Electrical properties of Mg2+ ion-conducting PEO: P(VdF-HFP) based solid blend polymer electrolytes

Mg2+ ion-conducting solid blend polymer electrolytes (SPEs) based on PEO: P(VdF-HFP) are prepared by solution casting technique using DMF as solvent. The X-ray diffraction analysis (XRD) confirms the decrease in crystalline phase of polymer electrolytes due to the addition of salt. The complex formation between polymers and salt is confirmed by Fourier transform infrared spectroscopy (FTIR) analysis. Morphological analysis shows the existence of interconnected micro-pores that enhances the mobility of Mg2+ ions. The polymer electrolyte (PEO:P(VdF-HFP): MgBr2)(90:10:15) has higher ionic conductivity of 3.90 x 10(-4) S/cm at room temperature. For all solid blend polymer electrolytes, the total ionic transference number has been observed to be 0.98-0.99 range. The polymer electrolytes exhibit maximum electrochemical stability of 1.86 V. The cyclic voltammetry (CV) performance of the prepared EDLC reveals the increase in specific capacitance as the scan rate decreases. According to charge-discharge studies, the cyclic retention of the EDLC is maintained to be similar to 84.2% even after 500 cycles.