Versatile metal fluorides in ion battery application

Abstract

With the increasing demand for energy storage devices with simultaneous high energy density, ultrahigh stability and superior security, it is of great practical significance to exploit and utilize novel electrode materials that can meet these requirements at the same time. Versatile metal fluorides with simultaneously high theoretical specific capacity and highest redox potential have entered the field of view. However, metal fluorides suffer from some serious defects, such as large voltage hysteresis, poor electron/ion conductivity and large volume change during their different applications. In this review, various cutting-edge metal fluorides applied as cathode materials and protective artificial interphase films in cationic batteries as well as solid electrolytes in anionic fluoride ion batteries are systematically summarized, mainly focusing on their advantages, disadvantages, and judicious improvement strategies, trying our best to provide a valuable reference on metal fluorides for readers and researchers.