Rechargeable, High Energy Density, Lithium-Air Batteries

Many defense systems such as silent watch, soldier power, unmanned vehicles, communications equipment, and directed energy weapons require portable power which limits the duration and capability of missions relying upon these systems. The DoD is therefore seeking energy storage devices with higher energy densities to extend mission duration and capability. Of all battery technologies currently available, batteries which rely upon lithium-air chemistry have the highest energy density. However, lithium-air battery performance is limited by issues with the metallic lithium anode and poor performance of the cathode. Applied Sciences, Inc. proposes overcome these issues through the use of a carbon nanofiber (CNF) negative electrode coated with amorphous silicon treated to form a stable Solid Electrolyte Interface (SEI), and a positive electrode with a rapid oxygen-exchange catalyst impregnated in a gas-diffusion electrode. The performance and characteristics of negative electrode have already been demonstrated, and this project applies it in the Li-air system. The positive electrode catalyst will be a transition-metal oxide with high activity for O-O bond cleavage and fast oxygen exchange. It is anticipated that the combination of the advanced anode with the proposed cathode will exceed the targeted energy density of 1000 AH/kg, and other performance metrics including cost.