A high surface area N-doped holey graphene aerogel with low charge transfer resistance as high performance electrode of non-flammable thermostable supercapacitors

The high quality carbonaceous material with high surface area and low charge transfer resistance is vital for assembling the advanced supercapacitor. Herein, a novel kind of N-doped holey graphene aerogel (NHGA) is prepared. The NHGA has high specific BET surface area of 446m(2) g(-1) and low charge transfer resistance of 0.4 U. A large specific capacity of 318.3 F g(-1) is obtained at 0.5 A g(-1) in a three-electrode configuration in 6M KOH electrolyte, indicating the high capacity characteristic. As to the NHGA based symmetrical supercapacitor, the specific capacity of 96.0 F g(-1) can be achieved at 200 A g(-1), presenting its robust rate property. After 10,000 cycles at 2 A g(-1), the specific capacity is 262.5 F g(-1) with the capacity retention of 98.4%, showing its excellent cyclic stability. Notably, the energy density of 60.3Wh kg(-1) superior to that of the related typical reported supercapacitors, is obtained at the power density of 0.9 kW kg(-1) in a non-flammable ionic liquid EMIMTFSI-80 electrolyte, which is effective from 20 to 100 degrees C. Thus, the advanced electrochemical property of NHGA is distinctly valuable for the supercapacitor utilization especially in the extremely conditions such as fire safety and/ or high temperature. (C) 2019 Elsevier Ltd. All rights reserved.