Robust three-dimensional porous rGO aerogel anchored with ultra-fine α-Fe₂O₃ nanoparticles exhibit dominated pseudocapacitance behavior for superior lithium storage

Based on the ultra-fast faradaic surface induced reversible redox reactions, pseudocapacitance behavior with rapid electrochemical kinetics can boost the high power density of lithium ion battery. In this work, a three-dimensional (3D) interconnected porous reduced graphene oxide network incorporated with homogeneously dispersed ultra-fine α-Fe₂O₃ nanoparticles (denoted α-Fe₂O₃@3DrGO) is subtly synthesised through a facial hydrothermal self-assembly process. Such desirable hierarchical structure delivers an ever-increasing pseudocapacitance storage as anode, achieving an unprecedented rate capacity (921.6, and 812.4 mA h g⁻¹ at 1 and 5 A g⁻¹) and a superior cycle performance with ultra-high capacity (1198.6 mA h g⁻¹ at 1 A g⁻¹ over 200 cycles), which is almost the best result reported so far. Even at a high current density of 5 A g⁻¹, it still maintains the excellent cycle stability with a capacity of 396.6 mA h g⁻¹ after 2000 cycles. Such outstanding electrochemical performance may be ascribed to the synergy of the robust structure, porous surface morphology as well as accompanying dominated pseudocapacitance behavior. We hope this work can provide a novel strategy for realizing high rate and stable cycle performances in lithium storage.