Promises and Challenges of Sn‐Based Anodes for Sodium‐Ion Batteries†

Abstract Sn‐based composites are considered as one of the promising anode materials for sodium‐ion batteries (SIBs) due to their high theoretical capacities and suitable operation voltages. However, they suffer the huge volume change and unstable electrolyte/electrode interface during sodiation/desodiation, which causes structure collapse and serious capacity loss. In the past few years, great efforts have been made to ameliorate the performances of Sn by rationally designing electrode structures/components or optimizing electrolyte composition. Here, the underlying sodium‐storage reactions in Sn are summarized based on the results from theoretical calculations and advanced characterizations. Then, the recent progresses of Sn‐based composites, i.e ., Sn‐based alloys, Sn/C composites, and Sn oxides/sulfides, with various structures for SIBs are discussed in details. After that, how the electrolyte affects solid‐electrolyte interphase and the electrochemical performances is shown. Finally, the future directions for the applications of Sn‐based composites in SIBs are suggested. Hence, this review provides a comprehensive scenario about the applications of Sn‐based composites in SIBs. It will benefit the future development of alloy‐type anodes in SIBs.