Flexible heterostructured supercapacitor electrodes based on α-Fe2O3 nanosheets with excellent electrochemical performances

Abstract

In this paper, two kinds of hybrid α-Fe₂O₃@Co₃O₄ and α-Fe₂O₃@MnCo₂O₄ composites with high yield have been successfully synthesized on a flexible carbon cloth via simple solution methods. These as-obtained products serve as supercapacitor electrodes without the use of any adscititious surfactants and binders. These two hybrid electrode architectures make full use of the synergistic effects between α-Fe₂O₃ frameworks and coated Co₃O₄ or MnCo₂O₄ layers. They exhibit obviously enhanced discharge areal capacitance of 490 mF cm⁻² and 1073 mF cm⁻² for α-Fe₂O₃@Co₃O₄ and α-Fe₂O₃@MnCo₂O₄ composites at 1 mA cm⁻² with an identical potential voltage of 0–0.9 V. Long-life cycling stability with capacitance retention of 74.6% for α-Fe₂O₃@Co₃O₄ and 77.8% for α-Fe₂O₃@MnCo₂O₄ are presented after 6000 charge/discharge cycles, respectively. Such prominent electrochemical performances are mainly ascribed to the hybrid composites, which can provide a large reaction surface area, fast ion and electron transfer and good structure combination stability. The as-synthesized flexible hybrid composites might have promising applications in micro/nanoscale energy storage devices.