Role of LLZO dispersion in ion migration property of a ceramic integrated polymer composite electrolyte

Abstract

The present work focuses on the structural, electrical, dielectric properties, transport properties, and ion dynamics of a polymer-salt-ceramic composite within a range of “ceramic-in-polymer” to “polymer-in-ceramic.” The polymer-salt-ceramic composite has been prepared using a solution cast method with PEO, LiCF₃SO₃, and different wt% of a cubic-LLZO ceramic. The lower 2θ shifts of PEO, X-ray diffraction peaks and prominent changes in CH₂ and C-O-C bond profile in the FT-IR spectra verify the Lewis acid-base interaction between ceramic filler and a polymer salt complex. Anion and ion pair peak profiles indicate an enhanced ion dissociation effect at 20 wt% ceramic loading in the polymer-salt-ceramic composite. Further, the highest room temperature DC conductivity of ~5.25 × 10⁻⁵ S/cm has been achieved for the same optimized composite sample. The relaxation and diffusion parameters indicate a faster ion migration facilitated by high ion dissociation at this optimum ceramic loading. Furthermore, the voltage and thermal stability of the polymer-salt-ceramic composites are significantly improved w.r.t. pristine polymer and polymer salt complex systems. The current study examines how C-LLZO can enhance ion migration and salt dissociation, as well as how these two processes together can affect DC conductivity measurements and other stability characteristics.