The rational design of Fe2O3@MnO2 derived from Fe[Fe(CN)6]∙4H2O as negative electrode for asymmetric supercapacitor

Abstract

Metal–organic frameworks (MOF)-derived nanomaterial have shown great promise as a supercapacitor anode materials. In this work, we successfully synthesized a novel Fe2O3@MnO2 composite with core–shell by hydrothermal techniques. MnO2 nanorods decorated on the Fe2O3 nanoparticles which was direct pyrolysis of Fe-PBA can combine of advantages of Fe2O3 and evenly dispersed MnO2 to obtain an ultra-wide voltage window of −1.1 V - 0.4 V and an excellent specific capacitance of 449 F g−1. The further constructed NiCo-LDH/rGO//Fe2O3@MnO2 asymmetric supercapacitor achieves a high energy density of 33.4 Wh kg−1 at a high power density of 800 W kg−1 and a capacity retention of more than 75 % after 10,000 cycle tests. This study not only corroborates the considerable potential of Fe2O3@MnO2 as anode material for supercapacitors, but also offers a novel approach to the design of asymmetric supercapacitors, which will facilitate the advancement of supercapacitor technology towards higher energy density and longer lifetime.