Preparation of the PVA/HAP composite polymer membrane for alkaline DMFC application

A novel polyvinyl alcohol/hydroxyapatite (PVA/HAP) composite polymer membrane was prepared by the direct blend process and solution casting method. Glutaraldehyde (GA) was used as a crosslinker for the composite polymer membrane in order to enhance the chemical, thermal and mechanical stabilities and to reduce the swelling ratio. The characteristic properties of the PVA/HAP composite polymer membranes were examined by thermal gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), micro-Raman spectroscopy and AC impedance method. Alkaline DMFC, consisting of an air cathode electrode with MnO2 carbon inks, an anode electrode with PtRu black inks on Ti-mesh matrix and the PVA/HAP composite polymer membrane, was assembled and investigated. It was found that the alkaline DMFC using a novel cheap PVA/HAP composite polymer membrane showed good electrochemical performance at ambient temperature and pressure.

The composite polymer membrane based on PVA/HAP was obtained by a solution casting method. Alkaline air-breathing direct methanol fuel cell (DMFC) utilizing the PVA/HAP composite polymer membrane was assembled and systematically examined. The DMFC is comprised of the air cathode electrode with MnO2/ BP2000 catalyst inks, the PtRu black Ti-anode electrode and the PVA/HAP composite polymer membrane. It was demonstrated that the alkaline DMFC with the PVA/HAP composite polymer membrane shows good electrochemical performances at ambient temperatures and pressure. The maximum peak power density of the alkaline DMFC is 11.48 mW cmÀ2 at 25 C. From the application point of view, the PVA/ HAP composite polymer membranes can easily be prepared and controlled. These composite polymer membranes show a high potential for future alkaline DMFC applications.