Abstract: The present invention relates to a method for selective separation of positively charged monovalent ionic species from an ionic solution. The method comprises passing the ionic solution comprising a positively charged monovalent ion and a positively charged polyvalent ion through an electrode capacitor assembly comprising a first electrode and a second electrode, the electrodes comprising nanoporous carbon, wherein the first electrode is modified with sulfonate surface groups; and at least one flow channel for the passage of the solution. The method further comprises charging the electrode capacitor assembly (1) at a voltage of at least about 1.5 V; and/or (2) for scaled charging time of less than about 2.

Abstract: The present invention relates to a method for selective separation of positively charged monovalent ionic species from an ionic solution. The method comprises passing the ionic solution comprising a positively charged monovalent ion and a positively charged polyvalent ion through an electrode capacitor assembly comprising a first electrode and a second electrode, said electrodes comprising nanoporous carbon, wherein the first electrode is modified with sulfonate surface groups; and at least one flow channel for the passage of the solution. The method further comprises charging the electrode capacitor assembly (1) at a voltage of at least about 1.5 V; and/or (2) for scaled charging time of less than about 2.