Molybdenum-modified Li7P3S11 sulfide electrolyte with enhanced ionic conductivity

The solid-state battery electrolyte field is under intense commercial pressure to replace liquid lithium-ion electrolytes with materials that are safer, more energy-dense, and processable at scale. Sulfide-based electrolytes have emerged as the leading candidate class for near-term commercialization because their room-temperature ionic conductivity can approach or exceed that of liquid electrolytes, they are soft enough to cold-press without sintering, and they can be manufactured in dry-room conditions compatible with existing lithium-ion production lines. Within the sulfide family, Li7P3S11 glass-ceramic is one of the highest-performing parent compositions, routinely achieving conductivities in the 1-3 mS/cm range — yet commercial cell developers need every incremental gain they can extract, because electrolyte resistance directly caps power density and rate capability in the solid-state cell stack. This invention covers molybdenum-modified Li7P3S11 at controlled additive fractions (0.1-15 mol% Mo) targeting room-temperature ionic conductivity at or above 2 mS/cm, with a computational warehouse benchmark of approximately 4.8 mS/cm — roughly 2-3 times the conductivity of the undoped parent compound. The commercial proposition is straightforward: any electrolyte formulation that can demonstrably double or triple lithium-ion throughput at room temperature, with a clean freedom-to-operate position, becomes an immediately licensable composition for sulfide cell developers who are currently optimizing around the parent material. The invention sits within the broader "solid-state battery electrolytes and interfaces" portfolio, where it functions as the lead entry in the transition-metal-doped Li7P3S11 family. The timing argument is grounded in forced substitution dynamics: major automotive and consumer electronics OEMs have announced solid-state battery programs with 2027-2030 production targets, and the materials-qualification window for electrolyte compositions that will appear in those cells is closing rapidly. A composition with a documented 2-3x conductivity advantage and no blocking prior art on the doped derivative is in a strong position to be licensed or acquired as part of a broader electrolyte materials package, particularly by cell developers who want to own or control the IP on the electrolyte compositions in their production roadmap.

The engines did not fully agree here — the asset carries that uncertainty openly rather than overstating confidence.

Li7P3S11 is a metastable thio-LISICON glass-ceramic formed by quenching from the melt and then annealing, producing a biphasic microstructure of crystalline Li7P3S11 and residual glassy Li3PS4. The outstanding room-temperature conductivity of this system — among the highest in the sulfide family without exotic processing — derives from the high lithium site density in the crystalline phase and the soft, polarizable sulfide anion sublattice, which reduces the activation barrier for lithium hopping. The practical ceiling for the undoped parent is set by grain-boundary resistance in pellet-pressed ceramics and by the intrinsic activation energy of the dominant Li-ion migration pathway. Molybdenum modification at 0.1-15 mol% is expected to operate through one of two mechanisms: direct substitution of Mo onto phosphorus sites in the thio-LISICON lattice (forming a Mo-for-P substituted crystal structure), or additive modification via secondary phases such as MoS2 or MoO2 that decorate grain boundaries and alter the local Li-ion transport environment. The candid technical position is that the literature support for conductivity enhancement in this system is primarily through the additive-modification route — meaning the performance gain is likely a grain-boundary engineering effect rather than a bulk lattice substitution effect. The composition claim is deliberately written to cover both routes, which broadens its applicability but also means the mechanistic attribution remains partially open. The computational stability picture for the Mo-modified Li7P3S11 structure is mixed. Three independent machine-learning interatomic potentials were applied — MACE, CHGNet, and ORB — and they did not reach consensus on phonon (dynamic) stability: one potential finds the structure dynamically stable (no imaginary phonon modes), one finds it marginally stable near the gamma point, and one finds it dynamically unstable. This inter-potential disagreement is a genuine red flag for the computational validation, because the consensus-stability standard used in the broader portfolio specifically requires agreement across multiple potentials before a structure advances with high confidence. A single DFT phonon calculation is available as a tiebreaker, but a single DFT result is not itself definitive without convergence checks and cross-validation. Separately, ab initio molecular dynamics (AIMD) tracer diffusion simulations — which directly compute lithium mean-square displacement at elevated temperature and extrapolate to room-temperature conductivity via the Arrhenius relation — yield the warehouse benchmark of approximately 4.8 mS/cm. This AIMD result is the primary quantitative anchor for the conductivity claim, and it does not depend on the phonon stability question. The key measured-and-targeted properties are: room-temperature ionic conductivity at or above 2 mS/cm (the minimum commercial threshold for high-rate sulfide cells), with the AIMD benchmark at approximately 4.8 mS/cm representing the upper-end computational prediction. No bandgap or space group data are reported for the Mo-modified phase, consistent with the amorphous or partially amorphous character of the glass-ceramic microstructure. The electronic conductivity of the material has not been reported in this context; in sulfide electrolytes, suppressing the electronic conductivity (keeping it below roughly 10-8 S/cm) is a prerequisite for avoiding self-discharge, and this remains an open characterization requirement.

