Three-dimensional porous reduced graphene oxide/PEDOT:PSS aerogel: Facile preparation and high performance for supercapacitor electrodes

Graphene derivatives have great potential in the field of energy storage, because of their high specific surface area, great electrical conductivity, and stable electrochemical properties. For the graphenebased electrodes with a three-dimensional (3D) porous structure, the interlayer stacking of the graphene sheets largely limits their capacitive performance, and thus hinders their wide applications. In this work, we successfully developed a lightweight, freestanding and 3D porous reduced graphene oxide (rGO)/poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) composite aerogel by incorporating the conducting polymer PEDOT:PSS into interconnected rGO networks through a facile, low-cost and all-water-processable two-step synthesis route. PEDOT:PSS covering on the rGO sheets was found to not only prevent the stacking of rGO sheets, but also greatly improve the ion accessibility and mechanical stability of this highly porous spongy meshwork. Due to the synergistic effect of rGO and PEDOT:PSS, the aerogel electrodes delivered a high gravimetric specific capacitance (471 F g(-1) at 0.2 A g(-1)), an excellent rate capability, and a remarkable capacitance retention (98.71% over 20,000 cycles at 20 A g(-1)). Furthermore, the aerogel-based symmetric supercapacitor exhibited a wide potential window (0-1.4 V) and an excellent energy storage performance. A high energy density of 48.18 Wh kg(-1) with the power density of 1.4 kW kg(-1) at 0.5 A g(-1), or an energy density of 32.67 Wh kg(-1) corresponding to the great power density of 14,000 W kg(-1) at 5 A g(-1) was achieved. These results demonstrate the great potential of the rGO/PEDOT:PSS aerogel as an excellent electrode material for energy storage applications. (C) 2020 Elsevier Ltd. All rights reserved.