A novel synthesis of coral-like Co3O4 nanowires cluster for all-solid-state asymmetric supercapacitors

The coral-like Co3O4 nanowires (CNWs) cluster was synthesized by a novel strategy, in which polyurethane (PU) prepolymer was used as soft template during solvothermal process. The diameters of CNWs samples gradually decreased with the increasing of PU prepolymer. Electrochemical measurements showed that the CNWs possessed the largest specific capacitance of 502.6 F g−1, which is 2.2 times higher than that of bulk Co3O4. Moreover, an all-solid-state asymmetric supercapacitor based on CNWs as positive electrode and activated carbon as negative electrode delivered a high energy density of 18.3 Wh kg−1 and good cycling stability.