Progress of FeP anode materials for alkali metal ion batteries

FeP is a promising insertion-conversion electrode material. It has been demonstrated that this material exhibits several noteworthy physicochemical properties, including a high theoretical capacity, low cost, and good mechanical and thermal stability. Furthermore, its low insertion potential and high theoretical capacity of up to 926 mA h g^-1 have attracted the attention of researchers as a potential electrode material for alkali metal ion batteries (AMIB). However, the material also exhibits certain disadvantages, including a considerable voltage hysteresis, a substantial volume change, and suboptimal reaction kinetics, resulting in a relatively low-rate capacity and accelerated capacity decay. However, some effective strategies such as composite, doping, and nanostructuring have shown promising applications. Here we present a timely and systematic review of the latest research and significant advances in FeP and its composites, covering synthesis, electrode design, and applications (especially in advanced lithium/sodium/potassium ion batteries) and their reaction mechanisms. Consequently, further modifications have been devised for using iron phosphide composites as anode materials for alkali metal ion batteries (AMIB). The continued innovation of FeP-based anodes demonstrates promise for their utilization in large-scale energy storage applications, including grid storage and electric vehicles. Furthermore, there is an aspiration to encourage the ongoing advancement of FeP anode materials for the development of advanced rechargeable ion batteries.