Ternary composites of poly(vinylidene fluoride-co-hexafluoropropylene) with silver nanowires and titanium dioxide nanoparticles as separator membranes for lithium-ion batteries.

[Display omitted] • Ternary composite membranes have been developed for battery separator applications. • Membranes have been developed by varying silver nanowires and titanium dioxide nanoparticle content. • Ternary composites show improved mechanical and electrochemical responses. • An ionic conductivity > 10−4 S/cm has been obtained independently of the filler type and content. • The highest discharge capacity value has been obtained for the 5 wt% AgNWs/5 wt% TiO 2 /PVDF-HFP membranes. In the realm of polymer composites, there is growing interest in the use of more than one filler for achieving multifunctional properties. In this work, a composite separator membrane has been developed for lithium-ion battery application, by incorporating conductive silver nanowires (AgNWs) and titanium dioxide (TiO 2) nanoparticles into a poly(vinylidene fluoride- co -hexafluoropropylene) (PVDF-HFP) polymer matrix. The composite membranes were manufactured by solvent casting and thermally induced phase separation, with total filler content varying up to 10 wt%. The ternary composites composites present improved mechanical characteristics, ionic conductivity and lithium transfer number compared to the neat polymer matrix. On the other hand, the filler type and content within the composite has little bearing on the morphology, polymer phase, or thermal stability. Once applied as a separator in lithium-ion batteries, the highest discharge capacity value was obtained for the 5 wt% AgNWs/5 wt% TiO 2 /PVDF-HFP membrane at different C-rates, benefiting from the synergetic effect from both fillers. This work demonstrates that higher battery performance can be achieved for next-generation lithium-ion batteries by using separator membranes based on ternary composites. [ABSTRACT FROM AUTHOR]