Hierarchical WO@MnWO core-shell structure for asymmetric supercapacitor with ultrahigh cycling performance at low temperature.

In this work, for the first time we report a kind of novel WO@MnWO core-shell structure prepared by a facile and cost-effective solution route. The core-shell structure consists of WO nanowire array as the core and MnWO nanosheets as the shell. The as-synthesized hybrid structures as the supercapacitor negative electrodes possess remarkably enhanced specific capacitance. By matching with MnO nanosheets as the positive electrode, a 2 V voltage asymmetric supercapacitor is assembled, which reveals an excellent rate capability with 92.11% capacity retention after 10,000 cycles. In addition, the as-obtained ASC presents outstanding cycling performance after 10,000 cycles at the working temperature of 3 °C.