LG Chem develops material blocking battery thermal runaway

LG Chem Ltd. has developed a material that can prevent thermal runaway in a lithium-ion battery, one of major hurdles to the expansion of the electric vehicle market.

The company announced on Tuesday that its research team joined hands with the research lab led by Professor Lee Minah at the Battery Engineering Department of Pohang University of Science and Technology (POSTECH) to develop a safety-reinforced layer designed to suppress thermal runaway in lithium-ion batteries.

The achievement was published under the title of “Thermal Runaway Prevention through Scalable Fabrication of Safety Reinforced Layer in Practical Li-ion Batteries” in the September issue of Nature Communications, a peer-reviewed, open access, scientific journal published by Nature Portfolio.

LG Chem’s battery unit LG Energy Solution Ltd. also joined to evaluate the material’s safety.

“This is a tangible research achievement that can be applied to mass production in a short period of time,” said Lee Jong-gu, chief technology officer of LG Chem.

“We will enhance safety technology to ensure customers can use electric vehicles with confidence and contribute to strengthening our competitiveness in the battery market.”

The company plans to complete the material’s safety verification test in batteries for mobile devices this year and test its safety in EV batteries throughout next year.

TO EASE CONCERN ABOUT THE EV FIRE RISK

The new development is expected to contribute to easing concern about the fire risk in lithium-ion batteries, often triggered by thermal runaway.  

Battery thermal runaway is the phenomenon of electrochemical chain reactions within a battery, which usually causes excessive heat generation in a short period, leading to battery fire or explosion.  

It is caused by inner or outer mechanical, electrical or thermal shock that leads to the damage of the separator between the anode and the cathode in a battery.

The safety of EV batteries is a hot button across the globe following a series of EV battery fires.

Coupled with the prolonged EV chasm, the growing fears for EV battery fires is making more people shun EVs.

HIGHLY EFFECTIVE IN PREVENTING THERMAL RUNAWAY

LG Chem’s battery thermal runaway suppression material is a composite material in the form of a thin layer, just 1 micrometer thick that is about 1/100th the thickness of a human hair.

It can be placed between the cathode layer and the current collector in the battery, playing the role of an electrical fuse, the Korean chemical giant explained.

When the battery’s temperature rises beyond the normal range, between 90 and 130 degrees Celsius, the newly developed material immediately reacts to the heat, with its maximum electrical resistance shooting up by over 1,000 times compared to that at normal temperatures.

But it is also highly reversible, meaning that the resistance returns to its original state once the temperature drops, allowing the current to flow normally again.

LG Chem said both battery impact and penetration tests showed that the batteries equipped with the new material layer did not catch fire at all or contained the flames shortly after they started, preventing a full-blown thermal runaway.

When it made a puncture on the surface of mobile lithium-cobalt-oxide (LCO) batteries during tests, none of the batteries reinforced with the new material caught fire, whereas more than 80% of the batteries without it suffered from fire.

When the company dropped a 10-kilogram weight on nickel-cobalt-manganese (NCM) EV batteries, all of the standard batteries caught fire, whereas 70% of the batteries with the material stayed stable without fire, according to LG Chem.

The remaining 30% experienced flames but they were put down in a few seconds, the company said. 

Write to Woo-Sub Kim at ter@hankyung.com
Sookyung Seo edited this article.