Facile Fabrication of NiCo₂O₄@g-C₃N₄(C) Hybrids for High-Performance Supercapacitors

The rational design and synthesis of electrode materials with large specific capacitance and good cycling stability have gained tremendous attention but remained as a challenge. Herein, NiCo₂O₄@g-C₃N₄(C) hybrid was synthesized by growing spinel nickel cobaltite (NiCo₂O₄) on the carbon doped graphitic carbon nitride (g-C₃N₄(C)). The elegant synergy between NiCo₂O₄ and g-C₃N₄(C) leads to a high specific capacitance of 325.7 F·g^-1 at the current density of 1 A·g^-1 and an exceptional cycling stability (93.6% retention after 2000 cycles). NiCo₂O₄@g-C₃N₄(C) hybrid asymmetric capacitor was assembled and electrochemical tests showed that asymmetric capacitor possesses high power density (15.1 kW·kg^-1) and superior cycling stability (83.5% retention after 2000 cycles).