Molecular aggregation state and electrochemical performance of mesophase pitch fluoride

Abstract

Lithium/carbon fluoride batteries utilizing carbon fluoride as the cathode material have the highest energy density among primary batteries. However, the demanding synthesis conditions for carbon fluoride result in high-production costs, which hinders the widespread adoption of lithium/carbon fluoride batteries. Mesophase pitch fluoride, which exhibits microstructures similar to those of carbon fluoride, has the potential to be used as a low-cost cathode material. In this study, a facile low-temperature fluorination method was employed to synthesize a mesophase pitch fluoride with a high F/C ratio. Solvent-induced dipolar coupling was employed to segregate the mesophase pitch fluoride selectively into two distinct aggregated states with varying structures. When employed as a cathode material for lithium primary batteries, the ordered microcrystalline structure of the mesophase pitch fluoride exhibited a discharge capacity of 743 mA h g−1. Furthermore, it exhibited electrochemical behaviors that were distinguishable from those of conventional carbon fluoride materials. This study introduces a novel research perspective for exploring the viability of low-cost fluorinated pitches in the energy storage domain.