Technology Licensing Opportunity: Flame-Retardant Electrolytes for Safer Lithium-Ion Batteries

Flame-Retardant Electrolytes for Safer Lithium-Ion Batteries

A non-flammable, high-stability electrolyte system that makes lithium-ion batteries safer and more reliable in extreme environments.

Technology Summary:

A novel class of stabilized phosphoranimines has been developed as air- and water-stable room-temperature ionic liquids (RTILs) with flame-retardant properties and thermal stability beyond 150 °C. These compounds address long-standing limitations of traditional phosphoranimines, which are typically reactive intermediates, by introducing new structural motifs that enable safe handling and practical use. Critically, the materials can solubilize lithium salts and maintain stability in electrochemical environments, making them strong candidates as next-generation electrolytes for lithium-ion batteries.

Supporting research on phosphazene-based electrolytes for lithium batteries provides additional context for this development: https://www.sciencedirect.com/science/article/pii/S001346861631091X

Problem Addressed

Current lithium-ion electrolytes are based on organic carbonates, which are flammable, volatile, and thermally unstable, creating safety and performance limitations in demanding applications. Meanwhile, existing phosphoranimine chemistry has been constrained by unstable intermediates that cannot be readily applied in commercial systems. Industry requires electrolytes that combine flame retardancy, high thermal stability, and tunable performance without sacrificing compatibility with existing battery chemistries.

Solution

The invention introduces a new synthetic route to N-organophosphoranimines using the Staudinger reaction with a stable imidazolium azide precursor. This enables:

• Novel structural features: First demonstration of imidazolium substituents bound to nitrogen (rather than phosphorus), creating unexplored electrochemical behavior.


• RTIL formation with low viscosity: Compound 1 exhibits ~6.5 cSt at 20 °C, while Compound 2 offers higher viscosity, providing flexibility in electrolyte design.


• Air- and water-stability: Unprecedented for phosphoranimines, enabling practical manufacturing and storage.


• Versatile solubility: Distinct solubility profiles across organic solvents (e.g., Compound 1 insoluble in toluene; Compound 2 soluble), aiding purification and application tuning.

Key Advantages

• Flame Retardancy: Inherently non-flammable, addressing critical safety concerns.


• Thermal & Chemical Robustness: Stable at high temperatures and resistant to degradation in air and water.


• Customizable Chemistry: Broad substituent flexibility allows tailoring of viscosity, solubility, and electrochemical properties.


• Electrolyte Compatibility: Capable of dissolving lithium salts and operating within relevant electrochemical environments.


• Novel IP Positioning: Nitrogen-bound imidazolium groups not reported in prior literature, providing strong differentiation.

Market Applications

• Energy Storage: Safer electrolytes for lithium-ion and advanced batteries in consumer, grid, and defense markets.


• Extreme Environments: Aerospace, military, and industrial applications requiring non-flammable, thermally stable electrolytes.


• Chemical Processing: Stable solvents and extractants with tunable properties.


• Industrial Lubricants: Customizable low-volatility liquids with inherent flame-retardant behavior.

Licensing Opportunity:

INL’s Technology Deployment department focuses solely on licensing intellectual property and collaborating with industry partners who can commercialize our innovations.

We do not engage in purchasing, procurement, or hiring external services for technology development. Our objective is to connect with companies interested in licensing and bringing our technologies to market.