LAUSR

Developing novel electrode materials with reasonable structures and ideal conductivity is of great significance for energy storage devices. In this work, Ni3Se2@C yolk-shell nanorods are grown on nickel foam (NF) via a one-step selenization and carbonization process. The carbon shell not only improves the conductivity and charge transfer of electrodes, but also inhibits the dissociation of Ni3Se2 core during redox reactions, which is crucial to electrochemical performances of SCs. Owing to the yolk-shell nanorod structure, the Ni3Se2@C electrode exhibits an outstanding specific capacitance of 1669.7F g-1 at 1 A g-1. Moreover, an asymmetric supercapacitor (ASC) is successfully assembled using Ni3Se2@C and active carbon (AC) electrodes as the anode and cathode respectively, which delivers remarkable energy-storage characteristics. Specifically, the Ni3Se2@C//AC ASC shows a high energy density (31.0 Wh kg-1) at a power density (723.7 W kg-1), and stable cycling performance (97% capacitance retention after 9000 cycles). These results make the Ni3Se2@C a promising electrode for SCs.