Pyrite-Based Solid-State Batteries: Progresses, Challenges, and Perspectives

Pyrite (FeS₂), as a transition metal sulfide, has a promise application in the field of secondary batteries due to its abundant reserves, high theoretical capacity, safety, and non-toxicity. However, serious volume expansion and shuttle effect of FeS₂ in liquid secondary batteries limit its further development. Solid-state batteries offer effective solutions to these challenges. In this review, the synthesis methods of FeS₂ and recent progress in FeS₂-based solid-state lithium/sodium batteries are presented, and the effects of FeS₂ size and morphology, solid electrolyte type, and battery structure design on the electrochemical performance of solid-state batteries are discussed. By analyzing and summarizing the problems in applying FeS₂ in solid-state batteries, the remaining challenges in this field are discussed and future directions are proposed. This review aims to guide research on high-performance solid-state batteries based on FeS₂ and promote further development of FeS₂ in electrochemical energy storage.