New sensor could help prevent lithium-ion battery fires and explosions

Researchers have developed new technology to detect dangerous gas leaks in lithium-ion batteries

With lithium-ion batteries powering everything from smartphones to electric vehicles, safety has become a significant concern. While these batteries are efficient and long-lasting, the results can be catastrophic when something goes wrong.

This issue has become even more pressing with the rise of electric vehicles—in 2021 alone, more than 20 fires or explosions in electric vehicles worldwide were linked to lithium-ion battery failures.

In a study published in ACS Applied Materials & Interfaces, researchers have developed a new sensor that could help prevent these dangerous incidents.

Growing safety risks

“Lithium-ion batteries are everywhere,” says lead author of the study Liangdan Zhao, a Ph.D. 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.”

When battery cells overheat or are damaged, volatile electrolyte vapors can be released and may ignite, triggering fires or explosions. Consequently, there is an urgent need to develop gas sensors that are not only highly sensitive and selective but also low-cost, easily integrated, and energy-efficient.

“Our research is motivated by this critical safety challenge,” explains Zhao. “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.”

Early detection of gas leaks

The new sensor detects trace amounts of ethylene carbonate (EC) vapor—a key component of a battery’s electrolyte—that can flag potential battery failures before they escalate into disasters.

The researchers developed the highly sensitive and cost-effective gas sensor using covalent organic frameworks (COFs), molecular structures that can be engineered to selectively detect specific gases. This is the first time the computationally guided design of a COF-based sensor has been used specifically for EC detection.

“We screened hundreds of potential materials using computational methods before identifying COF-QA-4 as the best candidate,” says Zhao. “It’s highly sensitive and selective, targeting the harmful EC gas while ignoring other vapors. The sensor can detect leaks long before they become hazardous.”

The sensor has shown remarkable performance in laboratory tests, capable of detecting EC vapor at concentrations as low as 1.15 parts per million (ppm).

Enhancing safety across industries

The researchers say the sensor’s potential impact extends far beyond electric vehicles. It could also be integrated into battery management systems across smart home devices and industrial safety systems, providing real-time alerts for hazardous gas leaks and offering an early warning system that could prevent catastrophic accidents.

“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.”

The research was supervised by Dr. Lifeng Ding and Dr. Qiuchen Dong, both from XJTLU.