We report a novel pseudocapacitor based on KCu7S4 nanowires. To improve the electrochemical performance of the KCu7S4 capacitor, we changed the structure of the KCu7S4 nanowire electrode by coating Mn particles (Mn/KCu7S4). The preferable capacitance is shown by the Mn/KCu7S4 hybrid capacitor, which displays large specific capacitance (1620 F g−1) at a scan rate of 1 mV s−1, high energy density, good cyclic stability and three supercapacitor units in series light 400 light-emitting diodes (LEDs) for 2 min. The much-increased capacity, rate capability, and cycling stability may be attributed to the Mn/KCu7S4 hybrid structure, which enhances ionic and electronic transport through the electrode system.
