Method for coating CFx

Abstract

The invention relates to a method for coating CFx. The method comprises the following steps: step 1, preparation of a carbon precursor: (1) adding humic acid or sulfonated asphalt into a LiOH solution to obtain an alkali solution free of solids; (2) adjusting the alkali solution with diluted hydrochloric acid to separate out solids to obtain solid weak-acid water-solubility nano carbon precursor ACM or SCP; and (3) preparing ACM or SCP and the LiOH solution into an ACM or SCP alkali aqueous solution; and step 2, the coating process of CFx powder: mixing the ACM or SCP alkali aqueous solution with CFx suspension to obtain mixed liquid, evaporating to obtain mixed solids, drying, cooling, sieving and carbonizing, thus finishing the coating process of CFx. According to the method, since a cheap water-solubility nano carbon material is used as a precursor, the uniformity of a carbon layer in the coating process can be ensured, the problem of voltage delay can be eliminated, and the conductivity, discharge voltage platform and rate performance of CFx can be improved.

Description

technical field [0001] The invention belongs to the technical field of cathode materials for lithium primary batteries, and in particular relates to a coating method of fluorinated graphite. Background technique [0002] Graphite fluoride [CF x ] Due to the advantages of high specific energy, high operating voltage, long storage time and wide operating temperature range, it can be used as a positive electrode active material to improve the capacity of lithium primary batteries, and has become a research hotspot in lithium primary battery cathode materials. Lithium / graphite fluoride [Li / CF x ] The battery is also a solid positive lithium battery that is first used as a commodity, and can be made into a series of coin-type, cylindrical and needle-bar structure batteries. Its theoretical mass specific energy is about 2180Wh / kg, and its working voltage is 2.5-2.7V. Graphite fluoride CF x It is a graphite intercalation compound generated by the direct reaction of fluorine and...

AI Technical Summary

Problems solved by technology

Although the above-mentioned methods have solved the problems of voltage hysteresis and poor rate performance to varying degrees, they have their own shortcomings, such as: the joint heating method of the mixture is usually not uniformly coated; the thermal condensation polymerization method needs to consume more energy and organic solvents; The raw materials of the resin coating method are relatively expensive and the cost is too high; the organic substances used in the organic solvent impregnation coating method are likely to cause environmental pollution; the equipment of the vapor deposition method is relatively complicated and is not suitable for mass production, and the organic vapor used is mostly toxic substances. It can also form an explosive mixture with air, and it is easy to burn and explode when exposed to open flames and high heat, resulting in dangerous and difficult operations.

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