Developing a Novel Polymer Composite Electrolyte (PVDF–PEO–LiNO ₃ /Li ₄ SiO ₄ ) for Lithium‐Ion Batteries

ABSTRACT This study reports on a polymer composite electrolyte composed of organic polymer PVDF–PEO–LiNO 3 (polyvinylidene fluoride, polyethylene oxide, and lithium nitrate) and an inorganic solid electrolyte, yttrium‐doped Li 4 SiO 4 , which exhibits high ionic conductivity (5.1 × 10 −5 S cm −1 ) to form a novel composite electrolyte for lithium‐ion batteries. The compound is synthesized through the solution casting method. The performance of ionic conductivity is analyzed using electrochemical impedance spectroscopy (EIS). The addition of 7.5% of yttrium‐doped Li 4 SiO 4 enhanced the ionic conductivity at room temperature to 3.88 × 10 −4 S cm −1 , and the membrane reached its highest conductivity range. Functional groups of molecules are obtained through FTIR. The thermal decomposition of materials is analyzed using TGA. The effect of solid electrolytes in a polymer matrix is characterized by XRD. A transference number of 0.982 is achieved for the PPY7 electrolyte. The decomposition of the electrolyte in the applied potential difference is obtained in LSV. The dielectric constant, loss, and relaxation time are characterized. SEM micrographs give information on the morphology and chemical composition percentage for the obtained samples. Cyclic voltammetry is carried out to obtain the electrochemical performance of PP and PPY7 samples.