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.