Rechargeable batteries have done a lot to reduce the wasteful and chemically nasty disposal of single-use batteries, but there’s still scope for improving how useful they are—which would further reduce their environmental burden. Which is where, with a sweet irony because carbon by-products tend to be environmental criminals, an unusual type of carbon may change battery tech for the better.
Actually, we may have to think about these products with a different name: Michigan Tech’s scientists have put together a different device, the asymmetric capacitor, that’s half battery, but half not. Unlike most rechargeable batteries that typically use metallic nickel, the Michigan device uses carbon foam—a super cheap and light material—instead. Carbon foam is so light and full of air that 72% of it is just empty space, and this makes it perfect for the battery chemicals to seep inside.
Batteries store electrical charge chemically—as the chemistry inside them reacts, they release heat and the charges, and when the reaction stops… then the battery is flat. Capacitors, like the ones these batteries are made of, store charge electrically rather than chemically. That means that these new carbon foam benefits have many benefits over traditional batteries, including not generating heat as they produce electricity.
Ignore the science here, and read this fact: The team has been testing prototypes and have managed over 127,000 cycles of the battery (charge, discharge and repeat) and they’ve not been able to wear them out yet…which means they hugely overperform against existing battery technology. And for battery-powered heavy machinery, which can require some enormous batteries, the light carbon foam also means the batteries are lighter, which has lots of benefits in their use, in the design of products, and also in terms of transporting thousands of them. Add to that the fact that we can make this carbon foam from biological sources, which means it could be quite a bit more sustainable than mining nickel.
When you add in rechargeable batteries in hybrid or all-electric cars, the benefits of a lighter (and seemingly infinitely rechargeable!) power cells are immediately obvious.