Sodium-ion-conducting solid polymer electrolyte: temperature-dependent ionic parameters and solid-state polymer battery fabrication

Temperature-dependent ionic parameters and solid-state polymer battery studies of a newly synthesized sodium-ion-conducting solid polymer electrolytes (SPEs): (1 − x) PEO: x NaCl, where 0 ≤ x ≤ 50 in wt%, are reported. The present SPEs are synthesized by a recently developed hot-press/dry technique in place of traditional solution-cast method. The room temperature conductivity (σ) of the optimum conducting composition (OCC), i.e., (70PEO:30NaCl) is ~ 4.5 × 10–6 Scm−1. The ion transport behavior has been explained with the help of some basic ionic parameters viz. ionic conductivity (σ), ionic mobility (μ), mobile ion concentration (n), ionic transference number (tion) and ionic drift velocity (vd) by using various experimental as well as theoretical models. The conductivity enhancement and polymer–salt complexations have been confirmed by X-ray diffraction, differential scanning calorimetric and thermogravimetric analysis. A new solid-state polymer battery is also fabricated by using the optimum conducting composition of solid polymer electrolyte (SPE OCC) as an electrolyte, and their cell parameters have been calculated at room temperature.