A polysesquioxane composition, comprising (i) a polysesquioxane matrix comprising sesquioxane moieties comprising a metallic element; (ii) a hydrophilic component; and (iii) a proton-conducting component, is provided. The metallic element can be silicon, a...

Provided are a proton-exchange membrane of which the ionic conductivity is high and the methanol crossover is low, and a fuel cell of high power that comprises the proton-exchange membrane. The proton-exchange membrane has a structure of mesogen-containing...