Editors' Choice-Review-Activated Carbon Electrode Design: Engineering Tradeoff with Respect to Capacitive Deionization Performance

Design and optimization of electrode materials plays the pivotal role on the performance of capacitive deionization (CDI). Activated carbon (AC) has been a workhorse material for electrode fabrication in capacitive technologies. Several modification methods have been reported with enhanced activity and versatility attributes. Undeniably, tuning and tailoring AC properties have opened avenues for broadening the scope of applications, by meeting necessary features of electrodes for a given CDI cell configuration. This review traces the beneficial and also detrimental effects from various modifiers on AC electrodes with respect to CDI performance. Furthermore, a comprehensive classification of CDI cells based on different architectural aspects with a comparative performance is presented. On this basis, the tradeoff between physical, chemical, electrochemical properties in the course of electrode modification and the interdependence between electrode design and CDI cell configuration are discussed with disclosing some prospective guidelines on AC electrode design. It is important to evaluate the electrode materials and modifications in the way of practical including not only the electrode design, but also the cell architecture and operational parameters. This review aims to raise the attention on the rational electrode design by taking into account all necessary features of electrode in a given cell configuration.