Carbon polyaniline capacitive deionization electrodes with stable cycle life

Journal Article · Wed Apr 24 00:00:00 EDT 2019 · Desalination

DOI:https://doi.org/10.1016/j.desal.2019.04.002· OSTI ID:1509578

Evans, Samuel F. ^[1]; Ivancevic, Marko R. ^[2]; Wilson, Devin J. ^[2]; Hood, Zachary D. ^[3]; Adhikari, Shiba P. ^[2]; Naskar, Amit K. ^[4]; Tsouris, Costas  ^[2]; Paranthaman, M. Parans  ^[1]

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1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); The Univ. of Tennessee, Knoxville, TN (United States)
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
4. The Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Electrode materials for capacitive deionization (CDI), an energy efficient method for desalination, were developed in this work. Waste-tire derived carbon (TC) coated with polyaniline was used to form a carbon polymer composite (CPC). CPC was used as an electrode in CDI configurations to determine the salt adsorption capability of the material. Chemical treatment of TC with KOH led to an enhancement in surface area to 952 m²/g and microporosity in the sub-2-nm range. This unique microstructure is considered to be beneficial for effective ion uptake in CDI applications. The capacitance of the electrodes was further enhanced through surface coating with polyaniline, resulting in a specific capacitance of 168.2 F/g. In batch cell testing with 1.2 V applied potential, the salt adsorption capacity (SAC), measured in mg of salt adsorbed per gram of active material, in a 1500–1700 ppm KCl solution was measured at 14.2 mg/g. Scale-up of the process with ionic-membrane-assisted CDI (MCDI) led to improvement in SAC at 18.9 mg/g. Further, cycling tests revealed that the electrodes had comparable or better longevity compared to other CDI materials, retaining >92.8% charging capacity after 300 cycles. In conclusion, high adsorption capacities for other salts such as LiCl, NaCl, MgCl₂ and CaCl₂ have been found.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1509578
• Alternate ID(s): OSTI ID: 1547472
• Journal Information: Desalination, Vol. 464, Issue C; ISSN 0011-9164
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY