The Power Battery Module is the critical middle layer of Cell → Module → Pack — a single BEV contains 8–12 modules, each with 10–20 cells connected in series/parallel, and the mainstream module copper foil carries 300–1500 A. Two architectural trends, CTP (Cell-to-Pack) and CTC (Cell-to-Chassis), are reshaping the copper foil demand curve: BYD Blade + CATL Qilin follow the CTP route, partially skipping the module layer; Tesla 4680 + BYD Seal follow the CTC route, absorbing the module copper foil into the vehicle body structure. Copper foil plays five major roles in power battery modules: Cell-to-Cell module busbar, module output, module sampling, liquid cooling plate copper layer, and BMS module-level PCBA busbar. Current carrying capacity of 300–1500 A, contact resistance ≤ 0.1 mΩ, flame retardant UL94 V-0, and vibration resistance ≥ 5G — these are the core reasons copper foil is the preferred material for power battery modules. Below, we clarify the specifications of copper foil for power battery modules based on the latest 2025–2026 market data.
I. Four Mainstream Types of Power Batteries
- **BEV (Battery EV, 50–100 kWh)** — Single vehicle 50–100 kWh, 8–12 modules, module copper foil 20–60 kg per vehicle (including Cell-to-Cell + Module Output), emphasizing 800V high voltage, 4C–6C ultra-fast charging, and CTP/CTC trends. Representatives: Tesla Model Y / BYD Han EV / Hyundai IONIQ 5.
- **PHEV (Plug-in Hybrid, 15–30 kWh)** — Single vehicle 15–30 kWh, 3–5 modules, module copper foil 8–20 kg per vehicle, emphasizing dual-power switching, home slow charging, and long range. Representatives: BYD DM-i / Li Auto L7.
- **HEV (Hybrid EV, 1–5 kWh)** — Single vehicle 1–5 kWh, 1–2 modules, module copper foil 3–8 kg per vehicle, emphasizing frequent start-stop, energy recovery, and 10+ year battery life. Representatives: Toyota THS / Honda i-MMD.
- **E-Bus / E-Truck Commercial Vehicles (100–500 kWh)** — Single vehicle 100–500 kWh, 10–20 modules, module copper foil 80–250 kg per vehicle (emphasizing high energy density), emphasizing long cycle life (>5000 cycles), CCS2 fast charging, and 1500V high-voltage architecture. Representatives: BYD K9 / Yutong U12 / Tesla Semi.
Impact on copper foil: BEV + E-Bus emphasize 1.5–3.0 mm thick Cell-to-Cell busbar (high current); PHEV emphasizes 1.0–2.0 mm medium thickness; HEV emphasizes high-frequency cycle life + low cost; the CTP/CTC trend reduces module copper foil usage (jumping directly from Cell to Pack).
II. Three Major Module Architecture Trends
- **CTM (Cell-to-Module)** — The mainstream solution, used by CATL first generation / early BYD, with three layers of Cell → Module → Pack, each module having an independent busbar + BMS.
- **CTP (Cell-to-Pack)** — The next-generation solution, used by BYD Blade + CATL Qilin, skipping the module to reach Pack directly, reducing module busbar by 30–50%, and adopting long cells + large-area cooling.
- **CTC (Cell-to-Chassis)** — The next-next-generation solution, used by Tesla 4680 + BYD Seal, integrating module busbar into the vehicle body structure, reducing module busbar by 50–70%, and integrating the cooling plate into the vehicle chassis floor.
Impact on the copper foil market: CTP/CTC is a double-edged sword — on one hand, it reduces copper foil usage at the module level; on the other hand, it increases large-section busbar + liquid cooling plate copper foil usage at the Pack level. Taken together, the module copper foil market will continue to grow rapidly over the next 5 years (CAGR 5.6–12.5%), and Pack-level busbar + liquid cooling plate are new growth drivers.
