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

Abstract

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.