難燃軽量シート

Flame retardant lightweight composite sheet (Under development)

Recyclable thermoplastic sheet
  • mobility
  • construction

Fire resistance, Flame retardance Weight reduction
Product category Environment

Flame retardant lightweight composite sheet

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.

熱暴走対策、航続距離の向上

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.

不燃性・熱可塑性樹脂シート

Technical information

Technical information

Technical overview

    Flame-retardant, flame-blocking Two characteristics to prevent vehicle fire

Non-flammable

Self-extinguishing,
No ignition and No deformation
防炎 - 不燃性

Non-perforated

Strong resistance to fire blast
Impervious to explosive flame
防炎 - 穴が開かない

 Heat insulation

Surface ≦ 300℃

Vehicle fire prevention
No damage from spontaneous ignition of surrounding parts
軽量

 Light weight

Light weight

Max 61% weight reduction
No insulation and adhesives required
低揮発

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
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
Characteristic 02
Flame-shielding 3-layer sheet

Structure

How it functions
  1. 1.Bottom layer receives LiB ignition ( Flame, active material attack )
  2. 2.Middle layer expands and solidifies
  3. 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

 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 ℃
*Not all vehicle parts would be applied as above.

 Light weight

Solution (stacked structure) comparison

SEKISUI dev.
Hybrid sheet ( All in One )
Thermoforming and recyclable
Glass-mat reinforced thermoplastics

Weight comparison
[1.5m2 estimate]

Document download

  • All
  • Catalog
Name Type File Update File
Catalog:Flame retardant lightweight composite sheet_SekisuiMobilitySolution Catalog pdf 2023-09-11 Download1.06 MB