Anion effects on thermopower of electrochemical systems for low-grade heat harvesting

Improvement of the thermopower (α) is essential for enhancing the energy conversion efficiency of a thermally regenerative electrochemical cycle (TREC). Here, we utilize the coordinating nature of anions to modulate the desolvation and reorganization entropy changes during the redox reaction in the...

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Main Authors: Li, Xiaoya, Wu, Angyin, Li, Jia, Li, Zongkang, Lee, Donghoon, Lee, Seok Woo
Other Authors: School of Electrical and Electronic Engineering
Format: Article
Language:English
Published: 2023
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Online Access:https://hdl.handle.net/10356/172127
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1721272024-01-12T15:41:24Z Anion effects on thermopower of electrochemical systems for low-grade heat harvesting Li, Xiaoya Wu, Angyin Li, Jia Li, Zongkang Lee, Donghoon Lee, Seok Woo School of Electrical and Electronic Engineering Rolls-Royce@NTU Corporate Lab Engineering::Materials::Energy materials Electrodes Energy Conversion Efficiency Improvement of the thermopower (α) is essential for enhancing the energy conversion efficiency of a thermally regenerative electrochemical cycle (TREC). Here, we utilize the coordinating nature of anions to modulate the desolvation and reorganization entropy changes during the redox reaction in the aqueous electrochemical system. We show that the preference of anions for an increased α roughly follows the reverse order of the Hofmeister series, with noncoordinating chaotropic anion ClO4- enabling the highest α among the tested anions under the same conditions. Leveraging this finding, we demonstrate a TREC system with a CuHCFe cathode, Fe2+/Fe3+ anode, and ClO4- ion electrolytes and achieve a full-cell α of −3.040 mV K-1. The energy efficiency is 4.1% (27% of the Carnot efficiency) when the cell operates between 10 and 60 °C without heat recuperation. This study provides valuable insights into enhancing α through tailored counterions, highlighting the promising potential of TREC for low-grade energy harvesting. National Research Foundation (NRF) Submitted/Accepted version This work was supported by the National Research Foundation, Prime Minister’s Office, Singapore under its NRF-ANR Joint Programme (NRF2019-NRF-ANR052 KineHarvest). 2023-11-27T01:35:04Z 2023-11-27T01:35:04Z 2023 Journal Article Li, X., Wu, A., Li, J., Li, Z., Lee, D. & Lee, S. W. (2023). Anion effects on thermopower of electrochemical systems for low-grade heat harvesting. ACS Energy Letters, 8(10), 4061-4068. https://dx.doi.org/10.1021/acsenergylett.3c01406 2380-8195 https://hdl.handle.net/10356/172127 10.1021/acsenergylett.3c01406 2-s2.0-85173151680 10 8 4061 4068 en NRF2019-NRF-ANR052 KineHarvest ACS Energy Letters © 2023 American Chemical Society. All rights reserved. This article may be downloaded for personal use only. Any other use requires prior permission of the copyright holder. The Version of Record is available online at http://doi.org/10.1021/acsenergylett.3c01406. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Engineering::Materials::Energy materials
Electrodes
Energy Conversion Efficiency
spellingShingle Engineering::Materials::Energy materials
Electrodes
Energy Conversion Efficiency
Li, Xiaoya
Wu, Angyin
Li, Jia
Li, Zongkang
Lee, Donghoon
Lee, Seok Woo
Anion effects on thermopower of electrochemical systems for low-grade heat harvesting
description Improvement of the thermopower (α) is essential for enhancing the energy conversion efficiency of a thermally regenerative electrochemical cycle (TREC). Here, we utilize the coordinating nature of anions to modulate the desolvation and reorganization entropy changes during the redox reaction in the aqueous electrochemical system. We show that the preference of anions for an increased α roughly follows the reverse order of the Hofmeister series, with noncoordinating chaotropic anion ClO4- enabling the highest α among the tested anions under the same conditions. Leveraging this finding, we demonstrate a TREC system with a CuHCFe cathode, Fe2+/Fe3+ anode, and ClO4- ion electrolytes and achieve a full-cell α of −3.040 mV K-1. The energy efficiency is 4.1% (27% of the Carnot efficiency) when the cell operates between 10 and 60 °C without heat recuperation. This study provides valuable insights into enhancing α through tailored counterions, highlighting the promising potential of TREC for low-grade energy harvesting.
author2 School of Electrical and Electronic Engineering
author_facet School of Electrical and Electronic Engineering
Li, Xiaoya
Wu, Angyin
Li, Jia
Li, Zongkang
Lee, Donghoon
Lee, Seok Woo
format Article
author Li, Xiaoya
Wu, Angyin
Li, Jia
Li, Zongkang
Lee, Donghoon
Lee, Seok Woo
author_sort Li, Xiaoya
title Anion effects on thermopower of electrochemical systems for low-grade heat harvesting
title_short Anion effects on thermopower of electrochemical systems for low-grade heat harvesting
title_full Anion effects on thermopower of electrochemical systems for low-grade heat harvesting
title_fullStr Anion effects on thermopower of electrochemical systems for low-grade heat harvesting
title_full_unstemmed Anion effects on thermopower of electrochemical systems for low-grade heat harvesting
title_sort anion effects on thermopower of electrochemical systems for low-grade heat harvesting
publishDate 2023
url https://hdl.handle.net/10356/172127
_version_ 1789482995080495104