The material designed to prevent thermal runaway in batteries enhances safety and could transform the technology industry.
Engineers and materials scientists at LG Chem, the largest chemical company in Korea, have created a material that could significantly lower the risk of thermal runaway and subsequent fires in batteries.
In recent years, there have been numerous reports of battery fires in smartphones and cars, often due to thermal runaway, a condition where the anode and cathode inside a battery become too close or even touch. This causes a short circuit, generating heat and potentially leading to a fire. To combat this, engineers at LG Chem, Korea’s largest chemical company, have developed a thin material that acts as a barrier between the cathode and collector to prevent thermal runaway.
The innovative material works by interrupting the flow of electricity when the battery begins to overheat. Incorporating electronic sensors for this purpose was deemed impractical due to size and vulnerability to heat. Instead, the team designed a thin, conductive material that ceases conductivity at a specific temperature threshold.
This new material, dubbed the Safety Reinforcement Layer (SRL), is a metal composite only one micrometer thick. It was incorporated into a standard battery and subjected to extensive testing. Under normal operating temperatures ranging from 90°C to 130°C, the SRL conducted electricity as usual. However, as temperatures increased, the resistance also rose by 5,000 ohms per degree Celsius, effectively reducing the current. Conversely, when temperatures dropped, the resistance diminished.
Real-world testing included extreme conditions such as driving a nail through the battery or compressing it under a heavy weight—both scenarios typically lead to fires. Remarkably, batteries equipped with the SRL either didn’t catch fire or any small fire that started was quickly suppressed.
The LG Chem team is continuing to test the SRL in various battery sizes and types, aiming to market this technology to battery manufacturers soon.
Reference: In Taek Song et al, Thermal runaway prevention through scalable fabrication of safety reinforced layer in practical Li-ion batteries, Nature Communications (2024). DOI: 10.1038/s41467-024-52766-9
