Application of the macrohomogeneous line model for the characterization of carbon aerogel electrodes in capacitive deionization

Journal Article · Wed Jan 23 00:00:00 EST 2019 · Electrochimica Acta

DOI:https://doi.org/10.1016/j.electacta.2019.01.123· OSTI ID:1511934

Linneen, Nicholas ^[1]; Delnick, Frank ^[1]; Islam, Syed Z. ^[1]; Deshmane, Vishwanath G. ^[1]; Bhave, Ramesh ^[1]

---

1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division

Capacitive deionization (CDI) is a conceivable alternative desalination technology. Among the carbon materials studied as the deionizing electrode, carbon aerogels are a promising material due to their high surface area, structural designability and low resistivity. When evaluating carbons for CDI, their electrochemical properties are a crucial variable making the characterization of such properties vital. We apply a macrohomogenous model to evaluate carbon aerogels activated with CO₂ for various periods and varying Resorcinol/Catalyst, R/C, ratios during synthesis for estimation of their effective surface areas and pore sizes from an electrochemical standpoint. The porosities and structural properties of carbon aerogels were evaluated by nitrogen porosimetry, STEM, SEM and Electrochemical Impedance Spectroscopy (EIS). Results showed that the effective electrochemical surface areas calculated from the EIS were a small fraction of the areas estimated by nitrogen porosimetry, indicating that primarily the mesoporosity was utilized for deionization. Characteristic pore sizes calculated by the model were also close to the mesopore sizes estimated by the nitrogen adsorption isotherms, STEM and SEM measurements. Such results demonstrate the validity and value of the macrohomogenous model for evaluating effective electrochemical properties important for CDI applications.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE; ORNL Laboratory Directed Research and Development (LDRD) Program
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1511934
• Journal Information: Electrochimica Acta, Vol. 301; ISSN 0013-4686
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
macrohomogeneous line model
mesoporous carbon aerogel
capacitive deionization
desalination