Capacitive deionization for sustainable desalination: Advances in materials, design, operation, and stability
Journal
Desalination
Journal Volume
630
Start Page
120176
ISSN
00119164
Date Issued
2026-07-15
Author(s)
Abstract
Capacitive deionization (CDI) has emerged as a promising alternative desalination technology to address growing global water scarcity and security challenges. This review highlights current trends, critical challenges, and future opportunities in CDI, with a particular focus on the factors shaping its performance. Key aspects include electrode materials, morphological features, cell and system configurations, operational conditions, and fouling. Various electrode materials, such as carbons, nitrogen-doped carbons, metal-based materials, and polymer-based materials, are compared with respect to their advantages and limitations, including ion sorption capacity, conductivity, stability, and cost. The influence of surface area, pore structure, and morphology on ion transport and storage is systematically analyzed, with emphasis on their critical roles in enhancing desalination efficiency. CDI system designs, ranging from flow-by to flow-through cells to hybrid and stacked configurations, are evaluated for salt removal efficiency, energy consumption, scalability, and cost-effectiveness. Operational parameters, such as temperature, flow rate, and current density, are reviewed in conjunction with feedwater characteristics, including ion type and concentration, which significantly impact ion separation and selectivity. Particular attention is given to electrode fouling from organic deposition and inorganic scaling, which compromises ion transport and capacity. Strategies for mitigating fouling and ensuring long-term operational stability are also explored. Finally, the review emphasizes that advancing CDI requires integrated progress across material science and system engineering, including innovations in electrode design, intelligent operation, and sustainable brine management, to unlock its potential as an efficient, scalable, and environmentally viable desalination technology.
Subjects
Capacitive deionization
Desalination
Electrode fouling
Ion sorption
Porous electrode
Publisher
Elsevier B.V.
Type
journal article