Polymeric blends of poly(methyl methacrylate)/poly(vinylidene fluoride) (PMMA–PVDF) were prepared by solvent blending and analyzed for dielectric loss, dielectric modulus, thermal properties, and spectral analysis. The X-ray diffractometry provides prominent peaks at 20.15° and 81.81°, representing the polymeric gel electrolyte. The maximum degradation of the polymer occurs between 392.65 and 472.65 °C. The PMMA–PVDF electrolyte shows high thermal stability for various applications. The percentage relative crystallinity of the PMMA–PVDF polymer blend is 7.37%, indicating the reduction in crystallinity of the electrolyte. The crystallinity reduction of the polymer improves the polymer blend properties. The scanning electron images reveal that the two polymers have blended uniformly, and the pores have reduced. The PMMA–PVDF polymer electrolyte exhibits a higher dielectric constant than pure polymers. They possess high chemical stability, thermal stability, and dielectric properties suitable as electrolytes in high-performance flexible batteries.