Propulsion - Energy Storage Technologies

NASA Aeronautics’ vision for aviation research aimed at the next 25 years and beyond has been set forth in the 2014 Strategic Implementation Plan (SIP). It encompasses a broad range of technologies to meet the future needs of the aviation community, the nation, and the world for safe, efficient, flexible, and environmentally sustainable air transportation. The SIP also identifies a set of Strategic Thrusts that represent research areas guiding NASA Aeronautics’ response to global trends affecting aviation.

One of six thrusts identified in the SIP is Thrust 4: Transition to Low-Carbon Propulsion. This thrust seeks to enable the use of low life-cycle carbon alternative fuels for conventional aircraft engines and their future derivatives, and to foster a fundamental shift to innovative aircraft propulsion systems that have the potential to produce very low levels of carbon emissions relative to the energy used.

Electrified propulsion, including turboelectric, hybrid-electric, all-electric, and other variants, is among the promising new technologies that NASA and its partners are developing under this thrust. Future vision aircraft with electrified propulsion range from small aircraft for new mobility missions to small, medium, and large transport aircraft. System studies of several transport-class concepts, such as the Boeing SUGAR Volt, NASA N3X, and Airbus E-Thrust, have shown substantial reductions in both fuel and net energy use. Many of these and other potential new concepts rely on stored energy to provide or augment aircraft propulsive power. In order for some of these concepts to be realized, storage techniques with specific energies on the order of 750-1000 Wh/kg (roughly 4-5 times current state-of-the-art Lithium-Ion batteries), will be needed.

This innovation challenge topic seeks to complement NASA’s current investments in electrified propulsion by focusing on research in high specific-energy storage technologies to address the stringent weight requirements highlighted above for aircraft propulsion applications. Energy storage has indeed been specifically identified as a major risk toward meeting the Thrust 4 outcomes of the SIP.

Examples of energy storage technologies of interest include, but are not limited to, chemical batteries, super capacitors, flywheels, magnetic energy storage, and regenerative fuel cell systems. NASA recognizes that energy storage research requires substantial resources and long lead times; however, the intent in this topic is to leverage the significant investments made by other Government agencies (e.g., DOE, E-ARPA) in energy storage and conduct targeted research that addresses the unique requirements (e.g., weight, altitude, reliability, recharge time, life, safety, and certification) for aircraft applications.