Jinhui Li, Guoping Zhang, C. Fu
Mar 31, 2017
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Influential Citations
96
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Quality indicators
Journal
Journal of Power Sources
Abstract
Abstract Nitrogen/sulfur co-doped and hierarchical porous graphene hydrogels (DHGHs) are prepared by facile self-assembly process. The results show that the pH values of preparation process significantly affect the microstructures and electrochemical properties of DHGHs and the mechanism has been discussed. The as-prepared DHGHs can be directly used as binder-free electrodes to assemble full-cell supercapacitor devices. It is surprising that the DHGHs prepared at basic condition (DHGH-12) delivers a specific capacitance of 251 F g −1 (0.5 A g −1 ). Moreover, the DHGH-12 shows rectangular cyclic voltammetry shape at a high scan rate of 3000 mV s −1 and symmetrical galvanostatic charge/discharge curves at 100 A g −1 which exhibits a specific capacitance of 136.5 F g −1 , a high energy density of 4.74 Wh kg −1 and high power density of 25.47 kW kg −1 . Additionally, DHGH-12 presents superior cycling stability (96.8% retention after 2000 cycles at 20 A g −1 ) in 6 M KOH solution. Therefore, the novel DHGHs can be considered as promising candidate for high energy density supercapacitors at high rates.