Decoding Stratus Materials’ technology at the heart of its partnership with Ampère

SOPHIA ANTIPOLIS, France – 28 November, 2025 │ Technical insights and IP analysis of Stratus Materials’ LXMO™ breakthrough battery chemistry.

In a strategic move to advance next-generation battery technologies, Ampère, the electric-vehicle and software-dedicated subsidiary of Renault Group, has entered into a Joint Development Agreement (JDA) with Stratus Materials, a US-based innovator in cobalt-free cathode materials (read more). Under the agreement, Stratus’s proprietary LXMO™ (Lithium Nickel Manganese Oxide) cathode active material will be evaluated in EV-format battery cells at Ampère’s newly inaugurated Battery Cell Innovation Lab in Lardy, France. The collaboration reflects Ampère’s three-phase battery strategy, initially leveraging NMC (nickel-manganese-cobalt) chemistries, then LFP (lithium-iron-phosphate) from 2026, and now advancing toward high-energy, cobalt-free materials aimed at combining high energy density with lower cost, improved safety, and reduced reliance on critical raw-material supply chains.

Stratus Materials: A rapidly scaling startup on high-energy cathode materials

Stratus Materials Inc., headquartered in Pittsburgh, Pennsylvania (United States), was founded in early 2022 (formerly operating as 33 Tech Inc.) and positions itself in the battery value chain as a material manufacturer focused on advanced cathode active materials (CAM) for lithium-ion batteries (www.stratusmaterials.com). The company develops manganese-rich, cobalt-free “LXMO” / LMR cathodes intended for light- and medium-duty electric vehicles (EV) and energy storage applications. As a startup venture-backed pure-play, Stratus Materials has raised approximately US $15–29 million in its seed/Series A funding round, notably with participation from Breakthrough Energy Ventures and DNS Capital. It is currently building a pilot production line targeting approximately 30 tons per year of CAM capacity, and in August 2025 announced that it had begun shipping its second-generation LXMO-2 material to customers and partners. In July 2024, multiple outlets report that LXMO-based pouch cells surpassed 1,000 full depth-of-discharge cycles while retaining >80% of initial capacity, using standard graphite anode and conventional electrolyte (read more).

“In this context, understanding the company’s intellectual property strategy becomes essential to evaluate its positioning and long-term competitiveness. Moreover, a closer look at Stratus Materials’ patent portfolio offers valuable insight into their underlying cobalt-free cathode technology.”, explains Fleur Thissandier, PhD, Senior Technology and Patent Analyst at KnowMade.

Stratus Materials holds a recent but global patent portfolio

Stratus Materials began its patent filings as soon as it was founded in 2022-2023, demonstrating the company’s significant innovation efforts and its intention to secure its technology. To date, Stratus Materials holds six patent families, comprising 31 individual patent applications (none granted yet, with 29 applications still pending). The company pursues a global IP strategy, extending its patent protection across multiple countries, not only in major regions such as the United States, Europe, China, Japan, and Korea, but also in India, Canada, Australia, Brazil, and Taiwan.

Stratus’ patented technology: Doping, Microwave & Ultra-Rapid Quenching

Stratus Materials’ patent portfolio covers several specific high-energy density lithium-rich metal oxide (LRMO) cathode materials, often designed to be cobalt-free. These include layered lithium-rich nickel manganese oxides, represented by the formula Li[Ni_xLi_(1/3−2x/3)Mn_(2/3−x/3)]O₂, where 0<x<0.5 (patent application US20230015455). A subset of these patents focuses on materials characterized by the formula Li_x(Mn_yNi_1−y)_2−xO₂, where x is >1.05 and <1.25, and y ranges from 0.1 to 0.95 (US20250145493, US20230227327, EP4460854). Furthermore, patent applications US20240262709 and US20250145493 introduce substituted lithium-rich metal oxide (S-LRMO) materials, defined by Li[Li_xA_yM_z]O_b, where A comprises Na, K, Ca, or Mg at substitution levels exceeding conventional doping (y>0.05).

