New insight into the performance analysis of flow-electrode capacitive deionization by varying the operation voltage

Document Type : Article


1 Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, Iran

2 Separation and Conversion Materials Laboratory, Korea Institute of Energy Research, Daejeon, Republic of Korea



In the flow-electrode capacitive deionization (FCDI), the highly activated porous carbon electrodes of slurry phase flows through the channels of current collectors and adsorbs the salt ions when a voltage is applied. In this study, the effect of voltage on the performance of a FCDI cell is experimentally investigated. The voltage is applied on the top corner of a FCDI cell (Vapply) and simultaneously the voltage of central cell (Vcell) is measured. The experiments were conducted by applying voltages from 0.6 to 3.9 V. The experimental results show that the difference between Vapply and Vcell is a function of salt concentrations of the feed water. The higher voltages (Vapply>1.2V) can be used for increasing the salt removal efficiency (E) for higher salt water concentrations without electrolysis. Also, the results show that E increases along with the applied voltage. A series of pH measurements were done in regard to investigation of electrolysis point of the setup.


References   1. Zhang, C., He, D., Ma, J., et al. Faradaic reactions   in capacitive deionization (CDI) - problems and possibilities:   A review", Water Research, 128, pp. 314{330   (2018).   2. Suss, M.E., Porada, S., Sun, X., et al. Water desalination   via capacitive deionization: what is it and what   can we expect from it?", Energy Environ. Sci., 8, p.   2296 (2015).   3. Porada, S., Zhao, R., van der Wal, A., et al. Review   on the science and technology of water desalination by   capacitive deionization", Prog. In Mater. Sci., 58, pp.   1388{1442 (2013).   4. Laxman Kunjali K. Water desalination by nanostructuring   enhanced control of capacitive deionization",   PhD Thesis, Department of Electrical and Computer   Engineering College of Engineering, Sultan Qaboos   University, Sultanate of Oman, (2015).   5. Laxman Kunjali, K., Al Gharibi, L., and Dutta, J.   Capacitive deionization with asymmetric electrodes",   Electrode capacitance vs electrode surface area, Electrochimica   Acta, 176, pp. 420{425 (2015).   6. Zou, L., Morris, G., and Qi, D. Using activated carbon   electrode in electrosorptive deionisation of brackish   water", Desalination, 225, pp. 329{340 (2008).   7. Xu, P., Drewes, J.E., Heil, D., et al. Treatment of   brackish produced water using carbon aerogel-based   capacitive deionization technology", Water Res., 42,   pp. 2605{2617 (2008).   8. Porada, S., Weinstein, L., Dash, R., et al. Water   desalination using capacitive deionization with   microporous carbon electrodes", ACS Appl. Mater.   Interfaces, 4, pp. 1194{1199 (2012).   9. Tsouris, C., Mayes, R., Kiggans, J., et al. Mesoporous   carbon for capacitive deionization of saline water",   Environ. Sci. Technol., 45, pp. 10243{10249 (2011).   10. Wang, L., Wang, M., Huang, Z.-H., et al. Capacitive   deionization of NaCl solutions using carbon nanotube   sponge electrodes", J. Mater. Chem., 21, pp. 18295{   18299 (2011).   11. Wang, H., Zhang, D., Yan, T., et al. Graphene   prepared via a novel pyridine-thermal strategy for   capacitive deionization", J. Mater. Chem., 22, pp.   23745{23748 (2012).   12. Kwak, N.-S., Koo, J.S., Hwang, T.S., et al. Synthesis   and electrical properties of NaSS-MAA-MMA   cation exchange membranes for membrane capacitive   deionization (MCDI)", Desalination, 285, pp. 138{146   (2012).   13. Choi, Y.W., Lee, M.S., Yang, T.H., et al. Ion exchange   membrane for ow- electrode capacitive deionization   device and ow-electrode capacitive deionization   device including the same", Patent, EP, 2857442   (2015).   14. Zhao, R., Biesheuvel, P.M., and van der Wal, A. Energy   consumption and constant current operation in   membrane capacitive deionization", Energy Environ.   Sci., 5, pp. 9520{9527 (2012).   1426 M. Nikfar et al./Scientia Iranica, Transactions C: Chemistry and ... 28 (2021) 1421{1427   15. Suss, M.E., Baumann, T.F., Bourcier, W.L., et   al. Capacitive desalination with ow-through electrodes",   Energy Environ. Sci., 5, pp. 9511{9519   (2012).   16. Porada, S., Sales, B.B., Hamelers H.V.M., et al.   Water desalination with wires", J. Phys. Chem. Lett.,   3, pp. 1613{1618 (2012).   17. Xu, X.T., Allah, A.E., Wang, C., et al. Capacitive   deionization using nitrogen-doped mesostructured   carbons for highly e_cient brackish water desalination",   Chemical Engineering Journal, 362, pp. 887{   896 (2019).   18. Liu, Y., Xu, X., Lu, T., et al. Nitrogen-doped   electrospun reduced graphene oxide-carbon nano_ber   composite for capacitive deionization", RSC Advances,   5(43), pp. 34117{34124 (2015).   