Conductive Carbon-Wrapped Fluorinated Hard Carbon Composite as High-Performance Cathode for Primary Lithium Batteries

Abstract

Lithium/carbon fluoride (Li/CFx) batteries have been widely researched due to their high theoretical specific energy. To create a high-performance electrode, the fluorinated hard carbon (FHC) is prepared by direct gas-phase fluorination. It has a high F/C ratio of 0.95 based on the gravimetric method. Selecting hard carbon (HC) with a high surface area as the carbon source allows for FHC to achieve suitable interlayer spacing and specific surface area, as well as abundant pore structures to facilitate rapid lithium ion transportation. Additionally, a composite of graphene and carbon nanotubes (CNTs) is coated on the surface of FHC, enhancing electron transport speed. The resulting FHC&C exhibits a very high energy density of 1256 Wh kg−1 and an excellent power density of 72,929 W kg−1 at a high rate of 40 C. Moreover, compared to commercial CFx, FHC&C exhibits higher energy and power densities, thus presenting a promising practical application prospect.