SnS2 quantum dots-coated VO2@carbon nanorods for secondary battery displaying high capacity and rate-performance

Abstract

Electrode materials optimization is one of the keys to improving the energy storage characteristics of secondary batteries. Herein, a VO₂@carbon@SnS₂ composite is developed by coating SnS₂ quantum dots (QDs) on lamellar VO₂@carbon nanorods, yielding a high-performance aluminum-ion battery cathode. SnS₂ QDs embedded in VO₂@carbon accelerate electron transport, while the in situ coating of carbon improves cycling stability. When cycling at 0.5 A g⁻¹, capacity is maintained at 157.6 mA h g⁻¹ after 200 cycles. Even at 1.0 A g⁻¹, the cathode can be stably cycled 1000 times. Capacity remains at 176.3 mA h g⁻¹ and coulombic efficiency is 99.1% at temperatures below −10 °C after 100 cycles. These findings provide new ideas for the development of QD-modified composites for application in secondary batteries.