The effects of electrolyte on the supercapacitive performance of activated calcium carbide-derived carbon

• Published in: Journal of power sources 2013-03, Vol.226, p.202-209
• Main Authors: Wu, Hao, Wang, Xianyou, Jiang, Lanlan, Wu, Chun, Zhao, Qinglan, Liu, Xue, Hu, Ben'an, Yi, Lanhua
• Format: Article
• Language: English
• Subjects: Activation; Applied sciences; Calcium carbide-derived carbon; Capacitors. Resistors. Filters; Electrical engineering. Electrical power engineering; Electrolyte; Exact sciences and technology; Materials; Supercapacitors; Various equipment and components
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2012.11.014

Porous calcium carbide-derived carbon (CCDC) has been prepared by one-step route from CaC2 in a freshly prepared chlorine environment at lower temperature, and following activated by ZnCl2 to get activated CCDC. The performances of the supercapacitors based on activated CCDC as electrode active material in aqueous KOH, K2SO4, KCl and KNO3 electrolytes are studied by cyclic voltammetry, constant current charged/discharged, cyclic life and electrochemical impedance spectroscopy. It has been found that the supercapacitor using 6 M KOH as electrolyte shows an energy density of 8.3 Wh kg−1 and a power density of 1992 W kg−1 based on the total weight of the electrode active materials with a voltage range 0 V–1 V. Meanwhile, the specific capacitance of the supercapacitor in 6 M KOH electrolyte is 68 F g−1 at the scan rate of 1 mV s−1 in the voltage range of 0 V–1 V, the charge-transfer resistance is extremely low and the relaxation time is the least of all. The supercapacitor also exhibits a good cycling performance and keeps 95% of initial capacity over 5000 cycles. ► Comparable electrochemical behaviors of samples in various aqueous electrolytes. ► Comparisons of ions in various aqueous electrolytes are carried out. ► Sample in 6 M KOH has better capacitive behaviors and higher capacitance.