Plasma-enhanced fluorination of layered carbon precursors for high-performance CFx cathode materials

Abstract

Lithium/fluorinated carbon (Li/CFx) primary batteries employed in commercial, medical, and military fields, are still hindered by the poor rate performance, which is closely related to the fluorination process and precursor carbon materials. Herein, we reported an eco-friendly, simple and efficient fluorination strategy, namely, plasma-enhanced fluorination (PEF), to manufacture plasma fluorinated expanded graphite (PFEG) and plasma fluorinated graphene (PFG). Chemically similar PFEG and PFG materials were also constructed to study the effect of morphology and microstructure of the carbon precursors on the PEF process and the resulting CFx materials’ electrochemical performance. The Li/PFG coin cell exhibits excellent rate performance with a high specific capacity of 838.3 mAh/g at a high current density of 10 A/g. The pouch cell based on the PEF pilot reactor delivers a specific capacity 771.4 mAh/g at 0.1 A/g, confirming the potential of PEF for scalable production of high-quality (high energy density and high-power density) CFx cathode materials. These findings will greatly contribute to the research and development of Li/CFx primary batteries in the way of optimizing carbon precursors and developing new fluorination strategies.