Burn the material for 30 seconds
The material did not catch fire
No ignition and deformation
Surface resin carbonizes and expands
Inner surface remains unchanged
CPVC flame retardant lightweight composite sheet (under development)
Flame-retardant sheet for EVs that achieves both ignition risk suppression and weight reduction
A flame-retardant lightweight sheet developed to address the risks of ignition and fire, as well as the challenge of weight reduction, in lithium-ion batteries for EVs. Its three-layer structure, composed of CPVC and glass mat, provides high strength. Taking advantage of the properties of thermoplastic resin, it is also being considered for use in enclosures of energy storage systems.
- Mobility
- Building / Infrastructure
- Thermal runaway countermeasures, improved cruising range
- Flame-retardant, flame-blocking, heat-insulating thermoplastic resin sheet
- Technical information
- Document download
Thermal runaway countermeasures, improved cruising range
While lithium-ion batteries (LiBs) in electric vehicles (EVs) generate high-output energy, they contain a combustible electrolyte that can cause thermal runaway with malfunction or heavy impact. Currently, steel or aluminum covers which combined with inorganic sheets are used on LiBs to prevent heat and flames from entering the vehicle in the event of a fire, but aluminum adds significant weight, which affects the travel distance of EVs. In order to improve the travel distance of EVs in the future, LiBs must have a higher capacity, reduce weight while maintaining safety.
Flame-retardant, flame-blocking, heat-insulating thermoplastic resin sheet
To address these issues, SEKISUI has developed a thermoplastic sheet with triple performances of fire retardant, flame shielding, thermal insulation. The weight can also be reduced by up to 61% compared to aluminum.
Technical information
Technical overview
Flame-retardant, flame-blocking Two characteristics to prevent vehicle fire
Non-flammable
Self-extinguishing,No ignition and No deformation
Non-perforated
Strong resistance to fire blastImpervious to explosive flame
Heat insulation
Surface ≦ 300℃
Vehicle fire preventionNo damage from spontaneous ignition of surrounding parts
Light weight
Light weight
Max 61% weight reductionNo insulation and adhesives required
Technical details
Flame-retardant,
flame-blocking
Characteristic 01
Non-flammable resin
without flame retardants
Burning test
[Test condition] Apply the flame torch to the developed material for 30 seconds
Surface resin carbonizes and expands Inner surface remains unchangedCharacteristic 02
Flame-shielding 3-layer sheet
Structure
How it functions
- 1．Bottom layer receives LiB ignition ( Flame, active material attack )
- 2．Middle layer expands and solidifies
- 3．Top layer maintains its strength even after contact with flame
Cell runaway test
[Test condition]Verification by placing an actual NMC811/90Ah cell in a casing that imitates a pack, placing a sample between two perforated steel plates, and igniting the LiBs in a thermal runaway.
[Left] Rf. AL
In 2 seconds, the cover was perforated, and the flame penetrated
[Right] SEKISUI Dev. Product
The backside reached 1200°C, but there was no perforation and flame penetration
In 2 seconds, the cover was perforated, and the flame penetrated
[Right] SEKISUI Dev. Product
The backside reached 1200°C, but there was no perforation and flame penetration
Heat shielding
Surface temp. ≦ Spontaneous combustion of interior parts
Fire blast test
Spontaneous combustion of interior parts
| Interior parts | Fire point (°C) |
|---|---|
| Seat (Polyurethane form) |
415 ℃ |
| Floor mat (Polypropylene fiber) |
400~570 ℃ |
| Floor carpet (Polyester fiber) |
490~560 ℃ |
Light weight
Solution (stacked structure) comparison
SEKISUI dev. 
Hybrid sheet ( All in One )
Thermoforming and recyclable
Glass-mat reinforced thermoplastics
Thermoforming and recyclable
Glass-mat reinforced thermoplastics
Weight comparison
[1.5m2 estimate]
Document download
- All
- Mobility
| Name | Type | File | Update | File |
|---|---|---|---|---|
| Catalog 〈Mobility〉：Flame retardant lightweight composite sheet_SekisuiMobilitySolution | Mobility | 2023-09-11 | Download1.06 MB |