Investigation lithium nitrate doping in PVA:CS blend polymer electrolytes for energy storage devices

High-performance Blend Polymer Electrolyte (BPE) based on Polyvinyl Alcohol/Chitosan (PVA:CS) are developed for energy storage devices utilizing a solution cast process with the lithium nitrate (LiNO₃) as a doping salt. LiNO₃ is an efficient material that enhances the conductivity of the prepared PVA:CS blend electrolytes with appropriate doping level. The observed optical and electrical properties of the prepared pure and doped electrolytes were investigated. The structural nature of the prepared samples analyzed by X-Ray diffraction (XRD) and FE-SEM. FTIR revealed that the functional group and their interaction between the pure blend and with doped salt. The analyzed electrical properties were performed through Electrical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CV). The BPE with 20 wt% LiNO₃ (BPE PCL2 sample) exhibited the highest ionic conductivity of 7.55 µS.cm⁻¹. In this sample, the highest conductivity showed unique oxidation and reduction peaks in cyclic Voltammetry (CV) curve that indicated non-faradaic process for the capacitive nature. Thermogravimetric analysis (TGA) revealed thermal stability up to 232 °C, and the BPE PCL2 sample showed electrochemical stability at 4.22 V, as observed in the I-V analysis, provides useful information about the electrochemical behavior with BPE PCL2 sample. This ensures cost effective energy storage devices.