Polymer Electrolytes with High Ionic Concentration for Fuel Cells and Electrolyzers

Abstract

As fuel cells and electrolyzers require higher performance and durability, the design aspects of polymer electrolytes continue to evolve. One distinctive trend in achieving a remarkably improved performance of electrochemical devices is to equip polymer electrolytes with high ionic concentration. This Review presents recent implementations of polymer electrolytes with a high ionic concentration in electrochemical devices. The synthetic approaches, benefits in device performance, challenges, and prospects of polymer electrolytes are summarized. The goal of this article is to explain the working principles of polymer electrolytes with a high acid concentration in high-performing fuel cells and electrolyzers, to survey recent achievements, and to address remaining technical issues. As well as informing polymer scientists, this Review may generate interest in the broader community of emerging fields to make use of these promising materials in tackling tough scientific challenges.

Hydrogen Separation and Purification from Various Gas Mixtures by Means of Electrochemical Membrane Technology in the Temperature Range 100–160 °C

“…Some other advantages include their fast electrode kinetics, enhanced mass transport, higher tolerance to impurities such as CO (up to 3 vol.%), and better sustain-ability [13,[36][37][38]. Recent advances in other HT membranes, specifically for fuel cells, have been made [39][40][41]. These include, for example, phosphonated poly(pentafluorostyrene) for fuel cells and fuel cells based on quaternary ammonium-biphosphate ion pairs.…”

Hydrocarbon-based Pemion™ proton exchange membrane fuel cells with state-of-the-art performance

“…33 The peak power density of the MEA was not reported. Also the excellent work of Kreuer and co-workers 28,70 with the 10 mm sulfonated polysulfone (S360) with PBIOO blend membrane (peak power density > 2.5 W cm À2 under H 2 /O 2 and 95% RH and 2b, the peak power density of the Pemion™ MEA is similar to that of PFSA reference ($1.1 W cm À2 ). However, at a potential relevant for automotive applications of 0.6 V, the power density of the Pemion™ MEA (0.83 W cm À2 ) is still $20% lower than that of the PFSA reference (1.0 W cm À2 ).…”

“…Thus, the volumetric density of protonic sites is lower for hydrocarbon ionomers at the same IEC. 28 Consequently, hydrocarbon-based PEMs typically require a signicantly higher amount of acid functional groups per repeat unit (>2Â), and hence a greater ion exchange capacity (IEC), approx. 2 mmol g À1 and above, to achieve similar protonic conductivity to PFSAs.…”

Essentials of High Performance Water Electrolyzers – From Catalyst Layer Materials to Electrode Engineering

“…Therefore, for more information concerning polymer membrane materials, the readers are referred to a recent review. [153]…”