Reviewing metal fluorides as the cathode materials for high performance Li batteries

Exploring high‐energy density rechargeable lithium (Li) batteries is urgently needed to meet the demand of the large‐scale electric vehicle market. Conversion‐type metal fluorides (MFx) have been considered as desirable cathode materials for next‐generation rechargeable batteries because of their high operational voltages, environmental non‐toxicity, low cost, and high thermal stability. In this review, we present the most promising and feasible MFx applied in rechargeable Li batteries in terms of capacity, discharge potential, volume change, fabricated methods, crystal structure, and cost/abundance. The electrochemical performance is briefly illustrated, and the recent advances in mechanisms focused on MFx cathodes upon cyclic processes are noted and discussed in detail. Finally, prospects for the current challenges and possible research directions, with the aim to provide some inspiration for the development of MFx‐based cathodes are presented.