Ultrahigh Desalinization Performance of Asymmetric Flow-Electrode Capacitive Deionization Device with an Improved Operation Voltage of 1.8 V

Flow-electrode capacitive deionization (FCDI) is an emerging desalinization technology for high-concentration saline water treatment. However, in practical cases the operation voltage of FCDI is usually limited by the decomposition potential of water (1.23 V), which does harm the desalinization performance of FCDI. To address this issue, here for the first time we propose a novel asymmetric FCDI (AFCDI) device by using an activated carbon (AC)/MnO2 suspension as the positive electrode and AC suspension as the negative electrode. In AFCDI, the operation voltage can be improved to be 1.8 V, and a high salt removal efficiency of 78% is achieved in 0.1 M NaCl solution within 2 h, much higher than that for conventional FCDI (59%). To the best of knowledge, this value is also much higher than those for other FCDI devices reported previously. The present work may provide a promising high-performance desalinization device for high-concentration saline water treatment.