Recent progress on FeS 2 as anodes for metal‐ion batteries

The ever-growing demand for advanced battery technologies with high energy and power density, high security, prolonged cycle life, and sustainably low cost requires the development of novel electrode materials for lithium-ion batteries (LIBs), as well as the alternative electrochemical energy storage technologies of sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs) for their abundant alkali metal elements resources. Among various anode materials, such as graphite, organic compounds, metal oxides, and chalcogenides, iron sulfides have attracted substantial interests for their high theoretical capacity and low price. Specifically, as a common mineral that has been already applied as electrode for primary battery, ferrous disulfide (FeS2) has been regarded as one of the promising candidate anode materials and studied widely. Unfortunately, there are some inherent problems handicapping its practical application for alkali-ion batteries, including limited ionic/electrical conductivity, the formation of soluble polysulfides, and large volume change. In the last decade, massive efforts have been devoted to solving those problems. In this review, the various synthesis strategies, the effect of morphologies and particle sizes, the energy storage mechanisms, and the electrochemical performances of FeS2 as anode for alkali-ion batteries (LIBs, SIBs, and PIBs) are summarized. Furthermore, the existing challenges and prospects of the development of FeS2-based anode materials for alkali-ion batteries are presented at last. In this review, the various synthesis strategies, the effect of morphologies and particle sizes, the energy storage mechanisms, and the electrochemical performances of FeS2 as anode for alkali-ion batteries are summarized. Furthermore, the existing challenges and prospects of the development of FeS2-based anode materials are also presented.