Domestic researchers have developed heating technology to solve the discharge problem of electric vehicles in winter. This technology uses metal like thread to weave fabric and effectively raises the temperature of a large area.
The research team, led by Lee Dong-yun, head of the Electric Conversion Materials Research Center at the Korea Electric Research Institute, noted on the 14th that they developed the 'metal fiber fabric heating element' technology, which increases heating efficiency by up to 30%.
Lithium-ion batteries degrade quickly in cold winter temperatures. When the battery temperature drops, the mobility of lithium ions slows down, leading to increased resistance. Electric vehicles, which primarily use lithium-ion batteries, experience a similar issue. Along with the drop in battery performance in winter, electricity consumption for indoor temperature control increases, significantly reducing driving distance. According to the U.S. Environmental Protection Agency (EPA), energy efficiency of electric vehicles drops by 34% when the temperature is minus 7 degrees Celsius, and driving distance decreases by 57%.
The research team at the Electric Research Institute has found a way to improve the power efficiency of electric vehicles by utilizing thermal management systems. While internal combustion engine vehicles can use engine waste heat to regulate indoor temperatures, electric vehicles generate very little waste heat. The slight waste heat produced by electric vehicles can be harnessed to enhance energy efficiency.
Building on their experience developing fabric-type solar cells and heating medical technology, the research team developed the 'metal fiber fabric heating element' technology. This technology was inspired by traditional fabric manufacturing methods, where threads are woven both horizontally and vertically. They weave fabric using fine stainless steel wires with excellent thermal conductivity and durability, attaching an insulating layer and electrodes to achieve heating effects. When current is applied to the metal fiber fabric, it emits heat of up to 500 degrees.
The metal fiber fabric has excellent heating performance due to its large surface area and is highly flexible, allowing it to be easily attached to curved surfaces inside vehicles. When the same amount of current is applied, it exhibited heating performance up to 30% better than conventional heating wire methods. Additionally, it has the advantage of maintaining heating functionality even in the event of breakage or partial damage.
The research team expects that the newly developed metal fiber fabric can be utilized not only in the electric vehicle industry but also in advanced manufacturing, household goods, medical supplies, and various other sectors.
The head researcher said, "Unlike threads, metal fibers are stiff and difficult to weave into fabric, but we were able to develop a special weaving machine in collaboration with domestic corporations," adding, "This is the first research to create a heating element solely from metal fibers."
The Electric Research Institute has conducted five technology transfers related to the metal fiber fabric technology and is currently preparing to transfer technology to corporations in the electric vehicle and battery sectors.