Conductivity Studies of PVA:PVP based NH4Cl Polymer Electrolytes Prepared by Solution Casting Technique

Here, we synthesize a new type of composite electrolyte by blending PVA (Mw = 140000 g/mol) and PVP (Mw = 40000 g/mol) in 50:50 wt%, then adding the relatively high concentration of various mass ratio adopted salt NH₄Cl from 5-30%. The structural, vibrational, morphological, and conductance studies of the prepared polymer electrolytes are analysed in detail. X-ray Diffraction (XRD) results proved that due to introducing ammonium chloride into the polymer blend, crystallinity of its sample decreased. The Fourier transform infrared spectroscopy (FTIR) analysis has identified the complexation of the polymer blend electrolyte and salt. The morphological studies by Scanning Electron Microscopy (SEM) images clearly indicate the improvement in morphology; this occurs because of dissolving the solution within the polymer. The calculation of Ionic conductivity of the polymer electrolyte has been done by the analysis of AC Impedance spectroscopy. The maximum conductivity of 1.05 x 10⁻⁵ Scm⁻¹ has been found in the composition of 50PVA:50PVP:20wt.% of NH₄Cl. This work introduces a targeted compositional engineering strategy for PVA/PVP polymer electrolytes by systematically tuning the NH₄Cl loading in an equimolar polymer blend to realize enhanced proton transport, a salt system that remains underrepresented relative to other ammonium-based electrolytes. Beyond conductivity enhancement, the study elucidates the interdependence between induced amorphization, polymer–salt coordination dynamics, and surface morphological evolution, demonstrating that a critical NH₄Cl concentration of 20 wt.% yields an optimal transport network. The findings provide mechanistic insight into composition–structure–property relationships governing proton conduction in PVA/PVP-based electrolyte platforms.