Further thermal reduction of reduced graphene oxide aerogel with excellent rate performance for supercapacitors

Abstract

Preparation of pure three-dimensional graphene (3DG) with high rate performance for supercapacitors is critical for fast rate charge/discharge. Here, 3DGwas 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 F·g-1 at a current density of 1 A·g-1, and a high capacitance retention of 70% as current density increased to 40 A·g-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.