Nanoengineered Multifunctional Structural Power
Abstract
Emerging Navy applications can benefit significantly from systems-level savings of structural power, where the structure and power storage occupy the same mass and volume. Ions, as the working principle for batteries and supercapacitors, are nanometer scale, and therefore nanoengineering can be used to create advantaged structural power solutions, provided the nanoengineering is done at the bulk scale. Indeed, many energy storage advances in recent years have focused on nanoengineered solutions such as aligned or texturedelectrodes for fast ion transport (and high-power density). Here we use facile nanoengineering at the bulk scale to create structural power composites that have the potential to break the current compromising approaches wherein some structural or energy capability is given up when combining the two; rather, we build on recent work that has shown #better-than-one# capability in a structural separator concept, and extend it to better-than-both, i.e., going beyond the limit of 100% system-level benefit via synergistic mechanisms we have identified, that can emerge when combining structural and power functions. We describe a layered composite comprised ofhierarchical fiber composites (structural carbon fibers and carbon nanostructures, CNS) as the structural electrode layers, where the CNS are typically aligned carbon nanofibers (A-CNFs) or carbon nanotubes (A-CNTs), that reinforce the matrix mechanically and at the same time also increase by at least 5000% the active surface area for charge storage; and a structural separator comprised of aligned boron nitride nanotubes (A-BNNTs) that electrically isolates the structural electrodes, but also mechanically reinforces the interface. We introduced the first structural separator comprised of aligned alumina nanotubes (A-ANTs) with demonstrated synergies allowing better-than-one performance via structural reinforcement of the interface, thus increasing structural performance as well asinitiating a more favorable phase of electroactive polymer via polymer morphology modification induced by the hard nanofibers, thusalso increasing energy performance beyond the baseline. A-BNNTs are far advantaged over A-ANTs, and are now a unique capability in the PIs research group. Taken together, the nanoengineered structural separator and composite electrodes have the potential to improve performance into the better-than-both regimes. The #structural polymer electrolyte (SPE) system# comprising the polymer matrix, ionic medium (e.g. ionic liquid (IL)) and ions (e.g. lithium) for the structural electrodes will be further developed based on work over the past year. We have recently identified several promising SPE systems, including sulfonated PEEK (sPEEK) that have the potential to be both structural and ionically conducting in typical aerospace structural environments for composite structures. We will demonstrate structural and power performance of the fully nanoengineered structural power composite supercapacitor device at the cm-scale, and explore additional synergies via polymer matrix morphology tuning. These advances are targeted at structural supercapacitors, but also have application in structural batteries, supporting future Navy and DoD capabilities including extreme system-level performance.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 15, 2024
- Source ID
- N000142412176
Entities
People
- Brian Wardle
Organizations
- Massachusetts Institute of Technology
- Office of Naval Research
- United States Navy