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 forms Ceramic Armor from 1,200 °C and does not ignite even at 1,500 °C and above.
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 metal 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.
First application at Hyundai Motor Group
The Genesis GV90 is the first Hyundai Motor Group vehicle to protect its battery case with GEOMET® 730 EV. Under the cabin floor, the case is the barrier between the cells and the people.
Battery case
Illustration.
WE CAN.
From about 1,200 °C, the zinc, aluminum and nano-silicon in the coating react and form ceramic phases whose melting points reach 1,500–1,900 °C. Even at 1,500 °C and above, the coating does not ignite. 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. After stone chips, abrasion, cross-cuts and fastening damage, E-coat showed red rust. GEOMET® 730 EV did not, because the zinc around the damage reacts and seals it.
See the damage testsNo conversion coating, no mica sheet on top, low-temperature curing and a thin film. Each removed layer and step saves energy, CO₂ and cost on every part.
Where the savings come fromGA steel today, GI steel and aluminum as well. New platforms move the aluminum cooling plate to the top, where it becomes the upper case. There, a single thin 1C1B coat stops crevice and pitting corrosion in the channels. As battery structures change, one coating follows the design.
See the aluminum story| 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 |
| Impact resistance | DuPont 500 g · 20 cm, no cracking or peeling | Pass |
| Water resistance | 40 °C · 480 h, cross-hatch M1.0–M2.5 | Pass |
| Salt spray (SST) | 1,200 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 |
Requirements include the battery case items planned for the next OEM specification revision.
Beyond anti-corrosion
Saving Lives.
Driving a safer EV era with GEOMET® 730 EV
Talk to your regional NOF Metal Coatings team about samples, specifications and licensed coating lines near your plant.
