Although electric vehicles are becoming more common worldwide, battery safety is still a major concern for many car users. According to the latest Asahi Kasei Automotive Consumer Survey, 34 per cent of non-EV owners in China see improved safety as a primary consideration in buying an electric vehicle. Against this background, global OEMs seek to further raise the safety of EV batteries, and the market for materials to prevent thermal runaway is expected to grow by some 15 per cent annually from 2024 onward, with even further expansion of demand in the future (IDTechEX: Fire Protection Materials for Electric Vehicle Batteries 2024–2034).
Japanese company Asahi Kasei has announced the launch of Lastan, a flame-retardant, flexible nonwoven fabric designed to enhance EV battery safety by preventing thermal runaway.
With high flame resistance, electrical insulation up to 3.5 kV, and excellent processability, Lastan is a superior alternative to conventional mineral-based materials.
In this context, there is increasing demand for materials in EV battery cover applications having excellent resistance against flames and particle blasts, as well as good electrical insulation properties. While mineral-based materials are generally used as protection against thermal runaway at present, such materials tend to be heavy and brittle. Being stiff, these materials are difficult to adapt to complex shapes, making processability an issue for automotive OEMs, the company said in a press release.
Lastan is a non-mineral flame-resistant fabric made by air baking a special acrylic fibre at 200–300?. It is characterised by high flame resistance and good electrical insulation, which are further improved by a special coating process that also augments abrasion resistance. This allows the material to provide effective protection against particle bombardment from venting gas. With these exceptional characteristics, Lastan has been used for many years as an optimal material for failure prevention and safety in various industries.
Even when a 1,300? flame is applied, the temperature on the opposite side of Lastan remains below 400?. While a limiting oxygen index (LOI) value of 27 or higher is generally considered to indicate flame retardance, this material has an LOI value of 50 or higher. In UL94 flame retardance testing, Lastan has obtained the highest rating of 5VA. No holes are formed in Lastan even when it is exposed to a flame of 1,300? for one minute.
In addition to its high flame resistance, Lastan is resistant to high-pressure impact by particles of 200–500 µm. It also provides electrical insulating capacity of up to 3.5 kV at a thickness of 1 mm. Lastan also features outstanding processability, being highly flexible while maintaining its performance characteristics in sheets as thin as 0.8 mm. This makes it easily processed with ordinary tools, contributing to a simplified manufacturing process.
Having integrated production of Lastan currently in Japan, Asahi Kasei is considering production in the United States and other countries in the future. The company will exhibit the new Lastan grade at the North American Battery Show from October 7-10, 2024, in Detroit, Michigan.
Fibre2Fashion News Desk (RR)
