Fabrication and Electrochemical Properties of All Solid State Lithium Battery Based on PVA-PVP Polymer Blend Electrolyte

摘要

All Solid State Lithium Polymer Batteries (LPBs) have been fabricated by using solid polymer blend electrolyte (SPE) composed of biodegradable polymers, polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) blend with lithium perchlorate LiClO_4 at a different weight percent ratio. The effect of addition of lithium salt with blend polymers is investigated by XRD, FTIR, Electrochemical impedance (EIS), and Cyclic Voltammetry measurements as well as the charge-discharge performance. The room temperature electrolytic conductivity of the order of 10~(-4) S cm~(-1) has been achieved in the composition of 70PVA: 30PVP: 25 Wt % LiClO_4. The conductivity-temperature plot is found to follow the Arrhenius nature, which showed the decrease in activation energy with the increasing salt concentration. The electrolyte with the highest ion conductivity has been used in the fabrication of Lithium/Polymer battery with the configuration of Li (metal foil)/SPE/LiCoO_2. The galvanostatic charge/discharge performance is carried out from 3 to 4.6 V versus Li~+/Li. The electrochemical stability of the polymer blend electrolyte membrane has been found to be stable up to ～4.6 V versus Li/Li~+.