Carbon intermediate boosted Fe–ZIF derived α–Fe2O3 as a high-performance negative electrode for supercapacitors

Abstract

Earth-abundant Fe2O3 is a promising material for the negative electrode of supercapacitors by virtue of its wide potential windows. However, the unsatisfactory electrical conductivity and poor ionic diffusion rate within Fe2O3 results in degraded electrochemical performance. In this work, to address these issues, we demonstrate an easy method to synthesize Fe-based zeolitic imidazolate framework (Fe–ZIF) derived α–Fe2O3@C with remarkable supercapacitive properties. The as-obtained α–Fe2O3@C electrode, with the particular benefit of dispersed distribution of carbon, enabling fast electrochemical response, presents a prospective specific capacitance of 161 Fg−1 at a current density of 1 Ag−1. Furthermore, by using the α–Fe2O3@C architecture as the negative electrode, we fabricated a supercapacitor with Na0.5MnO2 as the positive electrode. Our supercapacitor shows a high energy density of 25 Whkg−1, while the corresponding power density is 2400 Wkg−1 at a current density of 2 Ag−1.