Construction of Cu4SnS4/CuS@C nanorods with high initial coulombic efficiency for lithium-ion batteries

Sn-based chalcogenides have garnered widespread attention as an alternative anode for lithium-ion storage, attributed to the combined features of large layer space, high theoretical specific capacity, and abundant resources. However, the sluggish kinetics, serious volume expansion during the alloying reaction and low initial Coulombic efficiency (ICE) severely impair the rate capability and cyclic life. In response, we employ a synergistic effect of multiple element introduction and carbon matrix to construct a novel Cu4SnS4/CuS@C anode. The carbon layer renders the anode fast electron/ion transfer and curbs the volume expansion. Meanwhile, the formation of Cu mitigates the aggregation of Sn particles during the lithiation process, thus improving the ICE. Consequently, the intricate structure of Cu4SnS4/CuS@C endows the anode with impressive rate capability and cyclic stability, achieving 600.52 mAh g- 1 at 1 A g- 1 (300 cycles), much superior to that of SnS@C (faded to 154.53 mAh g-1). In addition, the Cu4SnS4/CuS@C anode reaches a high ICE (91.36 %), surpassing most reported Sn-based anodes. This work provides valuable insights for developing advanced anodes with high ICE, outstanding rate capability and reversibility for the next-generation LIBs.