TY - JOUR
T1 - Driving Electrochemical Membrane Processes with Coupled Ionic Diodes
AU - Li, Victor
AU - Mathwig, Klaus
AU - Arotiba, O.A.
AU - Tshwenya, Luthando
AU - Batista Carneiro Neto, Evaldo
AU - Chaves Pereira, Ernesto
AU - Marken, Frank
N1 - F.M. thanks for the initial financial support by the EPSRC (EP/K004956/1). K.M. acknowledges financial support by Provincie Gelderland. E.B.C.N. and E.C.P. acknowledge 13 support from FAPESP (São Paulo Research Foundation, Grant Numbers 2013/07296-2, 2021/03592-2, 2022/06229-9), Shell, and the strategic importance of the support given by ANP (Brazil’s National Oil, Natural Gas and Biofuels Agency) through the R\&D levy regulation, CNPq (Grant Number 407878/2022), and CAPES (Code 001).
PY - 2023/3/24
Y1 - 2023/3/24
N2 - Ionic diodes have emerged repeatedly in the literature for gel interfaces, for nanopores and channels, for nano-/micro-fluidic systems, and for asymmetrically ionomer-covered microholes. Concentration polarisation is likely to be the key to understanding the diode function and the diode time constant diode, i.e. the time for approaching steady state following a potential/polarity switch. For frequencies higher than diode = 2f = (diode)-1, the polarization mechanism is too slow for ion current rectification. Below the frequency associated with the diode time constant, irreversibility in ion flow is induced and the diode switches between two resistive states at opposite potentials (“open” and “closed”). The irreversible flow of ions allows energy conversion from electrical to electrochemical. For energy conversion, two coupled ionic diodes are necessary driven by alternating current (AC) electricity to minimise driver electrode electrolysis and energy losses. Opportunities for AC-desalination and for electroosmotic water harvesting with coupled ionic diodes are discussed.
AB - Ionic diodes have emerged repeatedly in the literature for gel interfaces, for nanopores and channels, for nano-/micro-fluidic systems, and for asymmetrically ionomer-covered microholes. Concentration polarisation is likely to be the key to understanding the diode function and the diode time constant diode, i.e. the time for approaching steady state following a potential/polarity switch. For frequencies higher than diode = 2f = (diode)-1, the polarization mechanism is too slow for ion current rectification. Below the frequency associated with the diode time constant, irreversibility in ion flow is induced and the diode switches between two resistive states at opposite potentials (“open” and “closed”). The irreversible flow of ions allows energy conversion from electrical to electrochemical. For energy conversion, two coupled ionic diodes are necessary driven by alternating current (AC) electricity to minimise driver electrode electrolysis and energy losses. Opportunities for AC-desalination and for electroosmotic water harvesting with coupled ionic diodes are discussed.
U2 - 10.1016/j.coelec.2023.101280
DO - 10.1016/j.coelec.2023.101280
M3 - Review article
SN - 2451-9103
VL - 39
JO - Current Opinion in Electrochemistry
JF - Current Opinion in Electrochemistry
M1 - 101280
ER -