Nafion-sulfonated silica composite membrane for proton exchange membrane fuel cells under operating low humidity condition

Abstract

Sulfonated silica, synthesized by using tetraethyl orthosilicate and chlorosulfuric acid through calcination, was used as a filler to create Nafion-SSA composite membranes for applying proton exchange membrane fuel cells under low relative humidity (RH)condition. High water uptake and ion exchange capacity values were observed, and the Nafion-SSA composite membrane showed improved proton conductivity than that of the recast Nafion. The fuel cell operating at 80 °C under 20% RH with Nafion-SSA composite membrane showed 2.8 times higher maximum power density (454 mW cm −2 )and current density (2062 mA cm −2 )in comparison with the recast Nafion (159 mW cm −2 , 734 mA cm −2 ). The thermal stability and mechanical properties of recast Nafion and Nafion-SSA composite membranes were evaluated by TGA and Tensile test. © 2019