III. Five Major Applications of Copper Foil in Power Battery Modules
- **Cell-to-Cell Module Busbar** — Connecting cells in series/parallel, thickness 1.0–3.0 mm × width 10–30 mm, alloy C11000 / T2 copper, nickel or tin plating, current carrying 300–800 A. Mainstream forms: rigid / laminated flexible / braided.
- **Module Output Busbar** — Module → Pack level output, thickness 1.5–3.0 mm × width 20–60 mm, alloy C11000 / T2 copper, nickel or tin plating, current carrying 500–1500 A.
- **Module Sampling Copper Foil** — Module-level voltage + temperature sampling, thickness 0.1–0.3 mm, alloy C11000, nickel plating, with stable signal impedance + anti-interference.
- **Liquid Cooling Plate Copper Layer** — The mainstream cooling solution for power batteries, copper tubes/copper layer inside the cooling plate, thickness 0.5–2.0 mm, alloy C11000 / T2 copper, brazing + nickel plating, thermal conductivity ≥ 380 W/m·K.
- **BMS Module-Level PCBA Busbar** — Internal BMS + inter-module communication, thickness 0.1–0.3 mm, electrolytic copper foil + OSP / ENIG, 1–2 oz copper thickness.
- **CCA (Copper Clad Aluminum)** — A new lightweight solution for modules, 10–20% copper + 80–90% aluminum, weight reduction 30–50%, current carrying capacity decreased 5–15%, suitable for lightweight CTP architecture scenarios.
IV. Key Specifications and Typical Values
| Category | Thickness (mm) | Alloy | Surface Treatment | Typical Application | Key Indicator |
|---|---|---|---|---|---|
| Module Output Busbar | 1.5–3.0 | C11000 / T2 | Nickel / Tin Plating | Module → Pack | Current 500–1500 A |
| Module Sampling Copper Foil | 0.1–0.3 | C11000 | Nickel Plating | Voltage/Temp Sampling | Stable Impedance |
| Liquid Cooling Plate Copper Layer | 0.5–2.0 | C11000 / T2 | Brazing + Nickel | Liquid Cooling | Thermal ≥ 380 W/m·K |
| BMS Module PCBA Busbar | 0.1–0.3 | C11000 (ED) | OSP / ENIG | BMS Internal | 1–2 oz Cu |
| CCA Copper Clad Aluminum | 0.3–1.0 | CCA (10–20% Cu) | — | Lightweight Module | Weight Reduction 30–50% |
Key figures: C11000 ETP (Cu ≥ 99.9%) is the mainstream alloy for module busbar (different from C10100 4N high-end and CCA lightweight); 1.0–3.0 mm is mainstream for module busbar (Cell-to-Cell mainly uses 1.5–2.5 mm); liquid cooling plate copper layer 0.5–2.0 mm is mainstream for new-generation BEV/E-Bus (accounting for 5–8% of Pack weight); CCA copper clad aluminum reduces weight by 30–50%, which is the lightweight solution under the CTP/CTC trend. ASTM B566 (battery copper busbar), UL 2580 (EV battery safety), IEC 62660 (power battery performance), GB 38031 (Chinese power battery safety), GB/T 5231 (wrought copper and copper alloy), and GB/T 3190 (aluminum and aluminum alloy) are the main reference standards.
V. Market Size and Growth
Comparing four independent data sources side by side:
| Data Source | 2024–2025 (USD Billion) | 2030–2035 (USD Billion) | CAGR |
|---|---|---|---|
| Verified Market Research (EV Battery Busbar, Narrow Scope) | 2024 = 1.20 | 2033 = 3.50 | 12.5% |
| Wiseguy Reports (EV Battery Busbar) | 2025 = 1.61 | 2035 = 5.20 | 12.4% |
| QYResearch + Data Insights (Verified Scope) | — | — | — |
Taken together, the global power battery module busbar market in 2024–2025 ranged from USD 1.2 to 5.22 billion (large differences in scope), growing to USD 3.5–8.08 billion by 2030–2035, with a CAGR of 5.62%–12.5% (all four institutions show upward trends). The VMR mainstream scope (EV battery busbar total): USD 5.22 → 8.08 billion (CAGR 5.62%), including module + Pack output + tab; the VMR narrow scope + Wiseguy narrow scope: USD 1.2–1.61 → 3.5–5.20 billion (CAGR 12.4–12.5%), covering only the module level.
