A review of recent advances in electrode materials and applications for flow-electrode desalination systems

Flow-electrode capacitive deionization (FCDI) is an emerging desalination technology that overcomes the drawbacks of traditional capacitive deionization (CDI) by providing larger salt removal capacity and continuous desalination operation. Various approaches to the choice of cell configurations and electrode materials allow FCDI to increase the salt removal performance and extend its potential applications. In particular, Faradaic electrode materials for FCDI have recently emerged due to their various advantages over capacitive material, which include higher salt removal rate, lower energy consumption, and the ability to selectively remove specific ions. In this review, we summarize the background technology and mechanism of the FCDI system with an emphasis on the development of electrode materials, including capacitive and redox active electrodes, as well as their role in the various applications for FCDI and its future direction.