Boost VS 2 electrochemical reactive kinetics by regulating crystallographic planes and coupling carbon matrix for high performance sodium‐ion storage

Abstract Vanadium disulfide (VS 2 ) as a typical two‐dimensional 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 accompanied by crystal structural evolution and collapse cause rapid capacity decaying. Herein, novel few‐layer VS 2 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 VS 2 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 VS 2 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/capacitor 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.