SK Nexilis Develops High-Adhesion Carbon-Coated Copper Foil

A panoramic view of SK Nexilis’ Jeongeup plant (provided by SK Nexilis) A new copper foil technology has emerged that can suppress volume expansion and material delamination, chronic problems associated with silicon anode materials. SK Nexilis, SKC’s investment company for its secondary battery copper foil business, said on Oct. 20 that it had succeeded in developing “high-adhesion carbon-coated copper foil” technology that maximizes adhesion with anode materials by coating the copper foil surface with a special carbon material. The technology was developed in line with the battery industry’s trend of increasing the silicon content in anode materials to raise energy density. Silicon anode materials have greater capacity than conventional graphite anode materials, but their volume expands during charging and discharging, making delamination, in which the material separates from the copper foil, more likely to occur. SK Nexilis said it strengthened the bonding force between copper foil and anode materials, enhancing the structural stability of electrodes while improving battery life and safety at the same time. The newly developed copper foil can also be applied to the “dry electrode process,” a next-generation battery manufacturing method. Unlike the conventional wet process, which uses liquid slurry, the dry process has drawn attention as a technology that can dramatically reduce battery manufacturing costs and energy consumption. However, a technology that can stably bond electrode materials to copper foil is essential, and the company expects this new high-adhesion technology to serve as an alternative. SK Nexilis has begun building a pilot production system for full-scale mass production of the technology. It is currently in the stage of verifying process stability and plans to finalize mass production technology later and pursue commercialization in the second half of 2027. An SK Nexilis official said, “This development is an achievement aimed at preemptively responding to the rapid technological changes in the next-generation battery market,” and emphasized that the company would proceed without disruption with optimization work for commercialization to strengthen its technological competitiveness. SK Nexilis is currently carrying out technology verification and production efficiency improvement work centered on its Jeongeup plant.