Cubic Cu3SnS4@CNT for stable and high-temperature sodium-ion batteries: Simple colloidal synthesis and enhanced cycle performance

초록

Transition metal sulfides are considered efficient sodium ion storage materials due to their high theoretical capacity and abundant redox sites. However, initial capacity drop and poor cycle performance issues arise because of volume expansion and structural degradation during the sodiation/desodiation process. Herein, bimetallic sulfides hybrid comprising of nano cubic Cu3SnS4 anchored on multi-walled carbon nanotube (Cu3SnS4@CNT) is constructed, enhancing sodium-ion storage. Cu3SnS4@CNT was prepared using a simple one- pot colloidal synthesis and evaluated as an anode material for SIBs, exhibiting a high specific capacity and robust cycle stability (461.4 mAhg-1 at 0.5 Ag-1 after 200 cycles, and 405.8 mAhg-1 at 1.0 Ag-1 after 900 cycles). The enhanced cycle performance was analyzed through capacitive contribution and overpotential using a galvanostatic intermittent titration technique. Cu3SnS4@CNT also operates at high temperature, showing excellent cycling stability (520.3 and 523.9 mAhg-1 at 1.0 Ag-1 after 100 cycles at 50 and 70 degrees C).

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