Ion dynamics and positron annihilation studies on polymer ceramic composite electrolyte system (PVA/NaClO4/Y2O3): Application in electrochemical devices

摘要

? 2022 Elsevier Ltd and Techna Group S.r.l.This study aimed to develop a framework to investigate the structural, dielectric, and transport properties of a sequence-based PVA matrix polymer ceramic composite electrolyte system with sodium perchlorate (NaClO4) and yttrium oxide (Y2O3) as nanofillers. The XRD results revealed a change in crystallinity. Chemical interactions between the PVA/NaClO4 matrix and yttrium ions were revealed using FTIR studies. From SEM studies, the morphology was observed to be smoother, homogeneous, and coherent for the pure+salt PCCE system after addition of Y2O3 nanoparticles to the matrix. In Py3 system, the nanoparticles were randomly linearly aligned due to inter- and intramolecular bonding. The elemental composition and mapping were confirmed by the presence of Y2O3 and NaClO4 particles. For 7 wt, 1 wt Y2O3 nanoparticle loading (Py7, Py1) in the PCCE matrix, the positron lifetime parameters o-Ps lifetime (τ3) and free volume size (Vf) showed a minimum (Py7) and maximum value (Py1). Between these two values, the value for Py3 was ascertained. It was found that Py3 was least crystalline with highest ionic conductivity 3.25 × 10?4 S/cm which is strongly influenced by the highest charge concentration (n), not its mobility (μ). The highest conducting sample (Py3) had an ion transference number (tion) of 0.919, indicating that the current system was ion-dominant with a small amount of electron participation. The LSV technique determined the potential window for the Py3 PCCE system to be 3 V, indicating that it could be used in energy storage applications. The proposed PCCE system's open circuit voltage was 1.7 V, and the discharge characteristics of a primary sodium battery built with a high-conductivity electrolyte system (Py3) were thoroughly examined. To ensure the safety of our prepared energy storage systems, we tested films for flame retardancy and dimensional stability. Py3 film demonstrated considerable flame retardation that was stable over several ignitions. Self-extinguishing time for pure+salt displays ? 41 s g?1 whereas in the case of Py3 PCCE it has a value ? 6 s g?1.