Poly(4-vinylpyridine) Based Semi-Interpenetrating Cross-Linked High Temperature Proton Exchange Membranes for Fuel Cells

A series of high temperature polymer electrolyte membranes are fabricated using a commercially low-cost poly(4-vinylpyridine). Because of the existence of the amount of pyridine groups, poly(4-vinylpyridine) possesses a strong interaction with phosphoric acid molecules. In order to improve the dimensional and mechanical stability, the semi-interpenetrating network is constructed by employing poly(vinyl chloride) as the supporting material because of its good compatibility with poly(4-vinylpyridine) and poly(vinyl benzyl chloride) as the cross-linker due to the high nucleophilicity. The macromolecular cross-linked semi-interpenetrating membranes exhibit high conductivity and good mechanical properties simultaneously. Consequently, the optimized membrane (i.e., 10% CL-PP) with an acid doping content of 176% displays a good conductivity of 45.8 mS cm–1 at 160 °C and a high mechanical strength of 10.3 MPa at room temperature. The H2–O2 high temperature proton exchange membrane fuel cell based on the above-mentioned membrane achieves a peak power density of 478 mW cm–2 at 160 °C without any backpressure. This work provides a facile method on the preparation of high-performance semi-interpenetrating membranes for fuel cell applications.