– Dr. Dong-yoon Lee’s team at the Korea Electrotechnology Research Institute
– Development of a ‘metal fiber fabric surface heating element’
A technology that can address the weakness of electric vehicles, which suffer from reduced battery performance in winter, has emerged.
Dr. Dong-yoon Lee’s team at the Electric Conversion Material Research Center of the Korea Electrotechnology Research Institute (KERI) has developed a high-efficiency, highly flexible ‘metal fiber fabric surface heating element’ technology to remedy the shortcomings of electric vehicles susceptible to cold.
An often-considered aspect in improving electric vehicle performance is the thermal management system. Internal combustion engine vehicles use waste heat from the engine as a heat source for heating and indoor temperature control. However, electric vehicles lack waste heat, requiring a separate system for heaters, which often leads to decreased driving range.
Inspired by traditional Korean underfloor heating, a leading domestic car group proposed a ‘radiant heat heating system’ that applies a ‘heating element’ to the interior surface area of a vehicle, attracting attention for its energy-saving potential in electric vehicles.
Currently, ‘PTC (Positive Temperature Coefficient) overcurrent protection devices’ are used as heating elements, known for fast heating, self-temperature control to prevent overheating, miniaturization, and low noise advantages. However, their large size, weight, and high power consumption pose significant challenges in electric vehicle applications.
Dr. Lee’s team leveraged previous experience developing fabric-based solar cells and heated clothing technology to propose the ‘metal fiber fabric surface heating element’ technology. This technology begins with a loom that weaves a fabric by interlacing threads horizontally and vertically. The fabric is made using very fine ‘stainless steel micro-wires’ with a thickness below half the diameter of a human hair (50μm), boasting high thermal conductivity and durability. By applying intricate technology, this fabric functions as a heating element, capable of reaching up to 500 degrees Celsius through the internal resistance of the metal when electricity is applied.
The metal fiber fabric features a wide surface form rather than line-based, ensuring even temperature distribution in its heating function, and its excellent flexibility allows it to be easily attached to any curved surface inside a vehicle. It also demonstrates superior efficiency, exhibiting 10-30% higher heating performance than conventional heating wire systems when the same amount of electricity is supplied to the heating element. Moreover, the fabric maintains stable heating performance even amid disconnection or partial damage during use, highlighting its significant strength.
Additionally, this technology holds vast potential as a universal application technology for industries requiring uniform heating, such as in manufacturing (semiconductor production equipment and chemical plant piping, mechanical heating devices), consumer goods (massage chairs, electric blankets, recreational heaters), medical use, and military applications.
Dr. Dong-yoon Lee stated, “Metal fibers are much stiffer than thread, which made weaving extremely challenging, but through collaboration with a textile production and processing company, persistent efforts led to the development of a dedicated metal fiber loom and weaving pattern. This is the world’s first creation of a fabric form heating element using only metal fibers, and it is expected to contribute not only to reducing corporate energy costs but also to achieving national carbon neutrality.”