Core–shell carbon fiber@Co1.5Mn1.5O4 mesoporous spinel electrode for high performance symmetrical supercapacitors

Abstract

We report a mesoporous composite system consisting of carbon fiber cores surrounded with Co1.5Mn1.5O4 spinel nanocrystal shells, synthesized by a simple two–step process involving single–nozzle co–electrospinning and subsequent calcination. Benefiting from the obtained core–shell structure, this composite has exhibited high specific capacitance in the two–electrode configuration, up to 384 F g−1 at 0.28 A g−1, with no capacitance loss after 2000 cycles at 50 mV s−1. The incorporation of spinel nanocrystals improved the capacitive performances of composite fibers due to a synergistic effect of redox–active shells and the conductive cores, making this novel material promising for symmetrical supercapacitors.