Resorcinol-formaldehyde resin based porous carbon materials with yolk-shell structure for high-performance supercapacitors

Novel yolk-shell structure of resorcinol-formaldehyde resin (YRF) is formed via the condensation polymerization of resorcinol and formaldehyde at 0 degrees C without any template. After carbonized and activated with KOH at 700 degrees C, the YRF based porous carbon materials are obtained and the unique yolk shell structure is remained. The specific surface area of the porous carbon materials is up to 1218 m(2) g(-1) through the N-2 adsorption-desorption method and many micropores and mesopores are formed in the carbonized materials which are beneficial for electrolyte transport. The specific capacitance of porous carbon material YRFC700-1:3 reaches 397.4 F g(-1) at the current density of 0.5 A g(-1) and the capacitance retention is 91.2% after 10,000 charge-discharge processes at large current density of 20 A g(-1). The strategy developed in this work provides a good example for making full use of polymer-based carbon materials. The good electrochemical performance demonstrates that the polymer-based carbon materials may have promising applications in high-performance of energy-storage devices. (C) 2016 Elsevier B.V. All rights reserved.