Tech blanket to keep your EV warm in winter

Posted: February 24, 2025

Cold weather doesn’t just make you shiver. It also damages lithium-ion batteries, which power the majority of EVs. As temperatures drop during winter, the mobility of lithium ions slows down, increasing resistance and reducing overall battery efficiency. The driving range drops, and keeping the cabin warm becomes a costly battle against physics.

According to studies, EVs can lose up to 30% of their range in cold weather when temperatures get down between -7°C and -1°C.

Now, a research team at the Korea Electrotechnology Research Institute (KERI) in Changwon, South Korea, has developed a plane heating element made of metal fiber fabric to maintain EV efficiency and comfort.

How metal fiber fabric technology warms EV batteries 

Conventional vehicles can use the waste heat from the engine to control the interior temperature. But EVs lack sufficient waste heat and require a separate heater to keep both the battery and the cabin warm.

Most EVs rely on Positive Temperature Coefficient (PTC) heaters, a type of thermistor that works quickly but is bulky, heavy and consumes a lot of energy.

As an alternative, the Korean team has brought together their expertise in fabric-based solar cells and heating clothing technologies to develop a metal fiber fabric heating element. The flexible fabric is woven from ultra-thin stainless steel microwires (50μm in diameter). When electricity is passed through the material, it heats up evenly across its entire surface to a temperature of up to 450°C, rather than in concentrated spots like traditional heating wires.

What makes this technology interesting?

• The uniform heat distribution, rather than localized hot spots, provides even warmth across a large surface.
• Flexibility and adaptability make the fabric easily molded to curved surfaces inside the vehicle, allowing seamless integration into seats, floors, dashboards, and even door panels.
• This fabric achieves 10-30% greater heating performance with the same power input as traditional wire heating elements.
• Even if a section of the fabric is damaged, the heating functionality remains intact, making it far more durable than standard wire-based systems.
• Unlike forced-air heating systems, which can dry out the interior, this radiant heating approach offers a more natural and pleasant warmth, similar to the traditional Korean ondol underfloor heating system.

Metal fibers are notoriously difficult to weave and much stiffer than traditional textile threads. The researchers spent years collaborating with Song I Textile Co., Ltd., a specialized textile production company, to develop a customized weaving machine and pattern that could handle metal fibers.

Other applications of metal fiber heating fabric  

While EVs are the most obvious application for this technology, the metal fiber fabric heating element could find applications across multiple industries:

• Manufacturing: Semiconductor production equipment, chemical plant piping, and mechanical heating devices could benefit from its efficiency and uniform heat distribution.
• Consumer products: Think massage chairs, electric blankets, and heated clothing that are not only more efficient but also safer and longer-lasting.
• Medical applications: From heated hospital beds to therapeutic warming devices, this fabric could improve patient care.
• Military and outdoor gear: Soldiers and outdoor workers could have ultra-lightweight, durable heated clothing that functions even in extreme conditions.

In a news release, Lee Dong Yoon, the lead researcher at KERI, said, “This is the first time in the world that a fabric-based heating element has been made solely from metal fibers, and through our achievements, we expect to help companies reduce energy costs and contribute to national carbon neutrality.”