Fabrication of a carbon electrode using activated carbon powder and application to the capacitive deionization process

A carbon electrode was fabricated in a simple and inexpensive manner through a drying process after casting an electrode slurry made of activated carbon powder (ACP) blended in a polymer solution on the current collector. The electrochemical characteristics of the fabricated electrode were analyzed, and the salt removal efficiency was studied by changing the electrode potential and flow rate after manufacturing a unit cell. An analysis of the characteristics of the fabricated electrode through cyclic voltammetry and impedance spectroscopy indicated a capacitance of 0.47 F/cm2. An electrochemical oxidation/reduction reaction occurred when the potential was applied under the influence of a functional group extant on the ACP surface. Salt removal tests using a 200-mg/L NaCl solution, conducted by preparing a CDI unit cell with the fabricated electrode, indicated a high average salt removal efficiency of 77.8% with an applied 1.5-V electrode potential and a 20-mL/min solution flow rate. The adsorbed ions were mostly desorbed within 1 min after applying a desorption potential, indicating that the desorption proceeded at a high speed.