Solus Advanced Materials won a European battery foil patent infringement lawsuit against SK Nexilis. Solus Advanced Materials said on Oct. 26 that the Mannheim local division of the Unified Patent Court (UPC) dismissed SK Nexilis' claim. Battery foil is copper foil used for the anode of secondary batteries. The court ordered SK Nexilis to pay 1.1 million euros, about 1.65 billion won, to Solus Advanced Materials for litigation costs.

SK Nexilis filed the lawsuit in 2025 against Volta Energy Solutions, Solus Advanced Materials' European unit. The patent corresponds to 1 of 5 patents in a lawsuit SK Nexilis filed in 2023 in a Texas court in the United States. The dispute over the same technology expanded from the United States to Europe.

The issue was the measurement standard for the surface roughness indicator, Rpc (Peak Count Roughness), stated in the patent claims. The patent stipulates that there must be 10 to 100 effective peaks that actually exist within a 4 mm sampling length. SK Nexilis cited the calculation methods of some measurement equipment and industry practice. It argued that Rpc should be calculated by converting the number of strong peaks in a 4 mm section to a 1 cm basis.

The court did not accept the conversion method. It said it departed from the wording of the claims and the specified measurement standard. When the court strictly applied the claim standard, the Rpc value of Solus Advanced Materials' products fell short of the minimum 10 required by the claims. The court found the products were not within the technical scope of the patent and dismissed the infringement claim.

A Solus Advanced Materials official said, "We respect the court's decision and positively assess that we received a ruling of non-infringement in this European lawsuit." The official added, "We will continue stable business activities in the European market and faithfully respond to related lawsuits that are under way."