Electrolyte for Aluminum-Air Batteries

Aluminum-air batteries produce electricity from the reaction of atmospheric oxygen with aluminum. They have extremely high energy densities, but significant problems remain with byproduct removal due to use of traditional electrolytes. The electrolyte used is an aqueous potassium hydroxide (KOH) solution, incorporated into a polymer-based electrolyte matrix. Traditional alkaline electrolytes enable high ionic conductivity but corrode aluminum, wasting active material and releasing hydrogen gas. Unlike free liquid electrolytes, this hybrid design holds the conductive solution in place, providing the same high ionic conductivity while dramatically reducing the uncontrolled corrosion and gas evolution that typically deplete aluminum electrodes. The polymer host also prevents leakage and drying, improving reliability under demanding conditions such as high altitude and variable temperature environments. The aluminum-air battery electrolyte is a lightweight, high-capacity, and inherently safer primary power source that can meet stringent aerospace requirements for emergency and backup energy. Beyond aircraft, the technology’s combination of high energy density, safety, and sustainable byproducts makes it attractive for electric aircraft, defense systems, and other mission-critical applications. The electrolyte for aluminum-air batteries is available for patent licensing. Aviation electrification requires energy storage that is both lightweight and exceptionally powerful, especially for emergency and backup applications where mission success is dependent on sustained reliability. Conventional batteries struggle to provide the combination of high energy density and intrinsic safety needed for aircraft electrification. NASA’s Subsonic Single Aft Engine (SUSAN) Electrofan program needed an energy-dense solution to these problems. To address this challenge, innovators at NASA’s Glenn Research Center have developed an advanced polymer and polymer-hybrid electrolyte specifically engineered for use in metal-air batteries, with a focus on aluminum-air systems. By embedding a high-conductivity alkaline electrolyte within a solid polymer matrix, this technology overcomes longstanding barriers such as aluminum corrosion, electrolyte leakage, and premature energy loss. This innovation paves the way for compact, high-capacity primary power sources that can support critical aerospace missions and other applications where weight, reliability, and energy security are paramount.