A facile way to grow NiMn-LDH sheets on KCu7S4 nanowires with synergistic effects for applications in hybrid supercapacitors

A facile way to grow NiMn-LDH sheets on nano-sized KCu7S4 wires through simply stirring and heating was conducted in this work. The morphology evolutions and growth mechanisms were revealed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Interestingly, the as-prepared KCu7S4@LDH showed synergistic effects for electrochemical energy storage performance through combining the advantages of NiMn-LDH and KCu7S4. As a result, it showed an improved specific capacitance of 1833 F g−1 at the current density of 1 A g−1, superior to individual NiMn-LDH or KCu7S4. Besides, hybrid supercapacitors using KCu7S4@LDH as positive electrodes were constructed. The cell exhibited a high energy density of 33 Wh kg−1 at a power density of 394 W kg−1 and a superior cycle life of 82.5% retention after 6000 cycles.