Water‑Based Microdroplet Spray for On‑Demand Lithium Metal Films and Nanoparticles

Battery makers and advanced materials teams struggle to deposit lithium metal or lithium nitride on substrates without costly dry‑room infrastructure, vacuum systems, or pyrophoric handling—slowing scale‑up and raising scrap and safety risk. This technology uses a water‑containing microdroplet spray to deposit lithium salt microdroplets onto a surface. Compared to vacuum evaporation or anhydrous electroplating, the approach is expected to lower capital and operating cost, simplify EH&S controls, enable direct‑write patterning, and tune morphology (nanoparticles, films, or dendrites) for performance and throughput. Current evidence comes from benchtop electrospray deposition with TEM/EELS/EDS confirming metallic Li and Li₃N in the deposits under ambient conditions. If proven at tool scale, manufacturers could speed electrode prelithiation, create protective interlayers for solid‑state cells, and produce catalyst‑grade Li materials with fewer steps and less specialized infrastructure. 

Technology Validation:

In benchtop electrospray deposition under ambient conditions, substrates coated from aqueous lithium‑salt sprays produced Li‑ and N‑containing nanoparticles; TEM/EDS mapped composition, and EELS resolved the Li K‑edge consistent with metallic lithium, with additional features consistent with Li halides/oxides. Adjusting spray potential shifted morphology from ~8–9 nm spheroidal particles to dendritic structures; Li₃N signatures were associated with the smaller nanoparticle fraction. 

Advantages:

- Ambient, water‑based processing: avoids vacuum and ultra‑dry anhydrous lines typical of lithium handling (expected cost and EH&S simplification). 

- Direct‑write & patternable deposition: steered spray enables films, features, or coatings on conducting or non‑conducting substrates. 

- Tunable morphology: process conditions yield nanoparticles, continuous films, or dendrites to optimize surface area vs. density. 

- Integration‑ready: conceptually compatible with inline or roll‑to‑roll spray tools for electrode or catalyst coating.

- Feedstock flexibility: uses commodity lithium salts rather than molten metal or organolithium reagents.

Applications:

- Anode prelithiation for next‑gen Li‑ion and solid‑state cells (coating current collectors or pre‑forming interlayers).

- Protective/interfacial lithium layers in solid‑state batteries to improve interfacial contact (lab‑scale pathway indicated). 

- Patterned lithium features for microbatteries and thin‑film cells where direct‑write simplifies fabrication. 

- Catalyst‑grade Li/Li₃N nanoparticles for ammonia synthesis or other Li‑mediated chemistries (early evidence aligns with Li₃N formation).

TRL: 3

Intellectual Property:

Provisional-Gov. Funding, 2025-06-13, United States