Review on the polymer materials for capacitive deionization

Capacitive deionization (CDI) emerges as an attractive alternative to conventional desalination approaches, offering a harmonious blend of low energy consumption, architecture simplicity, and environmental consideration. The evolution of CDI technology, tracing the trajectory from advancements in electrode materials to the introduction of innovative operational modes, all gracefully interwoven with the essential role of polymers in augmenting CDI's efficiency and stability. The synergistic effect of polymers/functional nanomaterial composites across diverse CDI systems has heralded noteworthy strides in enhancing desalination performance in terms of salt removal and sustained cyclic stability. This review comprehensively examines and categorizes polymer-based composites in CDI technology, delving into their multifaceted roles as electrode materials, additive binders, and membranes. It also evaluates a spectrum of design and fabrication techniques for polymer-based composites of CDI systems. In light of these insights, the review provides suggestions for future research directions to unlock latent potential in this critical field.