Fabrication and characterization of a porous carbon electrode for desalination of brackish water

Capacitive Performance and Tortuosity of Activated Carbon Electrodes with Macroscopic Pores

“…The intent of this experiment was to find what, if any, effect a change in concentration would have on the tortuosity of the electrodes for molarities similar to brackish water. 20,26 Modeling details.-The simulation model was based on the equations developed by Newman and co-workers for modeling porous electrodes, which have been used in many previous studies of such materials in applications such as supercapacitors, batteries, and capacitive deionization. 2,27,28 This model takes into account current and salt conservation in the electrolyte, current conservation in the solid matrix, and capacitive electrosorption within capacitive particles.…”

“…The solid electrode material was dissolved using 3 mL of N-methyl-2-pyrrolidone (NMP) solvent (MTI, USA) for every 1 gram of the powder mixture. 20 The carbon black was added in place of more active material to increase the electronic conductivity of the electrode so that the effective ionic conductivity was controlled by solution concentration and electrode tortuosity would be the determining factor of the experiments. 21,22 Once all ingredients were combined, the slurry was homogenized in a Thinky Planetary AR-310 Mixer with 15 minutes for mixing and 5 minutes for deaeration to ensure that the resulting slurry was completely homogeneous and free of air bubbles.…”

“…The molarity of the electrolyte was chosen as it is in the range of brackish water found in areas such as estuaries and deltas, which have salinity in between fresh and seawater. 20,24 The separators used, like the electrodes, were all submerged in DI water, followed by electrolyte, before assembly to ensure no air bubbles were trapped in the cell. The electrodes were then compressed between two solid graphite current collectors.…”

“…Solvent was removed from the sample through wetphase inversion, keeping the cast electrodes immersed in deionized water for several hours as water replaced NMP. 20,23 After the solvent was replaced with deionized water, the electrodes were air-dried for two hours to remove any water and trace amounts of solvent, and to make them machinable. The total porosity of each dried electrode was calculated as ε = 1 − ρ total /ρ solid , where ρ solid is the mass density of electrode constituents per unit solid volume (calculated to be 2.01 g/cc for the present recipe) and ρ total is total density of the electrode determined by independent measurements of electrode mass, thickness, and area.…”

Developing Nano-Structured Carbon Electrodes for Capacitive Brackish Water Desalination

“…In recent years, most reports in terms of CDI typically utilized various carbons, such as carbon aerogels [14][15][16], carbon cloth [18][19][20], carbon sheets [21], carbon nanotubes [22][23][24][25][26][27][28][29][30]and mesoporous carbon [31][32][33][34] etc as electrode materials because these materials have the advantage of high specific surface area, easy large scale production and environmental-friendly. I n a d d i t i o n t o C D I , m e m b r a n e c a p a c i t i ve deionization technology (MCDI) as an modification of CDI has attracted great attentions.…”