Mechanochemical ball-milling process for manufacturing sulfide and halide solid electrolytes

The solid-state battery industry faces a production bottleneck that has nothing to do with chemistry: most high-conductivity sulfide and halide solid electrolytes can be synthesized cleanly in a lab but resist economical scale-up. Conventional solid-state firing routes require high-temperature furnace cycles, tightly controlled atmospheres across large batches, and grinding steps that reintroduce contamination — all of which drive up cost and limit throughput. Mechanochemical ball-milling collapses this problem into a single, continuously tunable unit operation. By driving mechanochemical energy input through carefully defined frequency and duration windows — 30 to 60 Hz for 4 to 48 hours — the same precursor binaries that require furnace synthesis under conventional routes can be converted directly into phase-pure electrolyte powders, with an optional low-temperature inert-atmosphere anneal (200–550 °C) available to complete crystallization or relieve mechanical disorder without the energy penalty of full solid-state firing. This invention protects the manufacturing process itself, not any single composition. That distinction is commercially significant: a process patent reads on every producer who mills these electrolyte families regardless of which specific formula or supplier they use. The claim covers the entire mechanochemical synthesis of both the sulfide family (represented by Na3PS4 and Li3PS4) and the halide family (represented by Li3InCl6 and Li3YCl6) — two electrolyte classes that are today among the most actively pursued materials in solid-state battery development. The portfolio of which this asset is a part — integrated packaging, storage, and PFAS-treatment systems — benefits from a manufacturing-process anchor that is orthogonal to composition patents: it creates a second enforcement dimension that composition-only filers do not have. The timing of this asset is well-matched to where the industry stands. Pilot-scale solid-state battery production lines are now being commissioned by several major cell manufacturers, and the mechanochemical route is broadly recognized as the most viable path to ton-scale halide and sulfide powder production. A process patent filed now, backed by measured conductivity data from the resulting compositions, positions the holder to engage suppliers, licensees, or battery manufacturers at the exact moment that manufacturing process selection is being locked in.

This is a process-type asset, which means the material science under protection is not a new crystal structure but rather the synthesis pathway that reproducibly yields several critical electrolyte compositions. The four representative members of the protected family are Li3InCl6, Li3YCl6 (both halide electrolytes), Na3PS4, and Li3PS4 (both sulfide electrolytes). Each of these materials has been validated independently as a high ionic-conductivity solid electrolyte, and the process claim asserts that the mechanochemical route described here produces them with the properties required for battery-cell use. The mechanochemical process window is defined by two primary parameters: milling frequency (30–60 Hz, corresponding to the vibrational energy delivered per unit time in a planetary or shaker mill) and total milling duration (4–48 hours). These bounds are not arbitrary — they delineate the zone in which mechanical energy input is sufficient to break and re-form the relevant ionic bonds without either under-reacting (leaving residual binary precursors) or over-milling into amorphous phases that carry poor conductivity. The optional anneal step, conducted at 200–550 °C under an inert atmosphere, is available when the as-milled powder retains sufficient disorder to benefit from thermal relaxation into a more ordered structure. For some compositions the anneal is unnecessary; for others it measurably increases conductivity by improving long-range order without crossing into the regime where sulfide volatility or halide decomposition become problems. The computational foundation for this asset is distinct from the structure-prediction work the organization performs on novel compositions. Here, the simulation evidence is grounded in two specific bodies of work: the Family Y mechanochemical process windows, which define the parameter space (frequency, time, precursor stoichiometry) within which phase-pure product reliably forms, and the OBELiX measured conductivity dataset, which provides experimentally derived ionic conductivity values for the electrolyte compositions produced by the process. This combination — parametric process mapping plus measured output properties — is the evidentiary core that supports the process claims. Because this is a manufacturing process asset rather than a structural materials asset, the multi-MLIP consensus phonon-stability framework that Lattice Graph applies to novel compositions is not the primary validation mechanism here; instead, the proof rests on process-yield and conductivity measurements that directly demonstrate functional output. The technical advantage of the mechanochemical route relative to conventional solid-state synthesis is multifaceted. Mechanochemical synthesis is inherently scalable in a way that Schlenk-line or glovebox solid-state firing is not. Ball mills can be run in continuous or semi-continuous modes, precursor loading is straightforward, and the process does not require the extended high-temperature dwell times that are energy-intensive and potentially damaging to sulfide compositions with volatile sulfur species. For halide electrolytes, which are often moisture-sensitive but not as aggressively so as sulfides, the milling-plus-anneal route also allows tighter control over lithium or sodium stoichiometry than furnace methods, because there is no vapor-phase loss of alkali species at the milling stage.

