A group of scientists at Clemson University has been working on creating smaller, lightweight, fast-charging batteries to use in mission vehicles, spacesuits, and even satellites. Assistant professor Ramakrishna Podila explained: Most satellites mainly get their power from the sun, but the satellites have to be able to store energy for when they are in the Earth’s shadow. We have to make the batteries as light as possible, because the more the satellite weighs, the more its mission costs.
Take, for example, a lithium-ion battery. To be rechargeable, the lithium ions have to be able to move from the negative side to the positive side and back, and they do this through an electrolytic medium between the two electrodes. Picture the negative side as a deck of graphite cards, incredibly thin and stacked together. The problem with using graphite is that it doesn’t store much charge. It’s great for smaller items like cell phones and electric vehicles, not so great for satellites or locations without easy access to regular charging.
The team decided to use silicon instead since it can pack more charge; however, silicon degrades with repeated charging and discharging, breaking down into smaller and smaller particles. Not very good for long-term usage. And that, friends, is where the brilliance of this development comes in.
Per the press release: The solution the team came up with involves the use of tiny silicon “nanosized” particles, which increase stability and provide longer cycle life. Rather than a deck of cards made of graphite, the new batteries use layers of a carbon nanotube material called Buckypaper, with the silicon nanoparticles sandwiched in between.
Now, no matter how much the silicon wants to break down, it’s trapped and electrically connected between those layers of carbon nanotubes. And because the silicon is used as nanoparticles, the battery can be charged more quickly than one using graphite sheets can be.
They managed to make batteries lighter that charge more quickly and have a larger charge capacity. Go, Tigers, indeed.
“Three-Dimensional Si Anodes with Fast Diffusion, High Capacity, High Rate Capability, and Long Cycle Life,” Shailendra Chiluwal et al., 2020 8 July, Applied Materials and Interfaces