A polybenzimidazole/graphite oxide based three layer membrane for intermediate temperature polymer electrolyte membrane fuel cells

A three layer membrane (TLM) of polybenzimidazole/graphiteoxide/polybenzimidazole (PBI/GO/PBI) has been fabricated as an electrolyte for intermediate temperature polymer exchange membrane fuel cells (IT-PEMFCs). The membrane is prepared by encapsulating a GO layer with two single PBI membranes via a layer-by-layer procedure and subsequently imbibed with phosphoric acid (PA). The TLM exhibits a lower swelling ratio than that of the pristine PBI membrane at the same PA loading time. The mechanical strength of the TLM could reach 28.6 MPa at 150 degrees C, significantly higher than that of a PBI membrane (12.2 MPa). The TLM is loaded with a PA amount of 2.23H(3)PO(4) molecules per repeat unit (PRU), which provides a proton conductivity of 0.0138 S cm (1) at 150 degrees C. The three layer structure promotes a membrane for PEMFCs with lower PA leakage and material corrosion. The fuel cell performance based on TLM exhibits a peak power density of 210 mW cm(-2) at 150 degrees C.