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

In this study, a mechanochemical method was used to synthesize the alpha- and beta-phases of CoMoO4, and the performances of the synthesized CoMoO4 for energy storage applications were studied. Among the synthesized samples, beta-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 beta-CoMoO4//AC prepared with beta-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.