Enhanced cycle performance of ultraflexible asymmetric supercapacitors based on a hierarchical MnO2@NiMoO4 core-shell nanostructure and porous carbon

A one dimensional core-shell hierarchical MnO2@NiMoO4 nanostructure is rationally designed and prepared by a facile two-step hydrothermal method. This hybrid, along with porous carbon, is employed as an active material to fabricate flexible asymmetric supercapacitors, exhibiting a high capacitance of 186.8 F g(-1) at a scan rate of 10 mV s(-1), super-long cycling life with a 132.7% retention rate after 20 000 cycles, and super flexibility with no obvious changes of specific capacitance after bending to 30 degrees to 150 degrees (the corresponding radius of curvature is 4.5 mm to as small as 1.0 mm). Moreover, the supercapacitor is fabricated into a power system, in combination with a solar cell, to successfully supply electricity to light emitting diodes, showing its practical applications in portable energy storage devices.