Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8071113 | Energy | 2018 | 34 Pages |
Abstract
Supercapacitors can provide a high specific power and long cycle life but suffer a significant self-discharge limiting their application as a stand-alone energy storage device. A new hybrid supercapacitor with incorporated galvanic cell components was proposed to mitigate the self-discharge problem. The hybrid supercapacitor was similar to a conventional supercapacitor with two active carbon electrodes separated by a polymer electrolyte membrane containing 1.5â¯M zinc sulfate. However, a zinc foil and a copper foil were used as the current collectors for the negative and the positive electrodes respectively, which can provide a micro-current to compensate the self-discharge current. The hybrid supercapacitor exhibited a maximum specific capacitance of 55â¯F gâ 1 and specific energy of 4.51â¯Wh kgâ1 with a charge efficiency of 90%. The capacitance retention of the hybrid supercapacitor was 80% after 2000 cycles. The open circuit voltage of the charged hybrid supercapacitor was stable and declined slightly from initial 0.90â¯V-0.85â¯V in a month. The results demonstrate that via replacement of a pair of conventional metal current collectors with a galvanic couple the ubiquitous self-discharge problem can be significantly mitigated and the storage time can be prolonged to meet the requirement for stand-alone applications.
Related Topics
Physical Sciences and Engineering
Energy
Energy (General)
Authors
Y. Wang, X. Qiao, C. Zhang, Xiangyang Zhou,