Zhejiang Securities released a recent research report stating that CATL (300750.SZ) has successfully achieved mass production of composite aluminum foil and has already applied it in selected high-nickel ternary battery products. As copper foil represents a major cost component in lithium-ion batteries, battery manufacturers are expected to focus more on its cost-reduction potential compared with aluminum foil products. Against the backdrop of copper prices remaining at historically high levels, this trend may further incentivize battery makers to seek copper-saving solutions.
From a technological perspective, the development path of composite copper foil has gradually converged. Polypropylene (PP) base films and two-step manufacturing processes have largely become industry consensus. After considering yield, efficiency, and cost, the magnetron sputtering plus aqueous electroplating two-step process has emerged as the dominant approach.
CATL Leads Composite Current Collectors
Composite current collectors offer advantages in safety enhancement, higher energy density, and cost reduction. Since CATL disclosed its invention patent “A Current Collector, Electrode Sheet and Battery” in 2017, industry attention toward composite current collectors has steadily increased. Over the years, CATL has secured multiple patents in this field, while companies such as BYD and Gotion High-Tech have also actively expanded their intellectual property布局.
With rising copper prices, battery manufacturers may increasingly pursue copper-reduction solutions. In terms of industrialization, composite aluminum foil has already entered mass production, with CATL applying it in certain high-nickel ternary battery products. For composite copper foil, several industry players have recently disclosed progress in sample delivery. Given copper foil’s significant contribution to battery costs, its cost-reduction potential—especially under elevated copper price conditions—could accelerate downstream adoption once commercialization hurdles are overcome.
Technology Path Narrows: PP Base Film and Two-Step Process
PP has become the mainstream base-film solution. Early industry efforts focused on PET base films; however, PET’s limited chemical stability in electrolytes negatively impacts battery cycle life. As a result, the industry shifted toward PP, which offers superior corrosion resistance, lower cost, and mature processing technologies. Nevertheless, due to its non-polar surface, PP requires surface modification to enhance adhesion with the copper layer.
The two-step process has become the mainstream manufacturing route. Current composite copper foil production methods include magnetron sputtering, vacuum evaporation, electroless plating, and aqueous electroplating, each with distinct advantages and limitations. Considering yield, efficiency, and cost, the magnetron sputtering plus aqueous electroplating route has gained dominance. In this process, a thin copper seed layer (≤100 nm) is first deposited via roll-to-roll magnetron sputtering to ensure strong adhesion, followed by electroplating to thicken the copper layer to approximately 1 μm, benefiting from high deposition rates and lower costs.
Leveraging Shared Technologies, Long Young Electronics Expands into HVLP5 Copper Foil
Driven by AI-related demand, shipments of HVLP copper foil have exceeded expectations. Copper foil is a critical raw material in copper-clad laminates (CCLs) and the upstream PCB supply chain. HVLP copper foil, characterized by ultra-low surface roughness, is specifically designed for high-frequency, high-speed signal transmission and is widely used in AI servers and related applications.
According to Mitsui Mining & Smelting, a global leader in HVLP copper foil, its VSP copper foil sales are expected to reach 580 tons per month in fiscal year 2025, representing a year-on-year increase of 57%, mainly driven by HVLP third-generation and higher products. The company also plans capacity expansion, with total capacity expected to nearly double by 2028, alongside a higher proportion of HVLP fourth-generation and above products.
Leveraging its shared technological foundation, Long Young Electronics is actively expanding into the HVLP5 copper foil segment. The company has deep expertise in electromagnetic shielding materials and has mastered magnetron sputtering and composite coating technologies. It has previously launched composite copper foil products, and its HVLP5 copper foil has already been sampled by several leading CCL manufacturers. Unlike traditional copper foil producers that rely on electrolytic copper foil processes, Long Young Electronics adopts a process combining vacuum magnetron sputtering, precision electroplating, and chemical and physical post-treatment—technologically aligned with composite copper foil production principles.
Source：Sina Finance