SBIR-STTR Award

High performance lightweight energy production and storage technologies are needed to supplement or service as the primary power systems for high altitude airships in order to sustain long-term flight schedules. To address MDA~{!/~}s needs, US Nanocorp proposes to demonstrate the feasibility of fabricating a Li-air battery with a special air electrode for lightweight power source application with ensured safety and prolonged service time. Li-air batteries utilizing a non-aqueous electrolyte are capable of delivering extremely high energy, in excess of 3500 Wh/kg based on the mass of the carbon content of the air electrode. However, safety and cycle-life problems limit the application of the Li-air system. The basic causes of safety and cycle-life problems are from moisture attacking on lithium anode and nonaqueous electrolytes. US Nanocorp~{!/~}s solution to these problems is to use an oxygen selective membrane (~{!0~}OSM~{!1~}) permeable to oxygen but impermeable to moisture in air. This OSM will substitute the air diffusion layer as an oxygen accessing element in an air cathode, being totally resistant to moisture diffusion and allow electrolyte and lithium metal anode to be free of attacking from moisture in air. This Li-air battery system can be further developed into both military and civilian applications.

Keywords:
OXYGEN SELECTIVE MEMBRANE (OSM), ELECTRODES, LITHIUM, AIR, BATTERY, CYCLE-LIFE, POLYMER, ELECTROLYTE

The Phase I program demonstrated potential of developing a Li-air battery by using an oxygen selective membrane (OSM) air cathode. The OSM cathode can access oxygen easily while resisting permeability and diffusion of moisture to the electrolyte and the lithium electrode. Successful Phase I efforts have provided the scientific and technological groundwork for further technology advancement in Phase II. In Phase II, US Nanocorp will (1) fabricate scale up production of Li-air battery components; (2) design the structure of the Li-air batteries and construct 150Ah-30 V prototype batteries, and (3) demonstrate prototypes having high energy density of >800Wh/kg and cycle life > 360 with reliable and safe operation. The objectives of Phase II will continue to refine the Phase I demonstrated feasibility, to a point where performance is sufficient to permit an assessment of ultimate application potential to meet MDA’s needs on High Altitude Airship (HAA) application and other commercial applications. Ultralife Batteries, Inc (UBI), the Phase II commercialization partner, will lead in prototype battery fabrication and evaluation. UBI has pledged $150,000 cost share to the Phase II and will carry the follow-on $250,000 investment for full commercialization of this new battery technology, contingent on Phase II milestones being met.

Keywords:
Battery, Li-Air, Osm, Active Carbon, Perflurocarbons, Safety