Pseudocapacitive materials are promising to increase specific capacity of carbon-based electrodes, but suffer from poor rate capability. In the work, novel Li:CuO/reduced graphene oxide flexible electrodes demonstrate enhanced electrical conductivity and specific capacitance obtained via the incorporation of Li into CuO particles. The degree of capacitance enhancement increases with scan rate, reaching a maximum value of 40% at a high scan rate of 500 mV/s. Galvanostatic charge/discharge measurements show high volumetric capacitance, energy density, and power density. Cyclic life tests show excellent stability over 10,000 cycles, with a capacitance retention of 93.2% at a scan rate of 100 mV/s.