A novel flow electrode capacitive deionization device with spindle-shaped desalting chamber

Flow-electrode capacitive deionization (FCDI) is an innovative technology in which an intermediate chamber plays an important role in the desalination process. However, relatively few studies have been conducted on the structures of these intermediate chambers. In this study, we propose a novel flow-electrode capacitive deionization device with a spindle-shaped inlet chamber (S-FCDI). The desalination rate of the S-FCDI under optimal operating conditions was 36% higher than that of the FCDI device with a conventional rectangular chamber (R-FCDI). The spindle-shaped chamber transferred 1.2 µmol more ions than the rectangular chamber, based on energy per joule. Additionally, we performed a detailed analysis of different inlet chamber shapes using computational fluid dynamics software. We concluded that S-FCDI has a relatively low flow resistance and almost no stagnation zone. This provides unique insights into the development of intermediate chambers. This study may contribute to the improvement of the desalination performance in industrial applications of FCDI.