German court revokes Zeon patent for battery technology

The Hague, the Netherlands – ARLANXEO reports that the German Federal Patent Court (Bundespatentgericht) has revoked the German part of European patent EP 3 800 714.

This patent, owned by Zeon Corporation, relates to synthetic rubber materials used as cathode binder in rechargeable battery applications, an area of growing importance in electric vehicle and energy storage applications.

The decision follows a patent dispute between Zeon Corporation and ARLANXEO concerning battery binder technology. In 2024, Zeon initiated infringement proceedings at the Munich Regional Court against ARLANXEO entities in Germany and the Netherlands. ARLANXEO subsequently challenged the validity of the patent before the German Federal Patent Court.

In a preliminary opinion issued in July 2025, the Patent Court expressed significant doubts regarding the patent’s validity. Following that assessment, the Munich Regional Court suspended the infringement proceedings pending the outcome of the validity challenge.

With the patent now revoked in Germany, the legal basis for the infringement claims in that jurisdiction has been removed.

“We welcome the Court’s decision, which confirms our position on the invalidity of the patent,” said John Gerrese, General Counsel of ARLANXEO. “The ruling underscores the importance of robust patent standards. It also highlights the critical role of nullity proceedings in ensuring that only valid and enforceable patents are upheld.”