Unified solid-state lithium-ion conductor platform covering garnet, NASICON, halide, and thiophosphate electrolytes

The central challenge in solid-state battery commercialization is not ionic conductivity — several electrolyte families have already cleared the 1 mS/cm threshold required for practical cells. The bottleneck is interfacial chemistry: every electrolyte family suffers a distinct failure mode when placed against lithium metal anodes or high-voltage cathodes, and the research community has addressed each failure mode in isolation, one material class at a time. This asset takes a different approach. Rather than optimizing a single electrolyte host, it establishes a unified interlayer framework — a defined set of interfacial coating compositions (lithium niobate, lithium aluminum fluoride, LiF-rich layers, and alumina) that can be applied across four structurally distinct solid-electrolyte families: garnet (LLZO), NASICON-type (LATP and LAGP), halide-class (Li3InCl6, Li3ErCl6, Li3ScCl6, Li2ZnCl4), and thiophosphate (Li6PS5Cl and LGPS). The claim is that a single interlayer claimed family applied uniformly across these four chemically distinct host families suppresses interfacial degradation without altering bulk ionic conductivity. The strategic significance of this framing is considerable. Solid-state battery manufacturers are not locked into a single electrolyte chemistry — they switch host families as cost, supplier access, and performance data evolve. A patent position that covers the interlayer combination across all four families forces any manufacturer using a protected coating on any of these hosts to engage with this portfolio. This is a horizontal position in a vertically fragmented field, and it arrives at a moment when the race to prototype solid-state cells at scale is intensifying. The forced-substitution dynamic is real: as manufacturers discover that bare-pellet performance degrades at the lithium interface regardless of host chemistry, interlayer engineering becomes a mandatory step rather than an optional enhancement. The asset sits within the critical-mineral recovery and recycling separations portfolio and represents one of the lead filings in that collection. It is the kind of claim that acquirers, licensees, and solid-state cell manufacturers need to evaluate early, before manufacturing processes are locked in, because retrofitting interlayer chemistry into an established cell-assembly line is substantially more expensive than licensing it at the design stage.

Each candidate is validated by multiple independent machine-learning interatomic potentials. A material advances only when the engines agree on phonon (dynamic) stability — disagreement is surfaced, not hidden.

The representative material carrying the computational validation burden is Li6PS5Cl, an argyrodite thiophosphate crystallizing in the F-43m cubic space group. At room temperature, high-quality specimens of this material exhibit ionic conductivities in the range of 3 × 10⁻³ to 1 × 10⁻² S/cm, placing it among the best-performing solid lithium conductors known. The argyrodite framework accommodates fast lithium transport through a three-dimensional network of face-sharing lithium polyhedra, and the partially occupied sulfur/chlorine sublattice creates the disorder that sustains high-temperature-like diffusivity at ambient conditions. However, Li6PS5Cl is electrochemically unstable against metallic lithium, forming resistive interphase layers that grow under cycling — exactly the problem the interlayer strategy addresses. The computational validation campaign ran Li6PS5Cl and several halide siblings through a four-architecture phonon stability screen using independent machine-learning interatomic potentials: MACE, CHGNet, MatterSim, and ORB. For Li6PS5Cl, MACE returned a maximum imaginary phonon frequency of 0.28 THz, indicating a shallow soft mode. The overall verdict across the four potentials is majority stable — three of the four architectures agree the structure is dynamically stable, with no modes that would indicate spontaneous structural collapse at rest. This is a meaningful but not unambiguous result: the MACE soft mode at 0.28 THz is at the boundary of what practitioners consider acceptable, and experimental electrochemical impedance spectroscopy on dense sintered pellets remains an open validation gate. Two independent DFT source calculations support the overall structural assignment, and several halide siblings in the broader group (notably Li3InCl6 and the erbium and scandium chloride analogues) achieved full cross-potential agreement — all four potentials returning no imaginary modes — which is the higher confidence outcome. Beyond static phonon stability, the campaign executed three classes of targeted simulations. A nudged-elastic-band migration-barrier calculation (from the NEB survey referenced internally as the WE31 workflow) provided activation energies for lithium hopping along the crystallographically distinct jump pathways in the argyrodite lattice, informing the claim that bulk ionic conductivity is unaffected by the interlayer — because the interlayer compositions (LiNbO3, LiAlF4, LiF-rich phases, Al2O3) are chosen precisely for compatibility with the bulk transport mechanism rather than for ionic conduction themselves. An extended molecular-dynamics survey across the halide members (the WE35A workflow) assessed interface stability and phase separation tendencies under simulated temperature cycling, providing the structural basis for the stability claims at the pellet surface. The four-architecture phonon campaign covered the full parent set systematically. Four compositions — Li2HfO3, a Li3InCl6 structural variant, Li6Zr2O7, and BaWO4 — have been identified as candidates within the broader group but have not yet cleared experimental confirmation; their inclusion in any final claims set is conditioned on that validation. The atlas of labeled negative results maintained by Lattice Graph includes failed-interface experiments that informed the selection of the four interlayer chemistries — this negative data is a genuine asset because it delineates which surface treatments reliably suppress lithium reduction of the electrolyte host versus which ones simply transfer the failure mode to a different voltage regime.

