South Korean chemical company LG Chem published the paper in a scientific journal Natural Communication about the development of temperature-responsive materials capable of suppressing thermal conductivity 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 group, under its CTO division. The team developed a safety-reinforced composite layer 1 micrometer (1μm) thick that is placed between the cathode layer and the current collector in the battery cell. The layer changes electrical resistance based on temperature, which acts as a “fuse” to prevent the flow of electricity in the early stages of overheating.
When the temperature of the battery rises to between 90° C and 130° C, the material reacts to the heat, changing the structure of the cells. Its electrical resistance increases by 5,000 ohms (Ω) for every 1° C temperature rise and its maximum resistance is more than 1,000 times higher than normal temperatures. Reversal means that the resistance decreases and returns to its original state, allowing current to flow normally again when the temperature drops.
The materials were analyzed in collaboration with Professor Lee Minah's team from the Department of Battery Science at POSTECH, and safety verification was done in collaboration with LG Energy Solution. In impact and penetration testing, batteries equipped with the new equipment did not catch fire or extinguish flames quickly, preventing a full-scale thermal runaway event.
“This is practical research that can be used to produce large numbers of people in a short period of time. We will develop safety technology so that customers can use electric vehicles with confidence,” said LG Chem CTO Lee Jong-gu.
Source: LG Chem