Heating-Rate-Induced Porous α-Fe₂O₃ with Controllable Pore Size and Crystallinity Grown on Graphene for Supercapacitors

Abstract

Porous α-Fe2O3/graphene composites (S-PIGCs) have been synthesized by a simple hydrothermal method combined with a slow annealing route. The S-PIGCs as a supercapacitors electrode material exhibit an ultrahigh specific capacitance of 343.7 F g(-1) at a current density of 3 A g(-1), good rate capability, and excellent cycling stability. The enhanced electrochemical performances are attributed to the combined contribution from the optimally architecture of the porous α-Fe2O3, as a result of a slow annealing, and the extraordinary electrical conductivity of the graphene sheets.

Rapid microwave-assisted synthesis of mesoporous NiMoO4 nanorod/reduced graphene oxide composites for high-performance supercapacitors

“…The surface area of NiMoO4-rGO was calculated to be 50.8 m 2 g −1 , which was higher than that of NiMoO4 (30.9 m 2 g −1 ). This mesoporous structure with high surface area of composites can play an important role in providing rapid electrolyte transport, shorter diffusion paths, and more active sites for electrochemical reactions on the electrode surface [42].…”

Microwave assisted fabrication of a nanostructured reduced graphene oxide (rGO)/Fe2O3 composite as a promising next generation energy storage material

“…higher theoretical specic capacitance (1005 mA h g À1 ), facile synthetic approach, high corrosion resistance, earth-abundance, environmental friendliness and low processing cost. [18][19][20][21][22] However, Fe 2 O 3 alone as nanoparticles suffer from severe issues like low conductivity, high agglomeration and structural degradation during the charge and discharge cycling process which causes rapid loss of capacity caused by volume changes. 21 In this respect, highly thermal and electrically conductive graphene or rGO has been considered as the suitable support matrix for metal oxides to absorb the volume changes and to enhance the structural stability of the electrodes.…”

A High‐Energy Density Asymmetric Supercapacitor Based on Fe2O3 Nanoneedle Arrays and NiCo2O4/Ni(OH)2 Hybrid Nanosheet Arrays Grown on SiC Nanowire Networks as Free‐Standing Advanced Electrodes

“…An emerging new way to circumvent this vexing issue is to directly graft the electroactive Fe 2 O 3 onto conductive and robust skeletons, for example, graphene, carbon nanotubes, ordered multimodal porous carbon, and metal sulfide nanosheets to construct integrated hybrid electrode materials, which indeed shows relatively superior electrochemical properties than individual components due to the smart hybridization of the active materials and framework in synergy. [32][33][34][35][36] Despite much progress has been achieved by exploring various supporters, the trouble of unsatisfied energy storage capacity still exist in implementing the aforementioned composite as SC electrodes, probably because of the addition of polymer binder and conductive additive which unavoidably enhances the "dead" weight and impedes electron transfer, or the employment of press machine which causes the damage of structures of the active materials. Hence, there is an urgent need for searching for alternative suitable scaffolds for homogeneous distribution of the electroactive Fe 2 O 3 toward free-standing hybrid electrodes for high-performance SCs.…”