Phosphoric acid doped polybenzimidazole based polymer electrolyte membrane and functionalized SBA-15 mesoporous for elevated temperature fuel cell

Polymer electrolyte membrane as heart of a Fuel Cell electrochemical system to improve the durability of Fuel Cell performance at elevated temperatures requires the highest stability of proton conductivity, and thermal and chemical stability in long-term operations. In this research, the effect of SBA-15 mesoporous on the properties of H3PO4 doped polybenzimidazole/ionic liquid membranes were investigated for Fuel Cell applications under elevated temperatures. The H3PO4 doped polybenzimidazole based membranes were successfully fabricated by using polybenzimidazole (PBI) polymer with the same molecular weight and different amounts of 1,6-di (3-methylimidazolium) hexane dibromide dicationic ionic liquid (Mim(2)(+), Br-2(-) DIL), pure SBA-15 mesoporous and functionalized SBA-15 mesoporous with polyamidoamine groups (PAMAM mesoporous).The H3PO4 doped composite membrane containing 7% w/w Mim(2)(+), Br-2(-) DIL and 2% w/w PAMAM mesoporous with a superior mechanical strength and high thermal and chemical stability indicate a best electrochemical performance at 180 degrees C and 0.50 V under anhydrous conditions. The high proton conductivity stability of the composite membranes under elevated temperature and high humidity indicates that the introduction of PAMAM mesoporous with the NH2, NH and C=O groups on the inner wall of its pores significantly improves the ability retain of Mim(2)(+ )Br(2)(-) DIL and H3PO4. The results imply that use of PAMAM mesoporous as Mim(2)(+), Br-2(-) DIL and H3PO4 protectors against their leaching from the composite membrane is a new strategy to improve the stability of elevated temperature Fuel Cells performance in long-term operation. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This research successfully fabricated H3PO4 doped polybenzimidazole/ionic liquid composite membranes for high-temperature fuel cell applications by introducing SBA-15 mesoporous. The addition of PAMAM mesoporous as protectors significantly improved the stability of the composite membranes under elevated temperature conditions.