CuCoNi-S anchored CoMoO₄/MoO₃ forming core-shell structure for high-performance asymmetric supercapacitors

Although the preparation of transition metal sulfides/oxides electrodes has been relatively perfected, it is still challenging to fabricate multi-component transition metal sulfides/oxides core-shell structure electrodes with excellent electrochemical performance. Herein, CoMoO₄/MoO₃@CuCoNi-S grown on nickel foam (NF) is first synthesized via facile hydrothermal and electrodeposition methods. The CoMoO₄/MoO₃@CuCoNi-S electrode presents an exceptional specific capacitance (2600.0 F g^-1 at 1 A g^-1) and 68.3% of its initial capacitance at 10 A g^-1. Moreover, a CoMoO₄/MoO₃@CuCoNi-S//active carbon (AC) device is assembled for determining its electrochemical application. It reveals a high energy density of 42.1 W h kg^-1 at a power density of 800.2 W kg^-1, an extended voltage window of 1.6 V and excellent stability with 96.9% retention after 5000 cycles at 2 A g^-1. This work offers a reference case for the development of multi-component transition metal sulfides/oxides core-shell structure composites for energy storage.