Preparation and electrochemical properties of mesoporous Co3O4 crater-like microspheres as supercapacitor electrode materials

Mesoporous Co3O4 microspheres with unique crater-like morphology were obtained by utilizing the mesoporous silica material MCM-41 as a template. The analysis results of N2 adsorption–desorption measurement indicate that the product has a large Brunauer–Emmett–Teller (BET) surface area of 60 m2 g−1 and a narrow pore size distribution centering around 3.7 nm. Its electrochemical properties were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements. The findings reveal that this novel morphology material has a smaller inner resistance of about 0.4 Ω and a higher onset frequency of 550 Hz. This material can provide a high specific capacitance of 102 F g−1 and a large capacity retention of 74% in 500 continuous cycles test at a sweep rate of 3 mV s−1. More significantly, the mass loading of electroactive species can reach as large as 2 mg cm−2, which is one order of magnitude larger than common amount used.