Non-flammable zinc flake coating for EV battery cases
When a battery cell goes into thermal runaway, the case has to hold the fire long enough for everyone to get out. GEOMET® 730 EV does not burn. Above 1,500 °C it turns into ceramic.
From Corrosion Protection to EV Battery Safety
GEOMET® 730 EV is a zinc–aluminum–silicon flake coating developed for the upper and lower cases of EV battery systems. It protects the steel against corrosion for the life of the vehicle, and in a thermal runaway it becomes a ceramic barrier between the fire and the passengers. One thin coating replaces a stack of paint and insulation sheets, and it is already in series production.
WE CAN.
Zinc, aluminum and nano-silicon in the coating react under extreme heat and form ceramic phases that melt only at 1,500–1,900 °C. The coating holds instead of burning away. Seven alternative solutions failed the OEM's five-minute torch & grit requirement. GEOMET® 730 EV passed.
How Ceramic Armor worksBattery cases get chipped, scratched and bolted. In damage tests against electro-coating, GEOMET® 730 EV stayed free of red rust in most conditions, because the zinc around a scratch passivates and keeps protecting the steel.
See the corrosion dataLow-temperature curing uses less oven energy and emits less CO₂. No separate conversion coating is needed, and the mica insulation sheet that sits on top of conventional electro-coating can be removed or reduced.
What a simpler stack savesGA steel today, GI steel and aluminum tomorrow. As battery structures change, from aluminum cooling plates that become the upper case to concepts where the body itself covers the cells, one coating follows the design.
Where it goes next| Test | Requirement | GEOMET® 730 EV |
|---|---|---|
| Torch & grit | No ignition, 5 min | Pass |
| Film thickness | ≥ 6 µm | Pass · 13–14 µm |
| Adhesion | Cross-hatch M1.0–M2.5 | Pass |
| Salt spray (SST) | 1,000 h, no red rust | Pass |
| CCT-A | 40 cycles, no red rust | Pass |
| CCT-C | 56 cycles, loss ≤ 10% | Pass |
| CCT-F | 20 cycles, loss ≤ 10% | Pass |
Talk to your regional NOF Metal Coatings team about samples, specifications and licensed coating lines near your plant.
