Abstract
The development of novel electrolytes and electrodes for supercapacitors is hindered by a gap of several orders of magnitude between experimentally measured and theoretically predicted charging time scales. Here, we propose an electrode model, containing many parallel stacked electrodes, that explains the slow charging dynamics of supercapacitors. At low applied potentials, the charging behavior of this model is described well by an equivalent circuit model. Conversely, at high potentials, charging dynamics slow down and evolve on two relaxation time scales: a generalized time and a diffusion time, which, interestingly, become similar for porous electrodes. The charging behavior of the stack-electrode model presented here helps to understand the charging dynamics of porous electrodes and qualitatively agrees with experimental time scales measured with porous electrodes.
- Received 21 November 2019
- Accepted 15 January 2020
DOI:https://doi.org/10.1103/PhysRevLett.124.076001
© 2020 American Physical Society
Physics Subject Headings (PhySH)
Synopsis
Improving Models of How Supercapacitors Charge
Published 20 February 2020
A new model more accurately predicts the charging time of real supercapacitors by better accounting for the structure of the device’s porous electrodes.
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