KCu7S4 nanowires and the Mn/KCu7S4 nanostructure for solid-state supercapacitors

Abstract

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.