Self-rechargeable Composite Structures with Carbon Nanoteubs Sueprcapacitors

Advances toward the development of light-weight fully electric aerospace structures leads to the need of replacing on-board batteries with lighter and more efficient energy storage devices and systems. Here a novel self-rechargeable multifunctional carbon fiber composite is presented. The composite has the capability to provide the required energy to the on-board equipment while keeping its structural integrity and strength, increasing its life-time and power capability and decreasing the global weight of the overall aerospace structure. The self-recharging capability is given by a series of miniaturized supercapacitor cells that are first prefabricated on a strategic support already integrated with the necessary circuitry and then are embedded in a cost-effective manner between the layers of the composite. Here it is also demonstrated that supercapacitor cells made with carbon nanotubes electrodes can become lighter and can provide superior performance by thinning its electrodes. For instance, going from 400m to 20m thick electrodes a 1246% power increase, a 21% specific capacitance increase and a 60% electrode resistance reduction were recorded. Moreover the ultra-thin supercapacitors were found to provide these high performance responses with a reaction speed about 30% superior than ever reported in the literature and over an extremely wide frequency range (up to 10KHz). This study is important because it shows for the first time the feasibility along with the great potential of realizing self-rechargeable light-weight structural composites that can work as great energy storage devices and can provide energy during critical flight conditions (e.g. during take-off) and recharge when less energy consumption is required.