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Title: On the hydrophilicity of electrodes for capacitive energy extraction

Abstract

The so-called Capmix technique for energy extraction is based on the cyclic expansion of electrical double layers to harvest dissipative energy arising from the salinity difference between freshwater and seawater. Its optimal performance requires a careful selection of the electrical potentials for the charging and discharging processes, which must be matched with the pore characteristics of the electrode materials. While a number of recent studies have examined the effects of the electrode pore size and geometry on the capacitive energy extraction processes, there is little knowledge on how the surface properties of the electrodes affect the thermodynamic efficiency. In this paper, we investigate the Capmix processes using the classical density functional theory for a realistic model of electrolyte solutions. The theoretical predictions allow us to identify optimal operation parameters for capacitive energy extraction with porous electrodes of different surface hydrophobicity. Finally, in agreement with recent experiments, we find that the thermodynamic efficiency can be much improved by using most hydrophilic electrodes.

Authors:
 [1];  [2];  [1];  [3];  [4];  [1]
  1. Univ. of California, Riverside, CA (United States). Dept. of Chemical and Environmental Engineering. Dept. of Mathematics
  2. (China). State Key Lab. of Chemical Engineering
  3. (China). Dept. of Chemical Engineering
  4. East China Univ. of Science and Technology, Shanghai (China). State Key Lab. of Chemical Engineering
Publication Date:
Research Org.:
Univ. of California, Riverside, CA (United States); East China Univ. of Science and Technology, Shanghai (China)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); Chinese Scholarship Council
Contributing Org.:
Tsinghua Univ., Beijing (China)
OSTI Identifier:
1340470
Alternate Identifier(s):
OSTI ID: 1324475
Grant/Contract Number:  
AC05-00OR22725
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Physics. Condensed Matter
Additional Journal Information:
Journal Volume: 28; Journal Issue: 46; Journal ID: ISSN 0953-8984
Publisher:
IOP Publishing
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; energy extraction; salinity exchange; electric double layer; classical density functional theory

Citation Formats

Lian, Cheng, East China Univ. of Science and Technology, Shanghai, Kong, Xian, Tsinghua Univ., Beijing, Liu, Honglai, and Wu, Jianzhong. On the hydrophilicity of electrodes for capacitive energy extraction. United States: N. p., 2016. Web. doi:10.1088/0953-8984/28/46/464008.
Lian, Cheng, East China Univ. of Science and Technology, Shanghai, Kong, Xian, Tsinghua Univ., Beijing, Liu, Honglai, & Wu, Jianzhong. On the hydrophilicity of electrodes for capacitive energy extraction. United States. doi:10.1088/0953-8984/28/46/464008.
Lian, Cheng, East China Univ. of Science and Technology, Shanghai, Kong, Xian, Tsinghua Univ., Beijing, Liu, Honglai, and Wu, Jianzhong. Wed . "On the hydrophilicity of electrodes for capacitive energy extraction". United States. doi:10.1088/0953-8984/28/46/464008. https://www.osti.gov/servlets/purl/1340470.
@article{osti_1340470,
title = {On the hydrophilicity of electrodes for capacitive energy extraction},
author = {Lian, Cheng and East China Univ. of Science and Technology, Shanghai and Kong, Xian and Tsinghua Univ., Beijing and Liu, Honglai and Wu, Jianzhong},
abstractNote = {The so-called Capmix technique for energy extraction is based on the cyclic expansion of electrical double layers to harvest dissipative energy arising from the salinity difference between freshwater and seawater. Its optimal performance requires a careful selection of the electrical potentials for the charging and discharging processes, which must be matched with the pore characteristics of the electrode materials. While a number of recent studies have examined the effects of the electrode pore size and geometry on the capacitive energy extraction processes, there is little knowledge on how the surface properties of the electrodes affect the thermodynamic efficiency. In this paper, we investigate the Capmix processes using the classical density functional theory for a realistic model of electrolyte solutions. The theoretical predictions allow us to identify optimal operation parameters for capacitive energy extraction with porous electrodes of different surface hydrophobicity. Finally, in agreement with recent experiments, we find that the thermodynamic efficiency can be much improved by using most hydrophilic electrodes.},
doi = {10.1088/0953-8984/28/46/464008},
journal = {Journal of Physics. Condensed Matter},
number = 46,
volume = 28,
place = {United States},
year = {Wed Sep 14 00:00:00 EDT 2016},
month = {Wed Sep 14 00:00:00 EDT 2016}
}

Journal Article:
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