Solid polymer electrolytes (SPEs) will allow improving
safety and
durability in next-generation solid-state lithium-ion batteries (LIBs).
Within the SPE class, ternary composites are a suitable approach as
they provide high room-temperature ionic conductivity and excellent
cycling and electrochemical stability. In this work, ternary SPEs
based on poly(vinylidene fluoride-co-hexafluoropropylene)
(PVDF-HFP) as a polymer host, clinoptilolite (CPT) zeolite, and 1-butyl-3-methylimidazolium
thiocyanate ([Bmim][SCN])) ionic liquid (IL) as fillers were produced
by solvent evaporation at different temperatures (room temperature,
80, 120, and 160 °C). Solvent evaporation temperature affects
the morphology, degree of crystallinity, and mechanical properties
of the samples as well as the ionic conductivity and lithium transference
number. The highest ionic conductivity (1.2 × 10–4S·cm–1) and lithium transference number (0.66)
have been obtained for the SPE prepared at room temperature and 160
°C, respectively. Charge–discharge battery tests show
the highest value of discharge capacity of 149 and 136 mAh·g–1at C/10 and C/2 rates, respectively, for the SPE
prepared at 160 °C. We conclude that the fine control of the
solvent evaporation temperature during the preparation of the SPE
allows us to optimize solid-state battery performance.