Rationally designed carbon coated ZnSnS3 nano cubes as high-performance anode for advanced sodium-ion batteries

Highlights: • ZnSnS₃ is introduced as high-performance anode for sodium-ion batteries. • Nanoscale carbon coating greatly improves the cycling stability of ZnSnS₃. • ZnSnS₃@C NCs deliver a capacity of 661.4 mAh g⁻¹ at the 250th cycle. • ZnSnS₃@C NCs demonstrate excellent cycling stability and rate performance. Metal sulfides have gradually gained attention as preferable anode materials in sodium-ion batteries (SIBs) due to their high theoretical capacities. In this work, we report for the first time the synthesis of carbon coated ZnSnS₃ nanocubes (ZnSnS₃@C NCs) as high-performance anode material for SIBs. The outer carbon coating surrounding the ZnSnS₃ active material not only enhances the electronic conductivity of the anode but also increases the electrode reaction active sites. Thus, it can greatly improve the reversible capacity as well as homogenize the repeated volume changes of the active material and decrease the mechanical stress caused during the prolonged charge/discharge process, which could finally enable an enhanced electrode stability. Electrochemical test results demonstrated that the introduced ZnSnS₃@C NC anode is capable of delivering a high reversible capacity of 661.4 mAh g⁻¹ at a current density of 100 mA g⁻¹ after 250 cycles (with capacity retention of 97.1%) and demonstrating a stable Coulombic efficiency of over 99%. To the best of our knowledge, both the reversible capacity and cycling stability performance introduced in this work are so far the best among metallic sulfur-based anodes and are even superior to some recently reported SnS₂-based anodes.