Evrim Yazgin
Cosmos science journalist
Lithium-ion batteries are widely used because they are efficient and long lasting. But they can be disastrous when something goes wrong, and the battery catches fire or explodes.
A new sensor that could solve the problem of overheating lithium-ion batteries is described in a paper published in the journal ACS Applied Materials & Interfaces.
Damaged or overheating battery cells can release volatile electrolyte vapours.
There were at least 20 fires or explosions of lithium-ion batteries in electric vehicles worldwide in 2021, according to the authors. Though electric vehicle battery explosions are a risk, they are rare.
“Lithium-ion batteries are everywhere,” says lead author Liangdan Zhao, a PhD student at Xi’an Jiaotong-Liverpool University (XJTLU), China and the University of Liverpool, UK.
“They power everything from smartphones and laptops to electric vehicles, military applications, and beyond. While they offer high energy density and a long lifespan, they also come with large safety risks.”
“Our research is motivated by this critical safety challenge,” Zhao adds. “By focusing on the early detection of electrolyte leakage, we aim to contribute to safer battery management systems, potentially preventing catastrophic failures and enhancing the overall reliability of lithium-ion battery-powered technologies.”
Ethylene carbonate (EC) is a key component of a battery’s electrolyte. The new sensor detects trace amounts of EC, flagging potential battery failures before they become disasters.
The highly sensitive and cost-effective gas sensor was developed using molecular structures called covalent organic frameworks (COFs). These can be engineered to selectively detect different gas molecules.
It’s the first time a COF sensor design has been guided by computer simulations to detect EC.
“We screened hundreds of potential materials using computational methods before identifying COF-QA-4 as the best candidate,” Zhao says. “It’s highly sensitive and selective, targeting the harmful EC gas while ignoring other vapours. The sensor can detect leaks long before they become hazardous.”
The sensor can detect EC vapour at concentrations as low as 1.15 parts per million in laboratory tests.
“By incorporating this sensor into existing systems, manufacturers can take proactive measures to avoid dangerous situations,” says Zhao. “This could save lives and protect property by detecting potential failures long before they escalate.”
