A material capable of delaying battery thermal runaway has been developed and is expected to contribute to driver evacuation in the event of future electric vehicle fires.

LG Chem announced on the 27th that it has developed a battery thermal runaway retardant material that withstands a 1,500℃ flame for more than 20 minutes, together with LX Hausys.

The 'special flame-retardant thermoplastic continuous fiber composite material (special flame-retardant CFT)' jointly developed by the two companies is characterized by its ability to withstand strong flames and high pressure for more than 14 times longer than existing composite materials.

According to LG Chem's internal Torch test results, when heat and pressure exceeding 1,500°C were applied to a thin, 1.6mm thick special flame-retardant CFT, it did not melt, run, or develop holes even after 20 minutes. This represents the industry's highest level of flame-blocking performance.

LG Chem's thermal runaway retardant material technology and LX Hausys' Continuous Fiber Thermoplastics (CFT) manufacturing technology were applied to the special flame-retardant CFT. The thermal runaway retardant material developed by LG Chem last year demonstrated the ability to block flames for over 10 minutes at temperatures above 1,000°C, which was the longest duration in the world at the time. LX Hausys improved blocking performance by using a manufacturing process that forms LG Chem's materials into tape form and laminates them.

Special flame-retardant CFTs are rigid and exhibit minimal deformation under force (high rigidity), making them suitable for use in large components of electric vehicle batteries, such as the top and bottom covers of battery packs. In the event of an electric vehicle fire, they are expected to effectively delay the spread of flames, helping to secure the time necessary for driver evacuation and fire suppression.

Thermal runaway, a major cause of electric vehicle battery fires, is a phenomenon in which heat is generated as stress is applied to battery cells due to various causes. Thermal runaway is one of the factors slowing down the popularization of electric vehicles and has been cited as a pain point for EV and battery customers. LG Chem and LX Hausys have resolved the heat and pressure of thermal runaway, which were difficult to withstand with conventional plastics alone, through the development of special flame-retardant CFTs.

LG Chem has been conducting research and development on thermal runaway retardant materials since 2009. Last year, the company completed the development of the material and established a mass production system. Thermal runaway retardant materials, which allow for precise molding, are primarily used in battery modules. As the special flame-retardant CFT developed this year is used in the large battery pack cover that encloses the module, using both materials together can provide a double layer of protection against the spread of flames.

"Since we announced the development of a battery thermal runaway delay material last year, we have been collaborating closely with LX Hausys. We are proud to have a total solution lineup for electric vehicle thermal runaway, including delay materials, glass mats, and CFTs," said Shin Jae-myung, Head of Marketing at LG Chem's Engineering Materials Business Division. "We will continue our research and development to keep the daily lives of electric vehicle drivers safer while addressing customers' pain points."