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

Abstract Pyrite (FeS 2 ), 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 FeS 2 in liquid secondary batteries limit its further development. Solid‐state batteries offer effective solutions to these challenges. In this review, the synthesis methods of FeS 2 and recent progress in FeS 2 ‐based solid‐state lithium/sodium batteries are presented, and the effects of FeS 2 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 FeS 2 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 FeS 2 and promote further development of FeS 2 in electrochemical energy storage.