A Mini-Review of Ion Exchange Membranes for Capacitive Deionization: Research Progress, Commercialization, and Patent Trends
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Abstract
With global water scarcity worsening, improving water treatment efficiency and sustainability has become a priority for governments worldwide. Ion exchange membranes (IEMs) in capacitive deionization (CDI) are regarded as a promising water treatment technology, capable of meeting the urgent demand for sustainable water resource utilization. In this mini-review, we have provided an overview of the research progress made in IEM-assisted CDI (MCDI), focusing on membrane materials, system configurations, patent analysis, and commercialization. Bibliometric and citation analyses reveal a surge in research and patent activity related to MCDI over the past five years, highlighting their growing global interest. The commercialization of MCDI is accelerating, driven by government funding in Europe, the U.S., Japan, and South Korea, alongside industry innovations improving efficiency and scalability. Patent analysis identifies dominant technical topics, patent strength, and the evolving patent numbers and expiration patterns of MCDI. Although challenges remain regarding cost, membrane durability, and scalability, MCDI is set to be a transformative technology in next-generation water purification and electrochemical separation systems. This review examines the current state of MCDI across various countries, offering insights into its role in advancing sustainable water resource management and enhancing water treatment technologies.
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