Spraying Li₆PS₅Cl and silver-carbon multilayers to facilitate large-scale fabrication of all-solid-state batteries

In recent years, solid-state battery (SSB) performance has steadily improved with the use of sulfide solid electrolytes (SEs). However, most research has focused on small (diameter <10 mm), thick (separator >500 μm) pellet-type cells that use non-scalable manufacturing routes and yield a low cell energy density. Technical applications require thinner and larger sheet-type cells made by scalable techniques. We examine the applicability of a scalable layer-by-layer spray printing approach for manufacturing sheet-type SSB components. Sprayed sulfide SE separators with thickness as thin as 10 μm and high ionic conductivity of 1 mS cm⁻¹ are fabricated, along with a sprayed composite cathode that delivered a capacity retention of 63% after 800 cycles. Finally, the flexibility of spray printing for process integration is demonstrated by the fabrication of an anode-free cell consisting of a sprayed Ag-C layer and a sprayed SE layer.