▎ 摘　　要

Self-supported NiSe2 nanospheres have been successfully synthesized by a one-step microwave method, and then coated with a layer of reduced graphene oxide (rGO) by a simple dip-coating method. Due to the excellent conductivity and high surface area of rGO, as a battery-type electrode material, the as-prepared NiSe2@rGO composite exhibited an excellent specific capacity of 224.75 mAh g(-1) at 1 A g(-1), far exceeding that of the NiSe2 nanospheres (72.5 mAh g(-1) at 1 A g(-1)). NiSe2@rGO showed good cycling performance, with 78.13% retention of its initial capacity after 5000 cycles. Furthermore, an NiSe2@rGO//activated carbon (AC) asymmetric supercapacitor (ASC) showed a high energy density (E) of 25.85 Wh kg(-1) at a power density (P) of 730 W kg(-1). The NiSe2@rGO//AC showed good capacity retention, maintaining 85.45% of the original value after 10000 cycles.