MOF‐74‐Derived Fe 7 S 8 @C Composites as High‐Performance Anodes for Sodium‐Ion Batteries

ABSTRACT Fe 7 S 8 @C composites have been synthesized by employing Zn/Fe‐MOF‐74 as a sacrificial template and followed by sulfurization treatment. Fe 7 S 8 @C composites exhibit a dual morphology, comprising spindle‐like frameworks with secondary submicron particles dispersed throughout. When applied as a sodium‐ion battery (SIB) anode, the Fe 7 S 8 @C composites exhibit superior electrochemical properties with superior rate performance and extraordinary cyclical stability, achieving a reversible specific capacity of 333 mAh g −1 at 5 A g −1 upon 2000 cycles. The excellent electrochemical performance of the Fe 7 S 8 @C composite arises from the synergistic effects of its distinctive architecture, in which Fe 7 S 8 is responsible for providing a high capacity, and homogeneously distributed Fe 7 S 8 nanocrystals confined within the porous carbon framework collectively suppress particle agglomeration, promote fast charge transfer kinetics, and guarantee optimal electrolyte accessibility. It is encouraging that our synthetic strategy can be extended to prepare various metal sulfide@carbon composites as superior anode materials for SIBs.