Nanocrystalline filler induced changes in electrical and stability properties of a polymer nanocomposite electrolyte based on amorphous matrix

An ion conducting polymer nanocomposite electrolyte (PNCE) series of film based on an amorphous polymer host (PMMA)–lithium salt (LiClO₄) complex dispersed with nanocrystalline yttria stabilized zirconia (n-YSZ) is reported. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analysis have confirmed feasibility of interaction among composite components (i.e. polymer–ion–filler). Ions in the PNCE matrix are present in the form of both free cations/anions as well as contact ion pairs and their concentration depends on filler loading in the matrix. Electrical conductivity enhancement on n-YSZ dispersion occurs by ~2 orders of magnitude at 30 °C and by ~5 orders of magnitude at 100 °C when compared with room temperature conductivity of the undispersed polymer salt (PS) film. The highest achieved conductivity value is ~1.3 × 10⁻⁴ S cm⁻¹ at 100 °C for 2 wt% n-YSZ. An excellent correlation between variation of d.c. conductivity and free mobile charge carriers versus filler loading has been observed. This correlation has been attributed to filler-induced polymer–ion–filler interaction. These evidences have formed the basis to propose a mechanism for ion transport.