Porous α-Fe2O3 Hollow Rods/Reduced Graphene Oxide Composites Templated by MoO3 Nanobelts for High-Performance Supercapacitor Applications

Abstract

Porous α-Fe2O3 hollow rods/reduced graphene oxide (α-Fe2O3 HR/RGO) composites with unique morphological characteristics and a high surface area are prepared through a template strategy, which was systematically studied and found to have outstanding supercapacitive properties. When served as active material in a three-electrode setup, the optimized α-Fe2O3 HR/RGO-30, comprised 76.5 wt% α-Fe2O3 and 23.2 wt% RGO, was able to offer the largest specific capacitance of 426.3 F g−1, an excellent rate capability as well as satisfactory cycle life with capacitance retention of 87.7% and Coulombic efficiency of 98.9% after continuously charging/discharging at 10 A g−1 for beyond 10,000 cycles. Such electrochemical behaviors of the α-Fe2O3 HR/RGO-30 electrode can rival or even surpass those of many Fe2O3-based electrodes documented in the previous literature. Later, a symmetric supercapacitor cell of α-Fe2O3 HR/RGO-30//α-Fe2O3 HR/RGO-30 was fabricated. The assembled device offers the maximum energy density of 18.7 Wh kg−1, and also exhibits commendable rate capability, and features stable cycling durability (with capacitance retention of 83.2% together with a Coulombic efficiency of 99.3% after 10,000-cycle charge/discharge at 5 A g−1). These notable electrochemical performances enable the α-Fe2O3 HR/RGO-30 composite to be a high-potential material for advanced energy storage systems.

Flexible Asymmetric Supercapacitors Constructed by Reduced Graphene Oxide/MoO₃ and MnO₂ Electrochemically Deposited on Carbon Cloth

“…Supercapacitors (SCs) are potential energy storage devices and have been extensively studied owing to their characteristics such as high energy density, fast charge/discharge rates and long cyclic life [1,2]. They have been widely applied in hybrid electric vehicles, backup energy systems and mobile electronic devices, etc.…”

“…A flexible electrode of CC/MoS2/PANI has been prepared via combining the facile hydrothermal method and in situ polymerization method, the PANI of this electrode shows a Cs value of 972 F g -1 at a current density of 1 A g -1 which is significantly higher than that of CC/MoS2 (425 F g -1 ) [18]. 2 Transition metal oxides are the other commonly used electrode materials for SCs, at first the noble metal oxides such as RuO2 [22] and RhOx [23], etc. are extensively studied because of their high faradic capacitance and good conductivity.…”