Magnetic-field-oriented mixed-valence-stabilized ferrocenium anion-exchange membranes for fuel cells

Water electrolysis: from textbook knowledge to the latest scientific strategies and industrial developments

“…7), most of which involve N-based groups 296,315–322 whereby piperidinium 323 and spirocyclic 280 are currently state-of-the-art. Besides non-N-based cationic groups like phosphonium, 269,324–327 phosphatranium, 328 S-based functional groups such as sulphonium 329–331 and metal-containing anion-conducting groups, such as complexes of ruthenium( ii ), 332,333 Cobaltocenium, 334–338 ferrocenium, 339 copper( ii ), 340 Nickel( ii ) 341,342 and gold( ii ) 343 have been described (Fig. 7).…”

“…Despite recent improvements in ex situ alkaline stability, 296,320,339,380–382 AEM in situ alkaline stability in operando AEMWE is still a major concern, suggesting that maybe more than one single factor should be taken into account.…”

Field Grand Challenge for Membrane Science and Technology

“…Characteristically, the membranes carry positive or negative fixed charges, which allow the passage of ions (Shin et al, 2017;Shehzad et al, 2021). Fuel cell membranes, such as proton exchange membranes (PEM) and anion exchange membranes (AEM) face substantial hurdles in cost and durability, quite apart from their task of maintaining high ion conductivity under various adverse environmental conditions such as elevated temperature and reduced humidity (Mustain et al, 2020;Jiao et al, 2021), but some approaches to achieving longer-term stability have been achieved (Liu et al, 2021b;Liu et al, 2022). Submissions on these membranes should include cell data and cell durability over a reasonable time.…”

Improving poly(arylene piperidinium) anion exchange membranes by monomer design

“…Both the polymer backbone and the tethered cations are prone to degrade via hydroxide attack, resulting in loss of mechanical integrity and ion conductivity, respectively. 14 To avoid backbone cleavage, polymers devoid of vulnerable ether bonds have been employed in AEMs, including polyethylenes, 15,16 polystyrenes, 17 polybenzimidazoles, 18 polyphenylenes 19 and poly(arylene alkylene)s. [20][21][22] In addition, the alkaline stability of various organic cations, including imidazolium, 23 quaternary ammonium (QA) [24][25][26][27] and organometallic cations, 28,29 have been studied as model compounds to identify suitable candidates. 30 In this context, different N-heterocyclic QA cations have emerged as synthetically accessible and generally highly alkali-stable ion-exchange groups.…”