6 materials for electrical and thermal insulation of batteries and accumulators
The importance of electrically powered vehicles is growing: climate protection, fossil fuels that are becoming increasingly scarce and a growing need for mobility due to population growth require new solutions and alternative drives.
Electric vehicles can make a significant contribution to protecting the environment and avoiding emissions. This is why electric vehicles are an integral part of the technology-neutral drive strategies of German manufacturers and suppliers. The leap in battery technology has made electric mobility an option for future mobility.
Developers have focused on utilizing the existing advantages of electric motors over internal combustion engines. This is, for example, the high efficiency of an electric motor.
The lithium-ion batteries used in electric vehicles are constantly being improved. Car manufacturers are developing more powerful lithium-ion batteries that have a longer range and can be charged faster. Along with these improvements, improving safety is becoming more and more urgent in the development of electric vehicles.
Lithium-ion batteries generate a significant amount of heat during operation and charging. In addition to using thermal management materials to dissipate heat, using protective, flame-retardant insulation materials between the battery cell, module, and battery components can provide further thermal and electrical insulation protection.
Materials must be used in the following areas:
- Insulation seals on positive connectors
- cell isolation
- Isolation of serial ports
- BMU isolation
- edge protection
- battery case
- battery insulation
- housing insulation
The following 6 materials are used for the electrical and thermal insulation of batteries and accumulators:
- polypropylene film
- polyester film
- Flame barrier Flame Barrier 3M FRB
- Nomex aramid paper
- polyimide film
- Glimmer
1. Polypropylene film for electrical and thermal insulation of batteries and accumulators
Polypropylene has excellent dielectric properties, excellent impermeability, and is easily deformed. Formex is the first choice for engineers and designers. It is very durable and has excellent dielectric strength. It is also flame retardant (UL94 V-0) and meets strict safety and environmental regulations. PP film can be die cut, scored and folded to create a custom 3D dynamic shape.
2. Polyester films for electrical and thermal insulation of batteries and accumulators
Polyester films (also known by the trade names Mylar and hostaphane) are also used in many applications where electrical insulation, heat resistance and dimensional stability are required. PET films are useful as a dielectric insulator over a relative temperature range. Depending on the application inside the battery, another product may be more suitable for higher temperatures.
3. Flame Barrier FRB inorganic insulating paper for electrical and thermal insulation of batteries and accumulators
3M Flame Barrier FRB inorganic insulation papers are based on inorganic material technology, specially developed for use as a flame barrier in electrical devices. 3M™ FRB Insulation Papers provide excellent resistance to combustibility and ignitability, excellent arc, tracking and dielectric strength, and good thermal conductivity to protect against electrical hazards.
4. Nomex aramid papers for electrical and thermal insulation of batteries and accumulators
Nomex aramid papers have long been used in electrical applications. Nomex, based on meta-aramid fibers, has a wide range of applications. This material is indispensable for manufacturers of motors, transformers or generators. In addition to its dielectric performance, it is characterized by very high thermal resistance (220 °C according to UL 746) and mechanical strength. Properties that are also important in the manufacture of rechargeable batteries and batteries.
5. Polyimide films for electrical and thermal insulation of batteries and accumulators
Polyimide films are commonly used in applications that are subject to extreme heat and vibration. Polyimide films are flame retardant (UL94 V-0) and retain their electrical, chemical and mechanical properties even under extremely harsh conditions.
6. Mica for electrical and thermal insulation of batteries and accumulators
Mica is a mineral material found in the composition of some insulating films. Since it is very crumbly, mica "flakes" can be added to a binder. This mixture is then applied to a substrate to create what we call flexible mica. It can also be added directly during manufacture of a film, as is the case with Nomex® 818. Mica increases dielectric performance and offers thermal barrier properties. This makes it particularly suitable for insulation between cells.
All materials can be punched and self-adhesive.
