Holey Layered Oxygen‐Rich Graphene Xerogels for High‐Performance Supercapacitors

Abstract

Holey layered oxygen‐rich graphene (HLGH) xerogel material is prepared with a green pore‐making agent (potassium ferrate, K2FeO4), whose morphology and pore structure are completely different from traditional 3D graphene xerogels. The extra oxygen‐containing functional groups existing around the in‐plane pores in HLGH xerogels can contribute more pseudocapacitance to the total capacitance. The optimal HLGH xerogels electrode material obtained a high specific capacitance of 329.5 F g−1 at 1 A g−1, which is much larger than that of traditional graphene xerogel (GH, 169.0 F g−1). Finally, the symmetric supercapacitor is assembled by using the HLGH xerogels, which achieves the high energy (25.3 Wh kg−1) and power densities (0.9 kW kg−1). The specific capacitance is only reduced by 10% after 5000 cycles, showing the excellent stability. Herein, an insight for designing a high‐performance graphene carbon‐based supercapacitor is provided.

In Situ S‐Doped Graphene Film using NaHSO3 as Sulfur Source for High‐Performance Flexible Supercapacitors

“…[1,2] Supercapacitors (SCs) are considered as ideal flexible electronics device candidates owing to high power density, long-term life, and fast charge/discharge rates. [3][4][5] As for electrode material, plentiful research efforts have been mainly devoted to the exploration of various carbonaceous materials including carbon black, carbon nanotubes, carbon nanofibers, and graphene. [6][7][8][9][10][11] Among them, graphene is regarded as one of the most desirable electrode materials applied in electrochemical energy storage devices, owing to its inherent physicochemical properties, such as excellent flexibility, electrical conductivity, stable chemical performance, and outstanding cycle stability.…”