Three-electrode structure for capacitive deionization desalination

A three-electrode structure for desalination having a capacitive discharge ionization (CDI) cell, the capacitive discharge ionization cell, comprising:

• a watertight casing having a left side and a right side;
• a conductive first current collector disposed inside the casing along the casing's left side;
• a conductive second current collector disposed inside the casing along the casing's right side;
• a positive electrode and a negative electrode extending at right angles away from the left and right sides of the casing, respectively, the positive electrode being in electrical contact with the first current collector, the negative electrode being in electrical contact with the second current collector;
• a central electrode (CE) disposed inside the casing and extending from top to bottom of the casing, the central electrode being centrally located between and spaced apart from the first current collector and the second current collector, the central electrode defining a perforated plate, a non-conducting, ion permeable material encapsulates the central electrode and electrically isolating the positive and negative electrodes from the central electrode;
• a first water flow channel between the positive contacting current collector and the material encapsulating the central electrode and a second water flow channel between the negative contacting current collector and the material encapsulating the central electrode, the water flow channels extending from top to bottom of the casing and allowing influent and effluent water flow through the CDI cell, wherein the flow channels are defined by a nonconductive, first planar water flow channel spacer disposed between the first current collector and the material encapsulating the CE and a nonconductive, second planar water flow channel spacer disposed between the second current collector and the material encapsulating the CE;
• and
• a voltage source supplying a reference potential to the central electrode, a positive potential relative to the reference potential to the positive electrode, and a negative potential relative to the reference potential to the negative electrode, the positive and negative potentials being equal in magnitude but opposite in polarity, wherein the voltage source comprises a three-terminal DC power supply having neutral, positive and negative voltage outputs, the neutral voltage output being connected to the CE, the positive voltage output being connected to the positive electrode, and the negative voltage output being connected to the negative electrode.