How To Choose Flame - Retardant Materials for New Energy Vehicles?

How To Choose Flame - Retardant Materials for New Energy Vehicles?

One of the key trends brought by the rapid development of the automobile industry is lightweight. Nowadays, various modified plastics, composite materials, and light - alloy materials are increasingly used in both traditional fuel - powered and new energy vehicles.

New energy vehicles differ from fuel - powered ones in that they use electricity as the driving force. Thus, electrical safety is crucial. Once a circuit short or high - voltage breakdown happens, parts may stop working. In mild cases, this can cause vehicle breakdowns and leakage; in severe cases, it may lead to vehicle self - ignition. So, in addition to electrical insulation and pressure resistance, the material selection for these electrical - related automotive parts must focus on flame - retardancy.

I. Vehicle Interior

Vehicle interior parts come in a wide variety. They can be generally divided into four categories: textile and leather - based, plastic - based, rubber - based, and composite - material - based. These materials are all flammable or combustible. In case of a vehicle fire, the burning of interior materials can directly harm the occupants. Hence, flame - retardancy of vehicle interiors is of great significance for safety.

Common materials for vehicle interior parts include textile and leather - based, plastic - based, rubber - based, and composite - material - based ones. When it comes to flame - retardancy of vehicle interiors, there's a key parameter we can't overlook: LOI (Limit Oxygen Index), namely the limit oxygen index. The LOI refers to the minimum oxygen concentration required in an oxygen - nitrogen gas flow to maintain steady combustion under specified conditions, expressed as the volume percentage of oxygen.

The limit oxygen index serves as a measure of the relative flammability of plastics and other polymeric materials. It is a very effective way to determine how easily a material will burn when exposed to fire in the air. That's why it's highly valued across the globe. China has also established national standards for the oxygen index method. A high oxygen index means the material is less flammable, while a low index indicates the opposite. Generally, materials with an oxygen index below 22 are considered flammable, those between 22 and 27 are combustible, and those above 27 are flame - retardant.

II. Battery Modules

Currently, there's no unified standard for vehicle voltage worldwide. Different new energy vehicle manufacturers adopt varying voltages. For instance, automotive companies like BYD use new energy vehicles with multiple voltage platforms, including low, medium, and high - voltage ones. The high voltage can reach 690 V, with instantaneous pulses exceeding 800 V. Without flame - retardant materials, voltage breakdown or high - temperature exposure may cause vehicle leakage or self - ignition. Therefore, flame - retardant materials become the first choice for battery module enclosures.

Battery pack enclosures can generally be made of cast steel plates, aluminum alloys, SMC composites (sheet - molding compounds), carbon - fiber - reinforced composites, long - glass - fiber - reinforced flame - retardant polypropylene materials, etc. Plastic enclosures offer good cost advantages and overall performance, making them the primary material for developing power - battery enclosures. As explicit flame - retardancy requirements for power batteries are set, more and more enterprises are using flame - retardant plastics for battery enclosures.

III. Charging Facilities

Charging facilities, including charging piles, high - voltage cables, high - voltage connectors, and charging guns, are as important as in - vehicle power batteries. Their flame - retardancy and safety during charging must be considered. However, standards for charging facilities are not yet fully uniform. Due to varying voltage platforms of different electric vehicles and differences in interfaces and communication protocols, interoperability between charging piles is not achievable, and the problem of vehicle - pile mismatch is very protrude. The charging gun, as the connector for electric vehicle charging, serves as the "bridge" between charging facilities like charging piles and electric vehicles. Its quality directly affects charging performance and safety. The material requirements for charging guns are relatively high. Common materials include PBT + GF, PA + GF, and weather - resistant PC. Materials for sockets and plugs are mainly glass - fiber - reinforced PBT and PA66.

IV. Automotive Connectors

Contact materials for relays, high - voltage connectors, and other electrical connectors are metals with high insertion and removal frequencies. The basic requirement is good flame - retardancy and heat resistance to prevent fires. Common materials for connectors include PBT, PPS, PA, polyphenylene ether (PPE), PET, and liquid crystal polymer (LCP).

V. Automotive Cables

Unlike traditional wires and cables, automotive cables have special application environments, placing high demands on materials. In addition to ensuring insulation, they must also have certain high - temperature resistance, aging resistance, and, when burned, be halogen - free, flame - retardant, and have low smoke density.

Note: XLPE stands for cross - linked polyethylene, TPE for thermoplastic elastomers, TPV for dynamically vulcanized thermoplastic elastomers, TPU for thermoplastic polyurethane elastomers, EPR for ethylene propylene rubber, PVC/HNBR for polyvinyl chloride/hydrogenated nitrile butadiene rubber, and CPE/CR for chlorinated polyethylene/chloroprene rubber.

YINSU Flame Retardant specializes in the research and production of flame-retardant materials and offers a range of flame retardants suitable for automotive applications. For instance, YINSU's T3 is an antimony trioxide replacement, which can effectively replace traditional antimony trioxide in battery module enclosures, providing excellent flame retardancy while reducing environmental impact. There are also red phosphorus flame retardants that can be used for nylon and wire and cable. YINSU also provides other flame retardants tailored for plastics, such as PP flame retardants and ABS brominated antimony masterbatches. PP flame retardants can significantly enhance the flame retardancy of polypropylene materials while maintaining their mechanical properties, making them suitable for automotive interior parts and other plastic components. ABS brominated antimony masterbatches combine brominated flame retardants with antimony trioxide, synergistically improving the flame retardancy of ABS materials, which are widely used in automotive dashboards, instrument panels, and other parts. With its strong technical expertise and diverse product portfolio, YINSU is committed to providing high-quality flame-retardant solutions for the automotive industry, ensuring vehicle safety and reliability.