specific capacity decays rapidly

[0007] However, due to the use of solvents such as caustic soda and other corrosive equipment, and many limiting factors, the modification method of carbon fluoride cathode materials has complicated steps, many control requirements, or problems such as voltage hysteresis and insignificant improvement in rate performance, which seriously restrict Li The development of carbon fluoride batteries, so solving the rate performance of lithium carbon fluoride batteries and heat generation during discharge is an urgent task for the development of carbon fluoride lithium batteries

This application is based on the previous CN110783522B "Preparation method of nano-material modified carbon fluoride electrode material", CN109659515A "Preparation method of Ag@C modified carbon fluoride electrode material" and other bases on the surface modification of carbon fluoride In-depth exploration, although the problems of voltage hysteresis and low rate performance have been greatly overcome in the previous research results, the large heat release of carbon fluoride batteries has not been effectively solved. Fluorinated carbon hysteresis, greatly improved high-rate performance, and able to overcome the adverse conditions such as quality degradation and service life reduction caused by a large amount of heat during the discharge process are particularly important.

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