Ambient in-plane Li-ion cell patterning via APPJ-assisted aerosol deposition of Ta-LLZO, LiFePO4, and graphite

An ambient, oven- and vacuum-free route is presented to pattern the active elements of an in-plane Li-ion micro-cell by coupling an atmospheric-pressure plasma jet (APPJ) with ultrasonic aerosol delivery. Ta-doped garnet (Ta-LLZO), graphite, and LiFePO₄ (LFP) are deposited as thin coatings on rigid glass using an APPJ clean–deposit–stabilize sequence with aqueous suspensions. Standoff, scan speed, hatch spacing, and pass count control line continuity and edge fidelity. Optical/SEM confirm continuous coatings and preserved alignment after multi-material sequencing. Ta-LLZO exhibits in-plane mottling at higher pass counts that is mitigated by reducing cycles. APPJ–aerosol route leverages plasma-assisted wetting to enable ambient patterning of narrow solid-electrolyte features. Because it uses sprayable aqueous suspensions, the method is, in principle, compatible with slurries formulated from direct-recycled powders, such as relithiated LFP. • Ambient APPJ–aerosol patterns in-plane Li-ion layers without vacuum or ovens. • Ta-LLZO line width and clearance controlled via standoff/scan/hatch/pass. • Mottling in Ta-LLZO was mitigated by reducing deposition cycles. • Complement for RT PAD/AD of ambient patterning from aqueous suspensions. • Suspension-based process compatible with direct-recycled LFP powders.