Research examines causes of fire risks in EVs

IDTechEx has reported on the materials and strategies being used to reduce fire risks in electric vehicles, with thermal runaway, battery chemistry and regulation identified as key areas of concern.

The research includes data from multiple reports, such as Fire Protection Materials for EV Batteries 2025–2035: Markets, Trends, and Forecasts, and was presented by IDTechEx experts at the Plastics in Electric & Autonomous Vehicles Conference 2025 – SPE Automotive Division.

The company said that various types of failures in EV battery systems, including wiring faults and defects in specific cells, have previously led to vehicle recalls.

According to IDTechEx, these incidents, along with the financial implications for manufacturers, are contributing to demand for more effective fire protection materials.

The organisation stated that thermal runaway can occur not only when driving, but also during charging, in the event of a crash or while the vehicle is parked.

Material technologies being used to mitigate thermal hazards

IDTechEx reported that aerogels are increasingly used to limit heat transfer between battery cells due to their low thermal conductivity and density.

Other materials identified by the organisation as beneficial for thermal protection include foams, ceramics and mica.

Mica, according to IDTechEx, is easier to apply than aerogels or ceramics and can be installed in low-cost sheets that still offer electrical insulation benefits.

The organisation added that while density is higher for mica-based materials, their practicality and affordability make them widely adopted in various battery designs.

Battery chemistries impact EV fire safety

IDTechEx stated that solid-state batteries can improve safety by replacing flammable liquid electrolytes with thermally stable alternatives.

The company explained that this results in better thermal dissipation, fewer hot spots and reduced heat generation in the event of external heating failures.

IDTechEx added that sodium-ion batteries can be stored at 0V, have lower heat release rates than lithium-ion cells and have shown no flames or ignition during nail penetration testing.

The organisation said that lithium-ion batteries using solid-state electrolytes could potentially match the safety of sodium-ion technologies.

Global regulations lag behind safety innovation

IDTechEx reported that while China has a five-minute early warning requirement for thermal runaway events in EVs, this will be increased to a two-hour delay before visible fire or explosion from July 2026.

The company said that no other global regulations currently impose such time-based requirements at the battery pack level.

IDTechEx expects other regions to introduce similar rules eventually, but noted that implementation is likely to be slower and less strict.

It added that some industries, such as aerospace, apply stricter standards for battery safety than those currently seen in the automotive sector.

Fire risks in EVs: battery materials, fire protection and regulatory insights: Summary

IDTechEx has published findings on the use of materials to mitigate fire risks in electric vehicles.

The research identifies thermal runaway as a persistent hazard during driving, charging, collisions and stationary periods.

IDTechEx reported that battery recalls and financial costs have increased focus on improving safety materials.

Aerogels, foams, ceramics and mica are among the thermal protection materials examined in the report.

Mica is noted for its cost-effectiveness and electrical insulation properties.

Solid-state batteries are identified by IDTechEx as offering improved thermal stability.

Sodium-ion batteries can be transported at 0V and may not ignite during penetration incidents.

China requires a five-minute thermal runaway warning and will raise this to two hours in 2026.

IDTechEx states that no other regions currently have similar mandates.

The organisation predicts global regulations will eventually become stricter.