Abstract
Recent years have witnessed the broad use of carbon electrodes for electric double layer capacitors (EDLCs) because of large surface area, high porosity and low cost. Whereas experimental investigations are mostly focused on the device performance, computational studies have been rarely concerned with electrochemical properties at conditions remote from equilibrium, limiting their direct applications to materials design. Through a comprehensive analysis of extensive experimental data with various machine-learning methods, we report herein quantitative correlations between the structural features of carbon electrodes and the in-operando behavior of EDLCs including energy and power density. Machine learning allows us to identify important characteristics of activated carbons useful to optimize their efficiency in energy storage.
| Original language | English |
|---|---|
| Pages (from-to) | 147-152 |
| Number of pages | 6 |
| Journal | Carbon |
| Volume | 157 |
| DOIs | |
| State | Published - Feb 2020 |
Funding
This research is sponsored by the Fluid Interface Reactions, Structures, and Transport (FIRST) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences . The computational work used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy , under Contract DE-AC02-05CH11231 . A.G. was supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1326120 . Appendix A The EDLC performance depends on, in addition to electrode materials, the properties of electrolytes and operational conditions such as the electrochemical potential window and charging discharging rates. In order to minimize the number of input variables affecting the performance of an EDLC device, our machine-leaning analysis is focused on experimental results for the specific capacitance and the power density of pristine activated carbon materials. Besides, we consider only the results measured with three-electrode cell in 6?M KOH aqueous solution with the voltage window of 1?V. In comparison to that in two-electrode measurements, a three-electrode cell provides a more precise control of both potential and current, and thus is able to better distinguish the electrochemical properties of different electrode materials [3]. Because experimental data are scarce for materials with low specific surface areas, we added three points to replenish the results at zero surface area. All data points are from the literature [27?33] and listed in Supporting Information (SI). Also presented in SI are equations to calculate the capacitance, energy density, and power density of EDLCs.This research is sponsored by the Fluid Interface Reactions, Structures, and Transport (FIRST) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences. The computational work used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy, under Contract DE-AC02-05CH11231. A.G. was supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1326120.
| Funders | Funder number |
|---|---|
| DOE Office of Science | |
| EDLC | |
| Energy Frontier Research Center | |
| National Energy Research Scientific Computing Center | |
| Office of Basic Energy Sciences | |
| National Science Foundation | DGE-1326120 |
| U.S. Department of Energy | |
| Foundation for Ichthyosis and Related Skin Types | |
| Interface | |
| Office of Science | DE-AC02-05CH11231 |