Composite cathode materials for next-generation lithium fluorinated carbon primary batteries

Currently, lithium fluorinated carbon (Li/CFx) primary batteries have been considered as one of the most promising electrochemical energy supply technologies in the military and medical fields, owing to multiple advantages including high energy density, low self-discharge rate, and good safety. Nevertheless, the intrinsic contradiction between capacity and conductivity of CFx materials together with special surface LiF passivation mechanisms during lithiation process, inevitably result in poor power density and severe voltage hysteresis. To address these problems, designing composite cathodes by integrating CFx with other materials (e.g. carbon, polymer, metal oxide, metal) is an effective solution. In this review, representative progresses of CFx materials are firstly introduced, accompanied with systematical analysis on key mechanisms and scientific issues. Subsequently, a series of CFx-based composite cathodes with unique characteristics and advantages are comprehensively discussed and compared. Finally, general design rules of composite cathodes are proposed based on clarifying the relationships between composition, structure, and performance. This review not only provides guideline for designing advanced CFx-based cathode materials, but also inspires further development of primary lithium batteries with superior energy density and power density.