The advances development of proton exchange membrane with high proton conductivity and balanced stability in fuel cells.

In the proton exchange membrane fuel cell, proton exchange membrane (PEM) serves as both the main conductor of protons and the fuel‐blocking membrane. Thus, high proton conductivity and excellent stability are expected for PEMs at the same time. According to chemical structure, this review divides PEM into three groups. Recently, high‐performance PEM has been made possible by controlling chemical structure, organic–inorganic hybrid composite membranes, and nanofiber composite membranes. One of them, nanofiber composite membranes, is distinguished by long‐range order and is capable of achieving both strong proton conductivity with exceptional stability. The high‐performance PEM has been accomplished by the presence of an acid‐rich layer, acid–base interaction, and proton transport channel in PEMs are also summarized in this paper. We believe that our discussion will help the researcher create high‐performance PEM and pave the way for further developments in the field of energy materials as a whole. [ABSTRACT FROM AUTHOR]