Electrode materials for capacitive deionization: A review

Capacitive deionization (CDI) is an emerging technology for energy-efficient water desalination, and attracts more and more attention in recent years. It has been concluded that CDI technology shows competitiveness and perspectives on seawater desalination and wastewater treatment. The ionic adsorption mechanism can be clarified by electric double-layer capacitive adsorption and pseudocapacitive adsorption. The performance of CDI depends on both device and materials. The adsorption capacity and energy efficiency was improved significantly with fast growth of researches on material and novel energy storage techniques. This review summarizes researches on CDI technologies with an emphasis on electrode material design and improved adsorption performance.