Luis M. VARELA1, Hadrián MONTES-CAMPOS1, Jose M. OTERO-MATO1, Trinidad MÉNDEZ-MORALES1, Juan J. PARAJÓ1, Pablo VALLET1, Josefa SALGADO-CARBALLO1, Svyatoslav KONDRAT2, Esther RILO3, Oscar CABEZA3
1Universidade de Santiago de Compostela, Santiago de Compostela, Spain
2 Institute of Physical Chemistry, Warsaw, Warsaw, Poland
3Universidade de A Coruña, A Coruña, Spain
In this contribution we review the main results previously reported on charge transport in ionic fluids (ionic liquids (ILs) and electrolytes), and we focus our attention on the predictions of the ideal and random-alloy Bahe-Varela pseudolattice theories of transport , in which the IL mixture is modelled as a mixture of low and high mobility cells, and on its extension to nanoscopic media. Moreover, the mechanisms of charge transport under conditions of nanometric confinement (e.g., ionogels) result in an enhancement of diffusivities by more than two orders of magnitude, as well as in a change from a Vogel-Fulcher-Tamman into an Arrhenius-like thermal activation. We review some experimental evidence of enhanced charge transport in nanoconfined ionic fluids, and we report a generalized version of the theory that explicitly includes the presence of interfaces. Very specifically, we analyze recently reported measurements and molecular dynamics simulations  on ionogels that show increases of conductivity relative to the liquid samples, as well as an additional increase as some metal salt is added.
Acknowledgements: The financial support of the Spanish Ministry of Economy and Competitiveness (Projects MAT2017-89239-C2-1-P and MAT2017-89239- C2-2-P) is gratefully acknowledged. Moreover, this work was funded by the Xunta de Galicia (GRC ED431C 2020/10). All these research projects were partially supported by FEDER. The help of the technician M. C. V. from UDC for some of the measurements presented is also acknowledged. H. M.-C. and J. M. O.-M. thank the Spanish Ministry of Education for their FPU grants, and P. V. for his FPI grant. Facilities provided by the Galician Supercomputing Centre (CESGA) are also acknowledged.
 H Montes-Campos et al. J. Phys. Chem. C, 124, 11754-11759 (2020).
 P. Vallet et al. J. Mol. Liq. Submitted to publication (2022).