Abstract
Vanadium disulfide(VS2)as a typical two-di-mensional transition metal chalcogenide has excellent competitiveness for sodium-ion storage due to its wide layer spacing(0.575 nm),high theoretical capacity of 932 mAh·g-1 originating from multi-electron electrochemical redox.However,continuous sodiation process accompa-nied by crystal structural evolution and collapse cause rapid capacity decaying.Herein,novel few-layer VS2 nanosheets with open(001)crystal planes are in-situ constructed on reduced graphene oxide to solve these issues mentioned above.It indicates that few-layer VS2 provides more Na+storage activity due to the low Na+surface migration energy barrier on exposed crystal(001)planes.The flexible and high electronic conductivity of carbon matrix also effectively builds multi-level buffer structure and electron transport kinetics to boost the Na+insertion/conversion reactive activity on VS2 as well as Na+pseudocapacitance storage kinetics on edges and defects of nanosheets.Those coupling effects result in high rate capability and long cycling stability as a battery/ca-pacitor anode.It delivers conspicuous high energy density of 81 and 40 Wh·kg-1 at power density of 118 and 10,286 W·kg-1,as well as 80％energy retention rate after 5000 cycles,confirming its great application potential in sodium-based storage devices.
基金项目
National Natural Science Foundation of China(52072322)
National Natural Science Foundation of China(51604250)
Sichuan Science and Technology Program(2022YFG0294)
Sichuan Science and Technology Program(2019-GH02-00052-HZ)
NETL
NSTL
万方数据