Recent advances in NASICON-type materials for high-performance capacitive deionization: design strategies and mechanistic insights

Capacitive deionization (CDI) is a sustainable water treatment technology known for its energy efficiency. Notably, electrode materials are key factors influencing ion adsorption efficiency. Conventional carbon-based materials often exhibit limited adsorption capacity and poor cycling stability, which significantly hinder their effectiveness, especially under complex water conditions. In contrast, NASICON-type (sodium super ionic conductor) materials, characterized by their three-dimensional open framework and superior electrochemical activity, offer higher adsorption capacity and enhanced stability, making them promising candidates for CDI applications. However, comprehensive reviews focusing on their design principles, adsorption behavior, and associated challenges in the context of CDI remain scarce. This review systematically explores the design strategies and adsorption performance of NASICON-type materials, emphasizing approaches such as optimizing charge and electron dynamics, inhibiting structural agglomeration, and incorporating buffer architecture to enhance CDI performance. Furthermore, advanced solutions to key challenges are discussed, including the use of machine learning for designing high-entropy materials, integrating NASICON electrodes into various CDI architectures, and coupling CDI with complementary technologies like photocatalysis and electrocatalysis. By providing these perspectives, this review contributes to the design of high-performance NASICON materials and the continued evolution of efficient, long-lasting, and application-ready CDI technologies.