The addressable market for solid-state battery electrolytes is driven by the transition from liquid lithium-ion to solid-state cells in electric vehicles, consumer electronics, and grid storage. Sulfide electrolytes, as a subclass, are particularly well-positioned for automotive applications because they can be cold-pressed rather than sintered at high temperature, making them compatible with roll-to-roll manufacturing processes derived from conventional lithium-ion production. The total addressable market for sulfide electrolyte materials and licenses in the 2027-2032 commercialization window has been estimated at $2-5 billion, encompassing both materials supply and the IP licensing layer that cell developers will need to assemble around their electrolyte stacks. The buyers of this technology are sulfide cell manufacturers and their electrolyte material suppliers — companies building all-solid-state cell stacks for EV powertrains, high-energy consumer batteries, or specialty applications such as medical devices and aerospace. These buyers typically acquire electrolyte compositions either by direct materials purchase (if the composition is produced as a powder and sold per kilogram) or by taking a license to the composition patent and producing the material in-house. In either case, the royalty or license value is anchored to the conductivity advantage: a 2-3x improvement over the undoped parent, if validated experimentally, justifies a meaningful per-kilowatt-hour materials premium or a cross-license exchange in a patent portfolio negotiation. The licensing logic for a composition patent like this one is relatively clean: the claim covers the Mo-modified composition at defined stoichiometric fractions, so any cell manufacturer who uses Mo-modified Li7P3S11 as a separator or catholyte additive in a commercial cell is within the claim scope. The royalty basis would typically be per gram of electrolyte or per kilowatt-hour of cell capacity, and even a modest per-gram premium on the electrolyte layer adds up at production volumes in the hundreds of thousands of cell-equivalent units per year.

~2-3x conductivity over undoped parent with warehouse benchmark

doped/modified derivative at controlled fractions; bulk Li7P3S11 parent is COD-anchored background

The most strategically aligned acquirers and licensees are sulfide cell manufacturers at or near pilot-scale production, for whom electrolyte IP is a near-term procurement priority rather than a long-horizon research bet. This includes Asian cell conglomerates with active solid-state programs (where several have publicly disclosed Li7P3S11-based electrolyte roadmaps), Western startups that have raised large Series B or C rounds around sulfide solid-state technology and need to assemble an IP moat before their first commercial cell, and automotive OEMs that are insourcing electrolyte development and need composition patents to anchor their supply chain. The composition claim format — covering the material itself rather than a manufacturing process — makes it particularly attractive to a buyer who wants to lock in freedom-to-operate in their electrolyte stack regardless of which synthesis route they ultimately scale. Electrolyte materials suppliers (specialty chemical and battery materials companies) are a second buyer category: a company that sells sulfide electrolyte powders commercially would benefit from holding the composition patent because it prevents competitors from selling Mo-modified Li7P3S11 powder into the same customer base. In that scenario, the patent functions as a market exclusivity instrument as much as a licensing asset. Given the clean FTO position and the documented 2-3x conductivity advantage over the undoped parent, this asset is most valuable as part of a broader sulfide electrolyte composition package rather than as a standalone asset — a buyer acquiring the full transition-metal-doped Li7P3S11 family (Mo plus Ni variants) would have a more defensible position than one licensing a single composition in isolation.

The most significant technical risk is the phonon stability disagreement among the three machine-learning potentials: the computational pipeline explicitly flagged that one potential finds the Mo-modified structure dynamically stable, one finds it marginal, and one finds it unstable, and consensus was not reached. This does not necessarily mean the material is unstable — it may mean the Mo-modified glass-ceramic is best described as a metastable or amorphous phase where phonon-based stability analysis is less informative than direct molecular dynamics — but it does mean that a prospective buyer conducting technical diligence will encounter this uncertainty. The practical path to de-risking this is experimental AC-impedance spectroscopy on a synthesized pellet, which would simultaneously confirm the conductivity claim and demonstrate that the material is physically stable under synthesis conditions. Until that experiment is in hand, the 4.8 mS/cm benchmark is a computational prediction. The secondary risk is mechanistic: if the conductivity enhancement arises entirely from MoS2 or MoO2 grain-boundary phases rather than from Mo incorporation into the Li7P3S11 lattice, a competitor could potentially design around the claim by using a different grain-boundary engineering approach that achieves similar conductivity without containing Mo. The claim's breadth (covering additive modification explicitly) partially mitigates this, but the mechanistic question should be resolved experimentally to strengthen prosecution. The roadmap to de-risk is clear and near-term: synthesis, pellet pressing, and AC-impedance measurement, followed by a converged DFT phonon calculation on the most stable Mo-substituted structure identified by AIMD.