Yoo, Dong-Yeop Jung, Jiyoon Park, Young Sang Choi, Gwan Hyun Yoon, Ho Gyu Hwang, Seung Sang Lee, Albert S. S. 2024-01-19T09:00:09Z 2024-01-19T09:00:09Z 2023-08-31 2023-09 2050-7488 https://pubs.kist.re.kr/handle/201004/113333 Cross-linkable organosilsesquioxanes were synthesized for application as catalyst binders in high temperature polymer electrolyte membrane fuel cells (HT-PEMFCs). Four different organic functional groups were examined including methyl, phenyl, fluoroalkyl, and fluorophenyl and their chemical, physical, surface, and electrochemical properties were characterized. The effect of surface hydrophobicity on a HT-PEMFC membrane electrode assembly was elucidated, showing that organosilsesquioxanes with lower surface tension or higher hydrophobicity towards water and phosphoric acid could be considered as a key parameter for HT-PEMFC performance. Fuel cell tests showed that the pentafluorophenyl-functionalized organosilsesquioxane showed improved H-2/air performance (a peak power density of 527 mW cm(-2) at 0.4 V) compared to the MEA with PTFE (a peak power density of 425 mW cm(-2) at 0.4 V). Short term durability tests for 500 h showed that membrane electrode assemblies with alternative binders were stable and the developed organosilsesquioxane binders are a viable alternative to PTFE-based binders, all the while having additional advantages in vastly simplified ink slurry preparation through increased dispersibility in alcohol-water mixtures. English Royal Society of Chemistry Mitigating phosphoric acid migration in high temperature polymer electrolyte membrane fuel cells with hydrophobic polysilsesquioxane-based binders Article 10.1039/d3ta03592a 1 Journal of Materials Chemistry A, v.11, no.34, pp.18426 - 18433 Journal of Materials Chemistry A 11 34 18426 18433 N scie scopus 001050065200001 Chemistry, Physical Energy & Fuels Materials Science, Multidisciplinary Chemistry Energy & Fuels Materials Science Article HYBRID DURABILITY