Stratus Materials’ patent portfolio focuses on advanced synthetic routes for high-energy density lithium-rich metal oxide (LRMO) cathode materials, specifically addressing the critical issue of structural instability induced by slow cooling. The unifying core methodology across these inventions is the implementation of ultra-rapid quenching (URQ), which involves arresting the material structure by cooling the sintered powder from high temperatures (typically ≥800^∘C) to a low quenching temperature (≤120^∘C or room temperature) in less than 500 milliseconds, achieving cooling rates of at least 1750^∘C/second. This rapid thermal processing is crucial to prevent undesirable changes to the crystal structure, such as oxygen losses and transition metal ion migration, which commonly degrade LRMO performance. Synthesis methods are refined through specialized engineering (US20240353178), such as using a tilted rotary furnace combined with a quick transfer conduit to ensure the powder remains hot (within 200^∘C of the sintering temperature) before hitting the quench fluid (e.g., water, potentially with additives like acids or carbohydrates). Alternative precursor formation techniques enhance homogeneity: precursors may be thermally decomposed using microwave radiation before sintering (US20230227327, EP4460854, US20240262709), which provides efficient volumetric heating, or by aerosolizing a precursor composition at 500^∘C to 900^∘C (US20250145493), a technique that also permits the recycling of gaseous species to improve efficiency and reduce chemical waste.

The patented materials demonstrate superior electrochemical performance and stability. Key advantages include materials exhibiting high specific capacity, such as at least 230 mAh/g after 50 cycles, and S-LRMO materials capable of over 200 mAh/g (C/20 rate). Crucially, the URQ process stabilizes the materials, leading to excellent durability, evidenced by less than 10% capacity fade over 100 C/5 cycles, or even less than 5% capacity fade over 200 C/4 cycles, and low voltage decay (less than 10% loss in average discharge voltage after 100 or 200 cycles). These characteristics indicate that ultra-rapid quenching (URQ) effectively locks in the desired layered hexagonal and monoclinic crystal phases, stabilizing high-energy structures for practical battery applications.

LRMO: A complex but promising rival to LMFP for future Li-ion batteries

Lithium-rich metal oxide (LRMO) cathodes are emerging as a leading next-generation option thanks to their high specific capacities (≈250 mAh.g⁻¹) enabled by combined cationic and anionic redox, offering high energy density at lower material cost. Despite this promise, LRMOs face crucial commercial challenges, specifically low initial Coulombic efficiency (ICE), poor rate capability, and rapid capacity and voltage decay, originating from irreversible structural degradation, lattice oxygen loss, transition metal migration and dissolution, and harmful interfacial side reactions triggered by high charging voltages. In contrast, LMFP, another cathode material envisioned for next generation of Li-ion batteries, is already scaling industrially. LMFP represents an incremental evolution of LFP through the incorporation of manganese to raise operating voltage and boost energy density by roughly 10-20%. LMFP retains the olivine structure, offering excellent thermal stability, long cycle life, and low cost, but its performance remains fundamentally constrained by the polyanionic framework, limiting practical energy density to intermediate levels suitable for mid-range EVs. Thus, LMFP offers near-term, cost-effective performance gains over LFP, while LRMO represents a high potential but technologically more complex long-term pathway for advanced EV batteries.

In this thriving context, KnowMade publishes in-depth reports and provides monitoring services to track and analyze competitors’ R&D and intellectual property strategies. These insights help identify the focus areas of industry leaders, emerging players, and start-ups, offering an early perspective on their strategic direction, technological investments, and product development efforts.

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About the author
Fleur Thissandier, PhD, works as Senior patent and technology analyst at KnowMade in the field of Materials Chemistry and Energy storage. She holds a PhD in Materials Chemistry and Electrochemistry from CEA/INAC, (Grenoble, France). She also holds a Chemistry Engineering Degree from the Superior National School of Chemistry (ENSCM Montpellier, France). Fleur previously worked in battery industry as R&D Engineer.

About KnowMade
KnowMade is a technology intelligence and IP strategy firm specializing in the analysis of patents and scientific publications. We assist innovative companies, investors, and research organizations in understanding the competitive landscape, anticipating technological trends, identifying opportunities and risks, improving their R&D, and shaping effective IP strategies.
KnowMade’s analysts combine their strong technology expertise and in-depth knowledge of patents with powerful analytics tools and methodologies to transform patent and scientific data into actionable insights to support decision-making in R&D, innovation, investment, and intellectual property.
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