Electrochemical Strategies for CO 2 Capture: Synergistic Integration of Bipolar Membrane Electrodialysis and Capacitive Deionization Across Diverse Carbon Sources

ABSTRACT Electrochemical CO 2 capture offers a tunable, low‐temperature alternative to thermal methods. Among available strategies, bipolar membrane electrodialysis (BPMED) and capacitive deionization (CDI) are notable for their distinct mechanisms. BPMED induces pH swings via water dissociation, while CDI concentrates CO 2 ‐related ions through electric double‐layer adsorption. This review provides a comparative evaluation of BPMED and CDI in terms of working principles, energy performance, system integration, and application scenarios, including direct air capture (DAC), carbon capture from industrial flue gas, and direct ocean capture (DOC). BPMED demonstrates high‐capture rates and compatibility with in situ mineralization, whereas CDI offers lower energy demand and modular flexibility. Their respective strengths suggest potential complementarity—CDI may be better suited to treat liquid phase systems derived from point‐source emissions, in which dissolved inorganic carbon species dominate the ionic composition and the background of competing ions is relatively controllable; BPMED may be better suited for treating environmental carbon sources with large volumes, low concentrations or high ionic strength. This framework offers potential insights for developing scalable electrochemical CO 2 capture systems.