Fabrication of\nZinc Metal Organic Framework-Embedded\nElectrolyte Membranes Comprising Sulfonated Poly(ether ether sulfone)\nand Polyimide for Fuel Cells

This work focuses on the design and\ndevelopment of membranes\nwith\nconstructive physicochemical and electrochemical properties for fuel\ncell applications. Herein, novel electrolytes are prepared by blending\nsulfonated poly(1,4-phenylene ether ether sulfone) (sPEES) with polyimide\n(PI). To improve the ion-conducting properties, a zinc metal organic\nframework (Zn-MOF) is synthesized via solvothermal and sonochemical\nmethods. From the XRD data, the average crystallite size of the prepared\nMOF is found to be ∼27.8 nm. For the preparation of composites,\nZn-MOF is embedded in the blend matrix, and various synthesis parameters,\nsuch as reaction temperature, filler loading, and casting time, were\noptimized. Among the composites, the 3 wt % Zn-MOF-sPEES/PI membrane\ndisplays an ion-exchange capacity value of 1.31 mEq/g, an ionic conductivity\nof 0.0811 S/cm at 80 °C, and a maximum peak power density of\n437 mW/cm<sup>2</sup> with a cell voltage of 0.72 V. In summary, the\nexperimental results affirm that the synthesized electrolytes are\nwell-suited for applications in hydrogen–oxygen fuel cells.