Jinchuan Group Breaks 3.5μm Ultra-Thin Copper Foil Barrier, Boosting Lithium Battery Energy Density

In September 2025, Jinchuan Group’s Tonggui Co., Ltd. announced a major breakthrough with the successful development of next-generation 3.5μm ultra-thin lithium battery copper foil. The company has overcome long-standing industry challenges such as foil tearing and uneven surface density, marking a significant leap forward in high-performance copper foil technology. This innovation is set to substantially enhance lithium battery energy density, providing fresh momentum for the lightweighting and extended range of electric vehicles.

To tackle the technical bottlenecks of ultra-thin copper foil production, Jinchuan Group established a dedicated task force in April 2025. By systematically streamlining process flows, fine-tuning key parameters, and optimizing additive formulations, the team carried out multiple rounds of pilot and scale-up trials before achieving this technological milestone. Researchers worked closely across laboratories and production lines, while reinforcing equipment monitoring and maintenance to ensure stable and reliable manufacturing.

The new-generation copper foil outperforms current industry standards across all key physical properties. With superior ductility, tensile strength, and uniformity, the product not only extends battery lifespan but also increases energy storage within the same volume. Aligned with the automotive industry’s drive toward lightweight design, it is expected to serve as a critical material enabler for downstream industrial upgrading.

Source：Changjiang Nonferrous Metals Network