Understanding and mitigating performance decline in electrochemical deionization

Capacitive deionization based on carbonaceous electrodes represents an energy-efficient technology suitable for low-salinity brackish water desalination where high recovery rates are critical to economic viability. Substituting insertion compounds for carbonaceous materials in electrochemical desalination electrodes enables higher ion adsorption capacities, excellent energy efficiency in higher salinity feedwaters, and selective removal of target ions. Despite the promise of electrochemical desalination processes, the durability of the electrode materials when treating complex waters is a documented issue that has not been systematically investigated. The present work reviews recent work on the impact of fouling on the performance of carbonaceous and insertion-based electrochemical desalination processes; discusses key factors controlling the corrosion/degradation of carbonaceous and insertion-based electrodes used in electrochemical desalination; and identifies potential strategies for improving the fouling tolerance and minimizing the corrosion or degradation of carbonaceous and insertion based electrodes.