Real estate is a valuable commodity aboard a CubeSat, a compact satellite about the size of a shoebox, so the smaller each component can be made, the better. To that end, scientists at NASA's Kennedy Space Center and the University of Miami are developing a thin, solid-state battery, which could not only save space for more important instruments aboard satellites, but also provide power on other planets, in cars or within the walls of a home.
At less than 3 mm (0.1 in) thick, the new batteries could be incorporated into the structure of pint-sized satellites, rather than taking up room in the area designated for research instruments. The batteries are made by sandwiching a solid-state battery layer between two layers of compressed carbon fiber.
"Creating a structural battery material could revolutionize the way NASA operates small payloads," says senior principal investigator, Luke Roberson. "Rather than placing a battery in the experiment taking up 20 to 35 percent of the available volume, the battery now resides in the payload structure, thereby opening up additional free space for researchers to perform more science."
The battery begins with a few squares of carbon fiber stacked on top of each other. Then, the stacks are placed in a vacuum bag and "debulked" by sucking all the air out to compress the layers together. These are left for an hour, before being removed from the vacuum bag and placed in an oven set at 250° F (121° C) to cure the resin and bind the fibers together. A prototype of the solid-state battery layer, which will be wrapped in the carbon fiber, is currently being developed at the University of Miami.
The advantages of tucking these batteries into the walls of a device means they could be useful in other applications, too. Building backup batteries into the walls of our homes could help keep power running in the event of a blackout, and they could be designed to resist damage by force, fire and water.
"This technology could be used on satellite structural trusses, the International Space Station, or to power habitat structures established on another planet," says Roberson. "Commercial applications could include automobile frames or tabletop battery rechargers."
After the batteries are put together, the team will investigate ways to reinforce the composition, and mechanically and electrically test the devices.
"We have a great team working on this project, and I hope this technology will become a safe and efficient method to store energy while replacing electrically inert structural components in a wide variety of applications," says Daniel Perez, a researcher on the project from the University of Miami. "We're all working hard for this technology to improve our spaceflight systems and contribute to the advancement of this industry."