Targeted filling of silica in Nafion by a modified in situ sol-gel method for enhanced fuel cell performance at elevated temperatures and low humidity.

Herein, a modified in situ sol-gel method was applied to prepare the Nafion/silica composite membrane with targeted filling of silica into ionic clusters. The low humidity (20-60% RH) proton conductivity of Nafion was therefore doubled at elevated temperatures (110-120 °C), and the high-temperature fuel cell performance was significantly improved by 45%.