Performance Recovery in Degraded Carbon-Based Electrodes for Capacitive Deionization

Bei Li, Tianye Zheng, Sijia Ran, Mingzhe Sun, Jin Shang, Haibo Hu, Po Heng Lee, Steven T. Boles

Research output: Journal article publicationJournal articleAcademic researchpeer-review

6 Citations (Scopus)

Abstract

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.

Original languageEnglish
Pages (from-to)1848-1856
Number of pages9
JournalEnvironmental Science and Technology
Volume54
Issue number3
DOIs
Publication statusPublished - 4 Feb 2020

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry

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