Further Thermal Reduction of Reduced Graphene Oxide Aerogel with Excellent Rate Performance for Supercapacitors

Featured Application The prepared three-dimensional graphene with porous structure and high electrical conductivity is an ideal electrode material for electrochemical energy storage devices, including supercapacitors and lithium ion batteries, etc. Abstract Preparation of pure three-dimensional graphene (3DG) with high rate performance for supercapacitors is critical for fast rate charge/discharge. Here, 3DG was prepared via thermal annealing of freeze-dried reduced graphene oxide (RGO) hydrogel under inert gas protection. The formed 3DG as an electrode material for supercapacitors revealed a specific capacitance of 115 Fg(-1) at a current density of 1 Ag-1, and a high capacitance retention of 70% as current density increased to 40 Ag-1. The excellent rate capability was mainly attributed to the reserved porous structure and higher electrical conductivity for 3DG after thermal reduction than its RGO hydrogel precursor.