AUTHOR=East Allan L. L. , Nguyen Cuong M. , Hempelmann Rolf 

TITLE=A 2023 update on the performance of ionic-liquid proton-exchange-membrane fuel cells

JOURNAL=Frontiers in Energy Research

VOLUME=Volume 11 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2023.1031458

DOI=10.3389/fenrg.2023.1031458

ISSN=2296-598X

ABSTRACT=A mini-review is provided of the literature concerning the performance of proton-exchange-membrane fuel cells (PEMFCs) containing (immobilized) ionic liquids (ILs) as possible electrolytes, focusing on papers reporting performance metrics (power and current densities).  For over a decade, and especially for Combined Heat and Power Applications, there has been a drive to design an ionic-liquid-holding membrane that could operate well in non-humidifying (water-free) conditions above 100°C. Such a goal has not yet been achieved: reported power densities are still below those of traditional low-temperature fuel cells.  Progress has been slow.  Other recent reviews have already pointed to three main issues: poor conductivity, poor cathode (oxygen-reduction) kinetics, and seepage of the liquid from the membrane.  Here, we use performance metric data to highlight the lack of improvement in the past 5 years, summarize which IL-PEMFC systems have performed the best so far, and attempt to improve the understanding of their conductivity mechanisms.  It is hoped that the improved description of the Grotthuss H+ relays will aid in the design of IL-PEMs with improved conductivity.