Molybdenum and sulfur co-doped CoNiO2 with tremella-like nano-structures as electrode material for high-performance supercapacitors

Heteroatomic doping has a significant effect on improving the electrochemical energy storage of metal oxide electrode materials and has been applied in the field of supercapacitors. However, there are few reports on the co-doping of anions and cations into transition metal oxides as the electrode materials in supercapacitors. Herein, the Mo, S co-doped CoNiO2 electrode material with tremella-like nano-structures was successfully prepared on nickel foam (denoted as [email protected]) via two-step hydrothermal procedures and UV-light irradiation. The co-doping of Mo and S gives the CoNiO2 material a higher specific surface area of 113.98 m2 g−1, abundant active site, and improved electrical conductivity. The obtained [email protected] shows a high specific capacity of 999.1C g−1 at a current density of 1 A g−1. Moreover, the hybrid supercapacitor device assembled by [email protected] and [email protected] can obtain a great energy density of 38.8 Wh kg−1 at a power density of 2880 W kg−1 and shows good cycling stability of 71.6 % capacity retention after 6500 cycles, indicating the excellent supercapacitive properties of [email protected] and its potential application in supercapacitors.