Abstract
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. High adsorption capacities for other salts such as LiCl, NaCl, MgCl2 and CaCl2 have been found.
| Original language | English |
|---|---|
| Pages (from-to) | 25-32 |
| Number of pages | 8 |
| Journal | Desalination |
| Volume | 464 |
| DOIs | |
| State | Published - Aug 15 2019 |
Funding
The carbon synthesis research (MPP) was supported by the U.S. Department of Energy (DOE), Office of Science , Office of Basic Energy Sciences , Materials Sciences and Engineering Division . SFE is grateful for a fellowship from the Bredesen Center for Interdisciplinary Graduate Education. Part of this research (ZDH) was completed at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. ZDH was also supported by a Graduate Research Fellowship award from the National Science Foundation ( DGE-1650044 ). CT was supported by the Laboratory Directed Research and Development (LDRD) program of the Oak Ridge National Laboratory . The carbon synthesis research (MPP) was supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division. SFE is grateful for a fellowship from the Bredesen Center for Interdisciplinary Graduate Education. Part of this research (ZDH) was completed at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. ZDH was also supported by a Graduate Research Fellowship award from the National Science Foundation (DGE-1650044). CT was supported by the Laboratory Directed Research and Development (LDRD) program of the Oak Ridge National Laboratory. This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the US DOE. The U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript or allow others to do so, for United States Government purposes. The US DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).