The addressable market for this asset is the supply chain serving solid-state battery cell manufacturers — specifically, the producers and toll-processors who supply solid electrolyte powders. Current estimates for the solid electrolyte materials market range from roughly $1 billion to $5 billion at the scale implied by near-term automotive and consumer electronics solid-state battery deployment, with the trajectory heavily dependent on how quickly several major cell manufacturers transition from pouch-cell lithium-ion to solid-state formats. These figures should be treated as estimates; the market is pre-commodity and actual volumes will be determined by which cell chemistries win at the system level. The relevant buyers of this process claim are solid-state battery material suppliers — companies that process raw precursors into battery-grade electrolyte powders and sell them to cell manufacturers. This category includes established chemical and ceramic companies that are entering the electrolyte powder business, as well as dedicated solid electrolyte startups. For these players, a scalable, documented, patent-protected manufacturing process has independent value beyond the composition: it gives them a defensible manufacturing position and reduces the risk that a competitor can freely copy their production approach once they disclose it through product launches or regulatory filings. A licensee of this process patent, combined with composition rights, would hold a substantially stronger position than a composition-only licensee. The royalty logic for a process patent in a materials supply chain typically attaches to the volume of electrolyte powder sold or to the production capacity installed. In a market where electrolyte powder might eventually trade at $10–50 per kilogram at scale (again, an estimate based on comparable ceramic functional materials), even a modest per-kilogram royalty on a multi-hundred-ton annual production run produces meaningful license revenue. Alternatively, the asset can function as a cross-licensing chip in negotiations with incumbents who have their own composition portfolios but lack a documented, claimed mechanochemical process window.

scalable mechanochemical route to halide/sulfide electrolytes

The most natural acquirers or licensees are solid-state battery material suppliers — companies in the business of producing battery-grade halide and sulfide electrolyte powders for cell manufacturers. This includes established chemical companies (including ceramic and specialty inorganic materials producers) that are building electrolyte powder divisions, as well as dedicated solid electrolyte startups that are transitioning from laboratory-scale synthesis to pilot production. For these players, acquiring or licensing a process patent with a documented, measured-output evidentiary record is directly accretive to their commercial and IP positions. A second buyer category is the cell manufacturers themselves — automotive OEM-affiliated battery ventures and independent solid-state battery developers — who are beginning to bring electrolyte powder production in-house to secure supply chain independence. For these entities, a process patent is both a defensive shield and a potential royalty source if they license it back to external suppliers. The asset is also attractive as a cross-licensing chip in negotiations with parties who hold halide or sulfide composition patents, since the composition holder and the process holder each have something the other needs to operate freely at scale.

The primary technical risk is that the process window claimed — while supported by compositional conductivity data — has not yet been demonstrated across its full parametric range in a scaled production setting. If a challenger were to show that the extremes of the claimed range (e.g., 30 Hz for 4 hours, or 60 Hz for 48 hours) produce off-spec product for certain electrolyte family members, it could provide grounds to narrow the claim during prosecution or post-grant review. The straightforward mitigation is to execute the yield-and-purity demonstration across the full window before the claim is tested adversarially, converting an open validation gate into a closed one. A secondary risk is the pace of competing filings. The mechanochemical synthesis of halide electrolytes in particular is an area of rapid academic and industrial activity, and process-specific patent filings are increasing. While the current FTO screen is clean, the landscape could shift with new grants. Continued monitoring of competitor filings — particularly from Japanese, Korean, and German battery material producers who are active in this chemistry — is warranted. The asset's strongest long-term defensive position is achieved by combining this process patent with composition coverage on the specific electrolyte members it produces, creating an interlocking claim structure that is considerably harder to engineer around.