South Korean chemical company LG Chem has published a paper in the scientific journal Nature Communications about the development of a temperature-responsive material capable of suppressing thermal runaway in lithium-ion batteries.

The paper, “Thermal Runaway Prevention through Scalable Fabrication of Safety Reinforced Layer in Practical Li-ion Batteries,” reports on the work of the company’s Platform Technology R&D team, under its CTO division. The team has developed a composite safety-reinforced layer 1 micrometer (1μm) thick that is placed between the cathode layer and the current collector in a battery cell. The layer changes its electrical resistance based on temperature, acting as a “fuse” to block the flow of electricity in the early stages of overheating.

When a battery’s temperature rises to between 90° C and 130° C, the material reacts to the heat, altering its molecular structure. Its electrical resistance increases by 5,000 ohms (Ω) for every 1° C rise in temperature and its maximum resistance is over 1,000 times higher than at normal temperatures. Reversibility means that the resistance decreases and returns to its original state, allowing the current to flow normally again once the temperature drops.

The material was analyzed in collaboration with Professor Lee Minah’s team from the Department of Battery Science at POSTECH, and safety verification was conducted in partnership with LG Energy Solution. In impact and penetration tests, the batteries equipped with the new material either did not catch fire or quickly extinguished the flames, preventing a full-blown thermal runaway event.

“This is a tangible research breakthrough that can be applied to mass production in a short period. We will enhance safety technologies so that customers can use electric vehicles with confidence,” said LG Chem CTO Lee Jong-gu.

Source: LG Chem