High performance aqueous symmetric supercapacitors based on advanced carbon electrodes and hydrophilic poly(vinylidene fluoride) porous separator

The main components of a supercapacitor include two electrodes, electrolyte, and a separator, which are all essential to specify the energy storage capability of the device. In this work, two kinds of porous carbon materials have been fabricated via different routes using pomelo peel as raw material. The specific surface area are 1187 m(2) g(-1) for the nanosized worm-like carbon, and 1744 m(2) g(-1) for the nitrogen-enriched microsized carbon. Both carbon materials demonstrate excellent energy storage capability as electrodes for aqueous supercapacitors. According to the three-electrode measurements, the worm-like carbon exhibits a high specific capacitance of 316 F g(-1) at 0.2 A g(-1) in 6 M KOH, while the other exhibits 471 F g(-1) due to the highly enriched nitrogen atoms in structure. In addition, two-electrode coin-type cells have been assembled with the carbon materials as electrodes and hydrophilic poly(vinylidene fluoride) porous membrane as the separator. The assembled cells exhibit high specific capacitances, excellent rate performance and superior cycling durability because of a synergistic effect of the high performance carbon electrodes and hydrophilic porous separator. (C) 2018 Elsevier B.V. All rights reserved.