Technology Spotlight: Episode 13
Why Dianhydride-cured Epoxy Wire Enamels Matter in Electric Vehicles
Despite customer anxiety, the world is moving towards greener and more efficient personal transportation, with battery electric vehicles (BEVs) at the forefront of this revolution. These vehicles rely on a complex electrical system, where the quality and reliability of copper wiring networks are crucial. An unsung hero of this system is epoxy wire enamel, a special coating that plays a vital role in ensuring that the wiring in BEVs is safe, durable, and functional. The typical BEV requires over 80 kg of copper wire, nearly four times that of a vehicle with an internal combustion engine [1], so let’s break this down in greater detail.
Copper wire is the backbone of the electrical system in any vehicle, including BEVs. It carries the electric current from the batteries to multiple motors and other essential components including braking, telematics, and HVAC systems. However, copper wire on its own is not enough. It needs a protective layer that can withstand the demanding requirements of BEVs. Enter epoxy wire enamels, serving as a tough, protective layer that encapsulates copper wire, shielding it from heat, moisture, and mechanical wear and tear.
Ideally, these epoxy enamels are thermally cured with dianhydrides, creating a coating that is not only durable but also excellent at insulating the wire from adverse service conditions. This insulation is crucial because it prevents short circuits and electrical leaks, ensuring that current flows smoothly without interruption.
One of the key reasons why epoxy wire enamels are so important for BEVs is their inherent thermal stability. Electric vehicles can get very hot, especially in the propulsion and battery areas, where peak temperatures of 200°C are possible [2]. Epoxies thermally cured with dianhydrides can withstand these high temperatures without degradation or loss of protective properties, ensuring that motors remain safe and effective.
Another advantage of using epoxy wire enamels is their excellent chemical resistance. BEVs use various coolant, braking, and hydraulic fluids. Add external/environmental conditions, and the requirements for wiring to withstand exposure and maintain integrity multiplies. This applies to the simplest power window motor to the most complex onboard safety systems.
In summary, epoxy wire enamels, specifically those cured with dianhydrides, are essential for the copper wiring networks found in BEVs. They provide a heat-resistant, chemically stable protective layer that keeps vehicle systems operational. This technology is a humble but crucial part of making BEVs reliable, safe, and efficient, helping to drive the future of clean and sustainable transportation.
Want to learn more about using dianhydrides for epoxy wire enamels, coating powders, encapsulants, and electrical castings? Reach out for an initial consultation today.