Proton conductor, method for producing proton conductor, and fuel cell

Abstract

A proton conductor includes a coordination polymer having stoichiometrically metal ions, oxoanions, and proton coordinating molecules capable of undergoing protonation or deprotonation. The coordination polymer including coordination entities that are repeatedly coordinated to bond the coordination entities with one another. Each coordination entity is either a first coordination entity or a second coordination entity. The first coordination entity is one metal ion of the metal ions coordinated with either at least one oxoanion of the oxoanions or at least one proton coordinating molecule of the proton coordinating molecules. The second coordination entity is the metal ion coordinated with each of at least one oxoanion of the oxoanions and at least one proton coordinating molecule of the proton coordinating molecules. At least a part of the proton conductor is non-crystalline. The proton conductor has high ion conductivity at high temperature.