EV Battery Safety: Advanced Coatings, Composite Solutions for Fire and Blast Protection

September 10, 2025

Luc Dusart

Advanced fire- and blast-resistant coatings can accommodate the vertical surfaces and deep troughs associated with EV lids and side panels. (Dow)

Thermal runaway in electric vehicle (EV) batteries is rare, but it can happen, producing smoke, fire, and explosions. This uncontrollable, self-heating state can transfer intense heat to adjacent cells and cause pressure buildups that exceed the mechanical limits of cell casings. Since the gases that can form inside a battery cell are flammable, a spark or other ignition source could propagate fire or lead to an explosion and cause the violent venting of shrapnel or particulates, putting vehicle occupants and emergency responders at risk.

Silicone coatings and flame-retardant polyurethane pultrusion solutions provide high-performance alternatives to traditional materials like mica. (Dow)

To support EV safety, silicone thermal management materials are placed between battery cells and between battery modules. For battery pack enclosures, however, mica sheets traditionally have been used as protective barriers. Mica provides thermal and electrical insulation, but sheets made of this mineral are limited in terms of thermal performance, mechanical durability, processability, and sustainable sourcing. To address these challenges, advanced silicone-based coatings and fiber-reinforced composite systems offer a transformative approach to the safety and manufacturing efficiency of battery enclosures and other EV battery components.

Next-generation, one-part silicone-based coatings that are designed for fire and blast protection resist flames and help contain violent venting by ceramifying at the high temperatures associated with thermal runaway incidents. Unlike traditional mica sheets, these coatings support automated dispensing for high-volume production. Plus, compared to two-part coatings, these new one-part coatings do not require time-consuming mixing. Manufacturers can also precisely dispense a thin layer of this material onto a battery pack surface instead of spraying the coating, which can generate material waste and requires covering or masking of areas that should not be sprayed.

Luc Dusart, global marketing manager of Mobility & Transportation at Dow. (Dow)

Additionally, advanced fire- and blast-resistant coatings can accommodate the vertical surfaces and deep troughs associated with EV lids and side panels. These materials also resist sagging on vertical panels and can fill the recessed areas that are used as cooling channels or to manage and direct the flow of hot gases away from other battery cells in the event of thermal runaway. This helps mitigate both thermal and electrical hazards.

To further enhance safety and reliability for EV battery enclosures, fire- and blast-resistant coatings can be used in conjunction with next-generation, fiber-reinforced composite systems, such as flame-retardant polyurethane pultrusion solutions that provide significant performance, efficient processing, and cost advantages. These composite systems offer structural reinforcement, thermal insulation, and resistance to flame and grit. Their scalable design also supports continuous, high-throughput production across both simple and complex geometries.

Together, silicone coatings and flame-retardant polyurethane pultrusion solutions provide high-performance alternatives to traditional materials like mica and can be tailored to meet specific application needs while aligning with evolving safety standards. As EVs become more mainstream, these two advanced material technologies will be essential for building safer, more efficient, and future-ready battery systems.

Luc Dusart is global marketing manager of Mobility & Transportation at Dow and wrote this article for SAE Media.