Sound Waves Could Make Batteries Better, San Diego Scientists Say
Tuesday, February 18, 2020
A new, thin chip being developed in San Diego could make batteries more useful.
UC San Diego doctoral student An Huang works inside one of the school's many labs. She recently had her arms inside long rubber gloves that give her access to a big box filled with argon gas.
Huang builds batteries here because the thin lithium panels that get stacked inside a battery cannot be exposed to oxygen-rich air.
“It will be changed properties within just like five seconds, so that’s why we need to work in this inert gas,” Huang said.
The batteries contain thin sheets of lithium in a soup of electrolytes. They also have a tiny chip capable of generating high-frequency sound waves.
Those sound waves move liquid electrolytes around the thin lithium sheets.
“This chip is mainly used ... to generate acoustic streaming and this acoustic streaming will help to increase the lithium-ion diffusion rate of a lithium-type of battery technology,” Huang said.
Adding the chip to a lithium battery can boost the amount of energy it holds. It can extend battery life and allow the battery to charge faster. All of those qualities are valuable in a world where batteries are in everything from phones to cars.
“Using a battery like this will quite likely increase the range of a battery-driven vehicle by 100%,” said James Friend, a mechanical and aerospace engineering professor at UC San Diego.
“So, in our analysis, we’ve shown that if you replace a battery in a given electric car, with these types of batteries — including all the extra parts that are required — then for the same weight and size of the battery, you double the range,” Friend said.
He specializes in a field called acoustic-fluidics. That is basically moving fluids with sound waves. Friend said the acoustic chip can work with lithium-ion batteries and possibly alkaline batteries.
The idea could also help make lithium metal batteries stable enough to be used.
“Lithium metal batteries offer roughly two to three times the capacity of lithium-ion batteries,” Friend said. “And so for those cases, where you need very high-performance batteries, they’re the ideal choice.”
The technology is still being developed, but researchers say it could improve all kinds of rechargeable batteries that contain liquid electrolytes.
Longer lasting and more efficient batteries could take some pressure off the environment because they would not have to be thrown away as often.
A private company is exploring marketing the technology.
To view PDF documents, Download Acrobat Reader.