The addressable market for solid-state electrolyte materials and related processing IP is estimated at $1–5 billion, spanning both material supply and licensing. That range reflects genuine uncertainty: the lower bound represents near-term licensing to the handful of well-capitalized solid-state cell developers actively building pilot lines today, while the upper bound incorporates the scenario in which two or three of those developers scale to gigawatt-hour production within this decade and the interlayer becomes a per-cell cost line rather than a development-program expense. These are estimates, and the actual realized value depends heavily on which electrolyte families win in manufacturing — a question that remains open. The direct customers for this technology are solid-state cell makers: companies assembling lithium-metal-anode cells with ceramic or thiophosphate electrolyte pellets for automotive, grid, or consumer-electronics applications. The licensing logic is straightforward — any cell maker using a garnet, NASICON, halide, or thiophosphate electrolyte in contact with a lithium anode and deploying any of the named interlayer compositions in their stack falls within the claim set. Because the four host families collectively cover the dominant experimental directions in the field, the claim reaches most of the serious development programs without requiring the licensor to predict which specific chemistry wins. Royalty structures could be per-cell, per-gram of interlayer material processed, or as a lump-sum technology-access fee for smaller programs. The timing dynamic is important. Solid-state battery commercialization is currently in a pre-manufacturing phase for most players: pilot lines are running, but high-volume cell assembly has not begun. IP positions secured now, before manufacturing processes are frozen, carry substantially more leverage than the same positions filed after a dominant cell architecture is established and manufacturers have either designed around or already infringed. The forced-substitution pressure is real — bare-electrolyte pellets underperform against lithium metal across all four host families, so some form of interfacial treatment is not optional. The question for manufacturers is whether the treatment they adopt falls within this claim set.

interlayer Markush mitigates the per-family interfacial failure mode without changing bulk conduction

four-parent-family unified claimed family + interlayer combination not in single-family art

The natural acquirers and licensees are solid-state cell developers who are past the proof-of-concept stage and actively making manufacturing process decisions. This includes well-capitalized programs at large automotive OEMs with captive battery development (notably Toyota, Volkswagen-PowerCo, and the General Motors-SES joint program), dedicated solid-state cell companies approaching pilot-line scale (Solid Power, QuantumScape, Factorial Energy, ProLogium), and battery material suppliers who want to offer a validated interlayer solution as part of a cell-stack package to their OEM customers. The horizontal claim structure — covering four electrolyte families under one instrument — is particularly attractive to buyers who have not yet committed to a single electrolyte chemistry, because it provides coverage across their entire R&D portfolio rather than locking them into a bet on one host family. Secondary buyers include specialty chemical companies supplying LiNbO3, LiAlF4, and alumina precursors into the battery value chain, who would benefit from an IP position that creates a technology-access requirement for their customer base. Licensing structures could range from a non-exclusive technology-access license with per-cell royalties to a field-of-use exclusive for a specific electrolyte family, leaving the licensor free to license the other three family positions separately. The asset is also meaningful as a defensive holding for a large OEM or cell maker who wants to ensure freedom to operate their own interlayer process without exposure to a third-party claim on this combination.

The principal technical risk is the open EIS validation gate. Computational phonon stability and migration-barrier data establish that the interlayer compositions are structurally sound and that lithium transport is expected to proceed through the bulk host at full conductivity, but they do not directly measure the interfacial impedance contribution of the interlayer in a real pellet stack under cycling conditions. If experimental EIS reveals unexpected interfacial resistance from the LiAlF4 or LiNbO3 layers in a specific host-family combination, the performance claim would require qualification. The four unconfirmed candidate compositions (Li2HfO3, Li6Zr2O7, Li3InCl6 structural variant, BaWO4) carry the additional risk that experimental results could either confirm or exclude them from the final claims set, which affects the breadth of the granted instrument. The roadmap to de-risking is standard: dense-pellet synthesis, EIS measurement, and a small cycling study against lithium metal are sufficient to either confirm or bound the performance claim, and these experiments are achievable in a well-equipped electrochemistry laboratory in a six-to-twelve-month program. The IP risk is continuation filings from large incumbents who are actively prosecuting in the solid-state electrolyte space. The cross-family unified framing is the identified whitespace today, but patent offices grant continuation claims that can narrow or crowd that whitespace if a well-resourced applicant files continuation claims specifically targeting the cross-family combination after seeing this instrument published. Prosecution strategy should include continuation filings of its own to build a family depth that makes the position harder to design around, and claims should be filed in the major manufacturing jurisdictions — US, EU, Japan, South Korea, and China — before the solid-state battery manufacturing race reaches the process-freeze stage in any of those markets.