Scalable manufacturing of hybrid solid electrolytes with interface control.

Hybrid solid electrolytes are promising alternatives for high energy density, metallic lithium batteries. Scalable manufacturing of multi-material electrolytes with tailored transport pathways can provide an avenue toward controlling Li stripping and deposition mechanisms in all solid state devices. A novel roll-to-roll compatible coextrusion device is demonstrated to investigate meso-structural control during manufacturing. Solid electrolytes with 25 wt.\% and 75wt.\% PEO-LLZO compositions are investigated. The co-extrusion head is demonstrated to effectively process multi-material films with strict compositional gradients in a single-pass. Average manufacturing variability of 5.75± 1.2 μm is observed in the thickness across all the electrolytes manufactured. Coextruded membrane with 1 mm stripes shows the highest room temperature conductivity of 8.8x10 S cm compared to the conductivity of single material films (25 wt.%:1.2x10 S cm , 75 wt.%:1.8x10 S cm ). Distribution of relaxation times and effective mean field theory calculations suggest that the interface generated between the two materials possess high ion-conducting properties. Computational simulations are used to further substantiate the influence of macro-scale interfaces on ion transport.