A novel development of biomaterial membrane based on Peltophorum pterocarpum—a flower with various concentrations of ammonium thiocyanate (NH₄SCN)—is prepared with distilled water as a solvent by using solution casting technique. The prepared membranes are subjected to different characterization techniques such as X-ray diffraction analysis, differential scanning calorimetry, AC impedance analysis, transference number measurement, and linear sweep voltammetry. The crystalline/amorphous nature of the prepared biomaterial membrane is studied by using XRD. The T_g values of the prepared membranes are analyzed using differential scanning calorimetry. The highest ionic conductivity is found to be 2.19 × 10⁻² S/cm for 1 g PP with 0.7 M wt% NH₄SCN by AC impedance analysis. The highest ion-conducting biomaterial membrane of 1 g Peltophorum pterocarpum with 0.7 M wt% NH₄SCN is observed with an electrochemical stability of 2.00 V from LSV. Primary proton battery and proton exchange membrane (PEM) fuel cell are fabricated using the highest ion-conducting biomaterial membrane. The open-circuit voltage (OCV) of primary proton battery is observed to be 1.57 V, and its performance is studied. A single fuel cell is constructed, which exhibits a cell potential of 487 mV.