Hydrodynamic regulation of flow‐electrode capacitive deionization by Tesla‐type flow channels for lithium extraction

Flow‐electrode capacitive deionization (FCDI) for lithium extraction is often limited by coupled slurry hydrodynamics, particle redistribution, and electrochemical transport, especially at high solid loading. Here, Tesla‐type asymmetric flow channels were introduced to regulate slurry transport and intensify charge/ion transfer in FCDI. Computational fluid dynamics simulations showed improved flow uniformity, suppressed particle accumulation, and reduced flow resistance relative to a serpentine channel. Electrochemical impedance spectroscopy and distribution of relaxation times analyses further indicated lower transport resistance and enhanced coupled charge‐transfer/ion‐migration processes. Consequently, the Tesla‐type system achieved an average salt removal rate of 0.327 μmol cm −2 min −1 , and a charge efficiency of 81.2% at 1.2 V. After optimization, the system reached 0.868 μmol cm −2 min −1 and 93.9% charge efficiency at 1.6 V. These results demonstrate a device‐level transport intensification strategy for slurry‐electrode electrochemical separations.