Magnesium ion conducting PVB-PMMA blend polymer electrolytes: Comprehensive structural, dielectric and electrochemical investigation

In this study, innovative polymer electrolyte membranes (PEMs) were developed using a Poly vinyl Butyral PVB/PMMA Poly(methyl methacrylate) blend doped with magnesium trifluoromethanesulfonate (Mg(CF 3 SO 3 ) 2 ) through the solution casting technique by varying polymers. Comprehensive structural and morphological studies were conducted using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Structural evaluations confirmed the successful integration of (Mg(CF 3 SO 3 ) 2 ) within the polymer matrix, strengthening its amorphous nature and polymer-salt interactions. Impedance spectroscopy was used to examine the electrical characteristics and ionic conductivity at frequencies up to 10 MHz. Additionally, dielectric characteristics such as modulus ( M ′ and M ′ ′ ), relaxation time (τ) and ion transport properties were investigated. Ion migration was identified as the main source of conductivity by the frequency-independent plateau in the AC conductivity profile. The synergistic interaction between 50%PVB:20%PMMA complemented by the ionic contribution from Mg(CF 3 SO 3 ) 2 salt that highlighted the highest ionic conductivity (2.16 ×10 −4 S/cm) and least activation energy. The potential of these advanced polymer electrolytes is used in next-generation solid-state batteries and electrochemical applications.