TY - JOUR
T1 - Performance Recovery in Degraded Carbon-Based Electrodes for Capacitive Deionization
AU - Li, Bei
AU - Zheng, Tianye
AU - Ran, Sijia
AU - Sun, Mingzhe
AU - Shang, Jin
AU - Hu, Haibo
AU - Lee, Po Heng
AU - Boles, Steven T.
N1 - Funding Information:
The authors would like to acknowledge the financial support from the “Electrochemical Energy Storage Systems” (1-ZVD2) project at Hong Kong Polytechnic University.
Publisher Copyright:
Copyright © 2019 American Chemical Society.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/2/4
Y1 - 2020/2/4
N2 - Limitations of capacitive deionization (CDI) and future commercialization efforts are intrinsically bound to electrode stability. In this work, thermal treatments are explored to understand their ability to regenerate aged CDI electrodes. We demonstrate that a relatively low thermal treatment temperature of ∼500 °C can sufficiently recover the lost salt adsorption capacity of degraded electrodes. Furthermore, a systematic study of electrode replacement clarifies that the desalination ability loss and regeneration for a CDI cell are isolated to the aged anode, as expected. Characterizations of surface functionalities support that the acidic oxygen-containing functional groups formed in situ during cycling undergo thermal decomposition during treatment. The modified Donnan model quantitatively confirms that the surface charges originate from the formation/decomposition of functional groups. Accordingly, the lost pore volume and the increased resistance are recovered during thermal treatments, while the surface morphologies and pore structure of the electrodes are well-preserved. Therefore, thermal treatment can be applied practically to extend the lifetime of aged electrodes. This study also offers insights into strategies for minimizing electrode degradation or in situ regeneration such that the technology gains momentum for future commercialization.
AB - Limitations of capacitive deionization (CDI) and future commercialization efforts are intrinsically bound to electrode stability. In this work, thermal treatments are explored to understand their ability to regenerate aged CDI electrodes. We demonstrate that a relatively low thermal treatment temperature of ∼500 °C can sufficiently recover the lost salt adsorption capacity of degraded electrodes. Furthermore, a systematic study of electrode replacement clarifies that the desalination ability loss and regeneration for a CDI cell are isolated to the aged anode, as expected. Characterizations of surface functionalities support that the acidic oxygen-containing functional groups formed in situ during cycling undergo thermal decomposition during treatment. The modified Donnan model quantitatively confirms that the surface charges originate from the formation/decomposition of functional groups. Accordingly, the lost pore volume and the increased resistance are recovered during thermal treatments, while the surface morphologies and pore structure of the electrodes are well-preserved. Therefore, thermal treatment can be applied practically to extend the lifetime of aged electrodes. This study also offers insights into strategies for minimizing electrode degradation or in situ regeneration such that the technology gains momentum for future commercialization.
UR - http://www.scopus.com/inward/record.url?scp=85079020656&partnerID=8YFLogxK
U2 - 10.1021/acs.est.9b04749
DO - 10.1021/acs.est.9b04749
M3 - Journal article
C2 - 31886659
AN - SCOPUS:85079020656
SN - 0013-936X
VL - 54
SP - 1848
EP - 1856
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 3
ER -