Research Of Intermediate-low Temperature Polymer Electrolyte Membrane Fuel Cell

Fuel cell is an electrochemical power generation appliance,which could directly convert chemical energy such as hydrogen energy to electrical energy.Fuel cell has many advantages such as environment friendly,sustainable and high efficiency,thus it is a candidate for the next generation.In recent years,the development of fuel cell has attracted wide attention around the world.Polymer electrolyte membrane fuel cell（PEMFC）is one kind of the fuel cells.Meanwhile the polymer electrolyte is the key for PEMFC.In this manuscript,a variety of polymer electrolyte membranes were prepared by the raw materials of polybenzimidazole（PBI）,quaternized polysulfone,and the two-dimensional inorganic materials of graphite oxide and Mxene.Subsequently,the physical and chemical properties of the membranes were studied.Firstly,the two-dimensional inorganic material of graphite oxide was synthesized,and a PBI/GO/PBI three layer composite proton exchange membrane was prepared.The structure were characterized by X-ray diffraction,field emission scanning electron microscopy,infrared spectroscopy and other devices.At 150℃,the mechanical strength of PBI/GO/PBI composite film is about two times that of the pure PBI film,whichi indicates that the mechanical stability of the PBI/GO/PBI three layer composite proton exchange membrane is greatly increased.The maximum tensile fracture length of the PBI/GO/PBI three layer composite proton exchange membrane is less than the pure PBI film,which means the PBI/GO/PBI three layer composite PEM may have a longer operational life.The maximum value of proton conductivity and the maximum power density of PBI/GO/PBI composite film were 0.0138Scm^-1 and 213mWcm^-2,respectively,which are higher than that of pure PBI membrane.In this manuscript,the two-dimensional ceramic materials Mxene,whose surface carries a large number of functional groups,were prepared from MAX by etching it of hydrofluoric acid.The PBI/Mxene composite membrane was prepared.The Mxene and PBI/Mxene composite membrane were characterized by using X-ray diffraction technique,X-ray diffraction,field emission scanning electron microscopy and infrared spectroscopy.Lastly,the basic properties of the membrane were tested.Compared the pure PBI membrane and the PBI/Mxene membrane at 150℃,the mechanical strength of the composite membrane was much higher.Also,the proton conductivity and power density of PBI/Mxene were improved,when the Mxene was added.The noble catalysts were normally used in PEMFC,which leading to a high cost.Recent years,the research on alkaline anion exchange membrane fuel cell has become a hot topic in academia,because the non-noble catalysts were permitted.At the end of this manuscript,the quaternary ammonium polysulfone（QPSU）monomer was prepared by the chlorination reaction and the quaternary ammonium reaction.The Mxene were filled with QPSU to prepare the QPSU/Mxene anion exchange membrane.The structure of the QPSU/Mxene membrane was characterized by using nuclear magnetic resonance technique and field emission scanning electron microscopy,and the physical and chemical properties of the QPSU/Mxene membrane was tested.The result exhibited that the DC date of the QPSU membrane was 1.17 g cm^-3,and the ionic conductivity of the QPSU/Mxene composite film was higher than that of pure QPSU in the alkaline environment,which was reached 53 mS cm^-1.