Fluorinated Pyrocarbon Prepared from Ketjenblack for Primary Lithium Battery

Abstract

Pyrocarbons were obtained by heat-treatment of Ketjenblack at different temperature from 1000°C to 2400°C, and fluorinated in NF3atmosphere at 520°C to give CFxsamples with high fluorine content. The results indicate that the structure of both pyrocarbons and their derivative fluorides mainly depend on the heat-treatment temperature of raw carbon. The correlation between the electrochemical performance and the structure of pyrocarbon fluoride was discussed in detail. At an optimum condition, the yield of fluorination can come up to 90%, and the pyrocarbon fluoride, as cathode active material of lithium primary cell, gives an energy density up to 2200 Wh kg-1.