Incorporation of ammonium chloride (NH4Cl) with optimized Cornstarch: Poly vinyl pyrrolidone (80:20) polymer blend electrolytes were prepared by the technique of solution casting. XRD study reveals the incorporation of NH4Cl fully dissolved to make complexation to the polymer matrix. This complexation between polymer and salt was further confirmed by FTIR study by peak shifting and peak shape changing. Variation of asymmetry and symmetry stretching and vibration of cation (NH4+) were investigated by deconvoluted peak of FTIR in absorbance mode at O–H region and area of deconvoluted peaks in C–O region was changed by the increment of salt concentration in polymer blend electrolyte. It was used for the measurement of percentage of free ions and conduction ions. For 25 wt% NH4Cl-added polymer electrolyte system, there was 60.45% of free ions and also higher conductivity value of 1.53 × 10–6 S cm−1 at 303 K. The ion conduction in the polymer electrolyte is followed the overlapping large polaron tunnelling (OLPT) conduction model. From Arrhenius plot, conductivity of all the samples was linearly increased to follow the Arrhenius behaviour and low activation energy obtained was 0.151 eV for higher conducting sample. Dielectric studies confirmed the non-Debye nature and there was a existence of a shift in the relaxation peak towards the high frequency and thereby decrease in relaxation time.