Green preparation of CoMoO4 nanoparticles through a mechanochemical method for energy storage applications

Abstract

In this study, a mechanochemical method was used to synthesize the α- and β-phases of CoMoO₄, and the performances of the synthesized CoMoO₄ for energy storage applications were studied. Among the synthesized samples, β-CoMoO₄ nanoparticles showed a high specific capacitance/capacity of 182.6 F g⁻¹ (73.0 C g⁻¹) at a current density of 1 A g⁻¹ owing to their large specific surface area. After 8000 cycles, a capacitance retention rate of approximately 86.3% was achieved. The asymmetric supercapacitor β-CoMoO₄//AC prepared with β-CoMoO₄ as the positive electrode and activated carbon as the negative electrode exhibited a specific energy density of 8.66 W h kg⁻¹ at a power density of 755 W kg⁻¹. Additionally, the effects of the ball-milling speed on the electrochemical performance of the samples calcined at different temperatures were intensively studied. This work highlights the green, facile, and low-cost features of the mechanochemical method for the preparation of bimetal oxides, providing a reference for the mechanochemical synthesis of other new materials.