Organic-inorganic composite membranes as addition of SiO{sub}2 for high temperature-operation in polymer electrolyte membrane fuel cells (PEMFCs)

摘要

Organic-inorganic composite membranes for operation above 100 ℃ in polymer electrolyte membrane fuel cells (PEMFCs) were prepared, characterized and cell-tested. Composite membranes were obtained by mixing organic polymers, which have a SO{sub}3H group as a proton conductor with inorganic material, SiO{sub}2, using the sol-gel process. Electron probe micro analyser (EPMA) was used to show the homogeneous and uniform distribution of SiO{sub}2. The physico-chemical properties of all membranes were investigated regarding their tensile strength, water uptake and thermogravimetric analyzer (TGA). Due to a higher water uptake and thermal stability of composite membranes, the cell performances at high temperatures above 100 ℃, were improved. In addition, the SiOH group in the composite membrane was shown to play a major role in capturing water strongly and maintaining proton conductivity even at high temperature. Furthermore, the fuel cell performance of organic-inorganic composite membranes was superior to that of the Nafion membrane at high current density over all ranges of temperature.