Architectural Ni3Se2 nanosheet-on-nanoforests as free-standing electrodes for high-performance hybrid supercapacitors

A unique electrode architecture consisting of Ni3Se2 nanosheet-on-Ni3Se2-nanoforests grown on nickel foam was obtained by a simple one-step solvothermal method, which subsequently used as a free-standing electrode for supercapacitor. The Ni3Se2 exhibited a high capacity of up to 600 μAh cm−2 at 3 mA cm−2, excellent rate capability and cycling stability at high cycling rates. Impressively, the optimized hybrid supercapacitor containing Ni3Se2 cathode still released 94.4% of initial capacity for 505 μAh cm−2 after 6000 cycles at 20 mA cm−2. The results suggest that the Ni3Se2 nanoforests developed electrode has great potential for practical applications in hybrid supercapacitors.