Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7726170 | Journal of Power Sources | 2018 | 7 Pages |
Abstract
A novel asymmetrical-bipolar electrochemical capacitor system leveraging the contributions of a Zn-CNT asymmetrical electrode and a KOH-H2SO4 dual-pH electrolyte was developed. The positive and negative electrodes operated in electrolytes with different pH, exploiting the maximum potential of both electrodes, which led to a cell voltage of 2.4Â V. The potential tracking of both electrodes revealed that the Zn negative electrode could maintain a potential at â1.2Â V, while the CNT positive electrode can be charged to +1.2Â V without significant irreversible reactions. A bipolar ion exchange membrane has effectively separated the acid and alkaline from neutralization, which resulted in stable performance of the device with capacitance retention of 94% and coulombic efficiency of 99% over 10,000 cycles. This asymmetrical-bipolar design overcomes the thermodynamic limit of water decomposition, opening a new avenue towards high energy and high power density aqueous-based ECs.
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Haoran Wu, Keryn Lian,