High inorganic content with percolated structure in pore-filling membrane: Platform for functional membranes based on zirconium phosphate

Abstract

Organic-inorganic composite membranes are used in various applications, such as proton-conducting electrolyte membranes for PEMFCs. In this study, we filled a polyethylene porous substrate with only but plenty of inorganics (around 48 wt.%), zirconium acetylacetonate, the precursor of zirconium phosphate (ZrP)-based inorganics (AcAc-Zr). It was confirmed that the AcAc-Zr in the substrate was converted into ZrP derivatives in situ, keeping the high contents. TEM-EDS analysis revealed that the pores were continuously filled with ZrP, indicating that ZrP was percolated due to the high contents and the original structure of the porous substrate. The conductivities of these ZrP, ZrHEDP, and ZrATMP films were sufficiently high: on the order of 1 mS cm–1 (80°C and 95% relative humidity condition).