19. Zhang, J., Yan, T., Fang, J., et al. Enhanced capacitive   deionization of saline water using N-doped rod-like   porous carbon derived from dual-ligand metal-organic   frameworks", Environmental Science: Nano, 7, pp.   926{937 (2020).   20. Xu, X., Tan, H., Wang, Z., et al. Extraordinary   capacitive deionization performance of highly-ordered   mesoporous carbon nano-polyhedra for brackish water   desalination", Environmental Science: Nano, 6(3), pp.   981{989 (2019).   21. Xu, X., Liu, Y., Wang, M., et al. Hierarchical   hybrids with microporous carbon spheres decorated   three-dimensional graphene frameworks for capacitive   applications in supercapacitor and deionization", Electrochimica   Acta, 193, pp. 88{95 (2016).   22. Xu, X., Wang, M., Liu, Y., et al. Metal-organic   framework-engaged formation of a hierarchical hybrid   with carbon nanotube inserted porous carbon   polyhedra for highly e_cient capacitive deionization",   Journal of Materials Chemistry A., 4(15), pp. 5467{   5473 (2016).   23. Wang, M., Xu, X., Liu, Y., et al. From metal-organic   frameworks to porous carbons: A promising strategy   to prepare high-performance electrode materials for   capacitive deionization", Carbon, 108, pp. 433{439   (2016).   24. Wang, M., Xu, X., Tang, J., et al. High performance   capacitive deionization electrodes based on ultrathin   nitrogen-doped carbon/graphene nano-sandwiches",   Chemical Communications, 53(78), pp. 10784{10787   (2017).   25. Wang, Z., Xu, X., Kim, J., et al. Nanoarchitectured   metal-organic framework/polypyrrole hybrids   for brackish water desalination using capacitive deionization",   Materials Horizons, 6, pp. 1433{1437 (2019).   26. Xu, X., Li, C., Wang, C., et al. Three-dimensional   nano architecture of carbon nanotube-interwoven   metal-organic frameworks for capacitive deionization   of saline water", ACS Sustainable Chemistry & Engineering,   7(16), pp. 13949{13954 (2019).   27. Jeon, S.I., Park, H.R., Yeo, J.G., et al. Desalination   via a new membrane capacitivedeionization process   utilizing ow-electrodes", Energy Environ. Sci., 6, pp.   1471{1475 (2013).   28. Yang, S.C., Jeon, S., Kim, H., et al. Stack design and   operation for scaling up the capacity of ow-electrode   capacitive deionization technology", ACS Sustainable   Chem. Eng., 4, pp. 4174{4180 (2016).   29. Cho, Y., Lee, K.S., Yang, S.C., et al. A novel threedimension   system utilizing honeycomb-shaped lattice   structures for ow-electrode capacitive deionization",   Energy Environ Sci., 10, pp. 1746{1750 (2017).   30. Xu, X., Wang, M., Liu, Y., et al. Ultrahigh desalinization   performance of asymmetric ow-electrode   capacitive deionization device with an improved operation   voltage of 1.8 V", ACS Sustainable Chemistry &   Engineering, 5(1), pp. 189{195 (2016).   31. Wang, M., Hou, S., Liu, Y., et al. Capacitive neutralization   deionization with ow electrodes", Electrochimica   Acta, 216, pp. 211{218 (2016).   32. Hatzell, K.B., Iwama, E., Ferris, A., et al. Capacitive   deionization concept based on suspension electrodes   without ion exchange membranes", Electrochem Commun,   43, pp. 18{21 (2014).   33. Porada, S., Weingarth, D., Hamelers, H.V.M., et al.   Carbon ow electrodes for continuous operation of   capacitive deionization and capacitive mixing energy   generation", J. Mater. Chem. A., 2, pp. 9313{9321   (2014).   34. Rommerskirchen, A., Gendel, Y., and Wessling, M.   Single module ow-electrode capacitive deionization   for continuous water desalination", Electrochem. Commun.,   60, pp. 34{37 (2015).   35. Liang, P., Sun, X., Bian, Y., et al. Optimized   desalination performance of high voltage ow-electrode   capacitive deionization by adding carbon black in owelectrode",   Desalination, 420, pp. 63{69 (2017).   36. Nikfar, M., Alemrajabi, A., Choo, K.Y., et al. Experimental   study on the structure of spacer in a owelectrode   capacitive deionization", Desalination and   Water Treatment, 184, pp. 86{93 (2020).   37. Nikfar, M., Alemrajabi, A., and Kim, D.K. A review   study on the capacitive desalination set, and   experimental feasibility study on coupling of FCDI   and solar energy", Journal of Energy Engineering &   Management, In Persian, In press (2020).   38. Jeon, S., Yeo, J.G., Yang, S.C., et al. Ion storage   and energy recovery of a ow electrode capacitive   deionization process", Journal of Materials Chemistry   A., 2, pp. 6378{6383 (2014).   39. Yang, S.C., Choi, J., Yeo, J.G., et al. Flow-electrode   capacitive deionization using an aqueous electrolyte   with a high salt concentration", Environ. Sci. Technol,   50, pp. 5892{5899 (2016).   40. Park, H.R., Choi, J., Yang, S.C., et al. Surfacemodi   _ed spherical activated carbon for high carbon   M. Nikfar et al./Scientia Iranica, Transactions C: Chemistry and ... 28 (2021) 1421{1427 1427   loading and its desalting performance in ow-electrode   capacitive deionization", The Royal Society of Chemistry,   6, p. 69720 (2016).