SBIR Phase I:Structural Multifunctional Composites with Energy Storage Properties

This Small Business Innovation Research (SBIR) Phase I project will develop a nanostructured, lightweight material which, in addition to its high mechanical strength, can also be used to store electrical energy. Such materials can be produced in the form of large formable sheets, cylinders, or other three-dimensional shapes. A unique production process is used, based on a high speed layer-by-layer formation of nanometer-thick metal layers separated by nanometer-thick polymer layers, resulting in a structure with tens of thousands of layers. The nanometer separation of the metal layers prevents the propagation of dislocations, which results in metal/polymer nanolaminate composites with superior mechanical properties. Preliminary work has shown that aluminum/polymer nanolaminates have lower density and higher tensile strength than aluminum sheets of equal thickness. The same metal/polymer structure has previously been used to produce electrostatic capacitors, where the aluminum metal forms the capacitor electrodes and the polymer layers form the capacitor dielectric. Nanolaminate capacitors used in electronic applications can operate over a wide temperature range, have very high volumetric efficiency and are self-healing. The major objective of the proposed development is to combine the structural and capacitive storage properties into one material system. The broader impact/commercial potential of this project lies in applications that combine a need for lightweight structural materials with a need for energy storage. High-strength, lightweight polymer-metal multilayer nanocomposites with electrical energy storage properties could replace supercapacitors and structural components in hybrid and electric vehicles, commercial and military aircraft, various battery operated platforms, and mobile pulse power applications. Conventional electrochemical supercapacitors are battery-like devices that can be used to backup batteries due to their ability to undergo a large number of charge/discharge cycles with minimum degradation. Like batteries, they are subject to temperature limitations, require being located in a specific location within a vehicle, and can fail catastrophically (short-circuit). The structural nanolaminate storage devices to be developed can handle temperatures higher than most thermoplastic materials, are durable enough to be integrated into exterior or interior panels of a vehicle, have an open-circuit failure mode and are composed of low-cost materials. Such multifunctional structures are expected to play a major role in improving energy efficiency and reducing dependency on fossil fuels.