title: Characterization of Resistances of a Capacitive Deionization System.
abstract: Capacitive deionization (CDI) is a promising desalination technology, which operates at low pressure, low temperature, requires little infrastructure, and has the potential to consume less energy for brackish water desalination. However, CDI devices consume significantly more energy than the theoretical thermodynamic minimum, and this is at least partly due to resistive power dissipation. We here report our efforts to characterize electric resistances in a CDI system, with a focus on the resistance associated with the contact between current collectors and porous electrodes. We present an equivalent circuit model to describe resistive components in a CDI cell. We propose measurable figures of merit to characterize cell resistance. We also show that contact pressure between porous electrodes and current collectors can significantly reduce contact resistance. Lastly, we propose and test an alternative electrical contact configuration which uses a pore-filling conductive adhesive (silver epoxy) and achieves significant reductions in contact resistance.
authors.affiliation: †Department of Mechanical Engineering, Stanford University Stanford, 440 Escondido Mall, Stanford, California 94305, United States.|‡Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States.
authors.forename: Yatian
authors.initials: Y
authors.lastname: Qu
authors.affiliation: ‡Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States.
authors.forename: Theodore F
authors.initials: TF
authors.lastname: Baumann
authors.affiliation: †Department of Mechanical Engineering, Stanford University Stanford, 440 Escondido Mall, Stanford, California 94305, United States.
authors.forename: Juan G
authors.initials: JG
authors.lastname: Santiago
authors.affiliation: ‡Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Stadermann
mesh_terms: D004560:Electricity; D004566:Electrodes; D004867:Equipment Design; D016062:Porosity; D012834:Silver / Q000737:chemistry; D012965:Sodium Chloride; D013816:Thermodynamics; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods*
chemical_list: D012834:Silver; D012965:Sodium Chloride