New thermal battery chemistry and construction for Interceptors

Based on recently-developed InvenTek intellectual property, an opportunity exists to facilitate a revolutionary increase in power and energy for reserve battery with molten nitrate electrolyte that can be operated as a thermal battery. Simply put, there is an opportunity for advanced thermal batteries that are an analog of Li-ion batteries with the substitution of molten nitrate salt electrolyte. The technology provides many options for reserve battery design and operation. The nitrate molten salt brings much reduced thermal input to initiate at lower temperature of 160-200oC with the low thermal mass Li-ion configuration. The proposed SBIR initially taps aspects of conventional Li-ion battery chemistry and manufacture with some new materials. InvenTek will push the boundaries of voltage, temperature, and compositions of adapting conventional Li-ion to nitrate molten salt electrolyte cell operation. For meeting ultimate MDA performance goals, a new high voltage (4.5V), high capacity (200mAh/g) Li-ion cell chemistry (Prof. Jai Prakash) is coupled with the very thin components typical of Li-ion batteries. The revolutionary battery performance relies on Li-ion chemistry and configuration. Selected prospects are adapted to the nitrate salt electrolyte to give it thermal battery functionality of long-term, inert stand. Not with standing the reserve mode of thermal battery application, Inventek will demonstrate a robust design to enable temporary (hours duration) secondary battery operation for periodic testing and reuse (recharge) of the nitrate electrolyte thermal. Both specific energy and power can be doubled over conventional thermal batteries with high power/energy Li-ion chemistry and reduced cell mass via very thick separator (20-25 micron). The combination of very thin and nitrate electrolyte/metal oxide electrode (4.5V) can approach 200Wh/kg and 10kW/kg in battery configurations typical of Li-ion. Robust design and manufacturability make this approach viable for commercial applications (always important for cost-effective production). Phase I will provide a proof of concept demonstration of the nitrate cell technology and provide a basis to project the revolutionary thermal battery performance required for the Ballistic Missile Defense System (BMDS) interceptors. In Phase II, Inventek will collaborate with prime contractors (and component providers) to narrow options in design, and pursue qualification of a thermal battery configured for a targeted MDA SM3 application. Innovation of thermal battery cells using Li-ion with molten nitrate electrolyte can improve performance reliability and lower cost for missile defense systems, such as SM3IIB. The addition of conventional battery design for thermal battery aids in design flexibility to shorten time to production. With a basis for volume & packaging efficiency and high current capability, a Li-ion analog has the ability to achieve high voltage levels (>200 volts), safety and reliability for the intended use in interceptor vehicles.