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. [ABSTRACT FROM AUTHOR]