Fabrication of PBI/SPOSS hybrid high-temperature proton exchange membranes using SPAEK as compatibilizer

Because of the harsh operating circumstances of high temperature over 100 degrees C and strong acidity, it is of great significance to explore some new methods on the developments of high-performance membrane materials using in high-temperature proton exchange membrane fuel cells (HT-PEMFCs). In current work, with the assistance of newly designed sulfonated poly (aryl ether ketone) (SPAEK) compatibilizer, some hydrophilic and acidophilic polyhedral-oligosilsesquioxane nanoparticles bearing sulfuric acid groups (SPOSS) were successfully incorporated into a soluble arylether-type polybenzimidazole (Ph-PBI) matrix via an in situ sol-gel process to obtain a new family of hybrid membranes with an improved overall performance. As a result, these hybrid membranes exhibited enhanced acid absorption ability and doping levels at 120 degrees C, improved acid retention ability and attractive mechanical-dimensional stability. More importantly, the proton conductivity of a phosphoric acid doped hybrid membrane reached 126 mS cm(-1) at 200 degrees C. This membrane was also suitable for membrane electrode assemblies (MEAs), and a maximum power density of 300 mW cm(-2) could be achieved at 160 degrees C without humidity.

Automated summary

Exploring new methods for developing high-performance membrane materials for use in high-temperature proton exchange membrane fuel cells is important due to the harsh operating conditions. In this study, a new family of hybrid membranes was successfully obtained through the incorporation of sulfonated poly (aryl ether ketone) (SPAEK) compatibilizer and polyhedral-oligosilsesquioxane nanoparticles bearing sulfuric acid groups (SPOSS) into a soluble arylether-type polybenzimidazole (Ph-PBI) matrix. These hybrid membranes exhibited enhanced acid absorption, doping levels, acid retention, and mechanical-dimensional stability, with a high proton conductivity of 126 mS cm(-1) at 200 degrees C. They were also suitable for membrane electrode assemblies (MEAs) and achieved a maximum power density of 300 mW cm(-2) at 160 degrees C without humidity.