Istockphoto 487700790 612x612

Flameproofing Coatings for EV Battery Boxes

As we step towards a net-zero future, lightweighting has always been a key practice within the automotive industry.


In the automotive industry in particular, lightweighting has been utilised to reduce vehicle mass and improve fuel efficiency without sacrificing function or safety. Lightweighting is an even more of a crucial factor when it comes to elite motorsport, for obvious reasons. Different lightweight materials such as high-strength steel, magnesium, aluminium and composites are utilised by OEMs in creating their next generation of lightweight vehicles. Incorporating lightweighting techniques into existing designs can provide a range of benefits such as:

  • Materials savings
  • Reduced Environmental Footprint
  • Greater Fuel Efficiency
  • Improved Performance

However, utilising the use of different materials can have an effect on other important factors such as safety.

Lightweight Materials: The Next Generation EVs

As governments across the globe are focused on reaching net-zero, it has led to various development routes in order to boost the adoption of EVs. Lightweight materials are utilised in the development of newer models of Electric Vehicles, enabling them to travel further with no increase of battery size.

One of the challenges arised when it comes to lightweighting in EVs, is the use of carbon-fibre composites for battery boxes. Carbon-fibre composites are arguably one of the most popular choice of materials amongst OEM’s and elite motorsport when it comes to reducing weight and improving efficiency. However, in this particular use of carbon-fibre composites in EVs’ battery boxes, its thermal properties do not make it an ideal choice of material. (Also issues around EMI/RFI, read more on our most recent blog).

Aluminium and steel alloys perform better than carbon-fibre reinforced polymers when it comes to flameproofing, due to the drastic differences in operating temperatures. Depending on the binding resin used, carbon fibre reinforced polymers are typically rated to short term exposure to 150°C, beyond which aesthetics damage, loss of strength occurs. In case of thermal events (thermal propagation and runaway), alone, it provides no fire protection.

Istockphoto 487700790 612x612

Istockphoto 1367402714 612x612

Flameproofing with Zircotec

One of our EV-derived coatings provides flameproofing properties for applications up to 1400°C, preventing structural damage and delamination at high temperatures. This coating has been developed specifically for composite materials such as carbon or glass fibre reinforcement across a range of matrix materials. It’s been tested to withstand 7 minutes of exposure to 1,200°C, roughly the temperature of thermal runaway propagation. In aiding the containment, the thermal activity for this amount of time helps delay the effect from spreading, giving time for driver to remove themselves from the vehicle to safety. On top of thermal protection, our coating can also act as a protective barrier to prevent wear and abrasion.

As advocates of low-carbon and sustainable projects, we continue to champion the adoption of composites within the automotive industry, as using composites will improve efficiencies through lightweighting. Get in touch to find out more about our ThermoHold® For Composites or read more on our EV solutions.