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Capacitive Porous Electrodes. P.M. (Maarten) Biesheuvel Wageningen, the Netherlands Wetsus, Leeuwarden, the Netherlands. Capacitive Deionization. A close relative …. Supercapacitors. Capacitive Deionization (CDI). Flow-through. Static. 3. “Capacitive Deionization” – Web of Science.
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Capacitive Porous Electrodes • P.M. (Maarten) Biesheuvel • Wageningen, the Netherlands • Wetsus, Leeuwarden, the Netherlands
A close relative … Supercapacitors Capacitive Deionization (CDI) Flow-through Static 3
(Membrane) Capacitive Deionization without ion-exchange membranes with ion-exchange membranes
Capacitive Deionization Adsorption Porous electrode Vcell Porous electrode 6
Capacitive Deionization Release Porous electrode short-circuit Porous electrode 7
Salt adsorption and Charge in Microporous Carbons Equilibrium, @ Vcell=1.2 V
Desalination with Wires Results published in: Porada, S., B.B. Sales, H.V.M. Hamelers, and P.M. Biesheuvel (2012) The Journal of Physical Chemistry Letters 3: 1613-1618
Ion transport phenomena in realistic systems:Instead of “Na+ Cl-” also H+ OH- HCO3- etc.
Three examples for amphoteric ionic systemse.g., CO32-HCO3-H2CO3 Capacitive Deionization Current-induced membrane discharge CO2 energy
Example 2. Overlimiting current in Ion-exchange membranes membrane discharge water in membrane pores
Example 2. Overlimiting current in Ion-exchange membranes Current Induced Membrane Discharge
Modeling of ion transport in amphoteric systems e.g., CO32- + H+ HCO3-
Advantages of fast ion equilibration • By addition of balances, for each “group” such as for CO2/HCO3-/CO32-, only one balance per group remains • and, all dummy parameters R disappear ! • very elegant to include now reactions at solid surfaces, or evaporation liquid gas JNH3(aq) JNH3(g) JNH4+(aq) JOH-(aq) JH+(aq)