Electrodeposited Na-Birnessite on Carbon Cloth as Positive Electrode for Capacitive Deionization

Capacitive Deionization (CDI) based on traditional activated carbon (AC) electrodes faces some important intrinsic hurdles, such as the co-ion expulsion phenomenon and unwanted faradaic reactions, harming efficiency, operational stability, and electrode lifetime. The incorporation of ion-exchange membranes (IEM) in CDI, as free-standing films applied onto the electrodes, was shown to be an effective solution to improve charge efficiency and has led in fact to the commercialization of MCDI (membrane-CDI). An alternative way to improve CDI performance is the use of ion insertion materials, such as metal oxides and layered double hydroxides. In this work, we examine the performance of sodium-birnessite electrodeposited on commercial carbon cloth (CC) as the positive electrode of a flowby CDI cell, coupled to an ordinary AC / AEM stack as the negative electrode.