Module copper foil demand estimation: 8–12 modules per BEV × 5–15 kg per module = 40–180 kg copper foil per vehicle (including tab, module busbar, Pack output, liquid cooling plate), global 17 million EVs × 30 kg module copper foil average = 510,000 tons per year of module copper foil, corresponding to a market size of USD 0.3–0.6 billion (C11000 average price USD 60–120/kg). The CTP/CTC trend reduces per-vehicle usage by 20–30%, but liquid cooling plate copper foil adds 5–10 kg per vehicle.
VI. Competitive Landscape and Applications
- **CATL (China)**: Qilin Battery / Shenxing Ultra-Charging — the world’s No.1 power battery, 43% market share (2024), with CTP 3.0 Qilin architecture.
- **BYD (China)**: Blade Battery / Flash-Charging Blade — LFP leader, 17% market share (2024), with dual CTP + CTC lines (Seal / 海豹).
- **LG Energy Solution (Korea)**: Korea’s No.1, 11% market share (2024), traditional pouch module architecture (VW / Ford / GM).
- **SK On (Korea)**: Korea’s No.2, 5% market share (2024), pouch + prismatic dual lines.
- **Samsung SDI (Korea)**: Korea’s No.3, 4% market share (2024), prismatic aluminum case + 21700 cylindrical.
- **Panasonic (Japan)**: Tesla’s main supplier, 4% market share (2024), 21700 cylindrical module + 4680 trial production.
- **EVE Energy (China)**: Large cylindrical + energy storage, 3% market share (2024), BMW / Daimler customers.
- **CALB (China)**: Third-tier leader, 3% market share (2024), GAC / XPeng / Changan customers.
VII. Procurement Notes
1. **Identify the copper grade clearly**: C11000 ETP (Cu ≥ 99.9%) is the mainstream for module busbar; T2 copper (GB/T 5231) is the domestic mainstream; CCA copper clad aluminum is used for CTP/CTC lightweight.
2. **Thickness tolerance**: Cell-to-Cell module busbar 1.0–3.0 mm, tolerance ≤ ±0.05 mm; module output 1.5–3.0 mm, tolerance ≤ ±0.05 mm.
3. **Surface treatment**: Nickel plating 3–8 μm is the standard for module busbar (anti-oxidation); tin plating 5–10 μm is for high-current scenarios; brazing + nickel plating is the key for liquid cooling plate.
4. **Current carrying and resistance**: Current carrying 300–800 A (Cell-to-Cell); 500–1500 A (module output); single-point contact resistance ≤ 0.1 mΩ.
5. **Mechanical properties**: Tensile ≥ 200 MPa (C11000-O), yield ≥ 70 MPa, elongation ≥ 35%; vibration resistance ≥ 5G (automotive-grade).
6. **Weldability**: Laser welding + ultrasonic welding + friction stir welding are mainstream; contact area ≥ 80% welding area; shear strength ≥ 30 MPa.
7. **Inspection items**: Thickness tolerance, resistivity (≤ 1.72 × 10⁻⁸ Ω·m), tensile strength, elongation, plating adhesion (≥ 3.4 N), salt spray test (≥ 96h), flame retardant (UL94 V-0), thermal cycling (-40°C ~ 85°C, 500 cycles), RoHS 6 items.
8. **Certifications and compliance**: ASTM B566 (battery copper busbar); UL 2580 (EV battery safety); IEC 62660 (power battery performance); GB 38031 (Chinese power battery); IATF 16949 (automotive quality management); RoHS / REACH (environmental).
Final Thoughts
When selecting copper foil for power battery modules, the key is to remember “five major roles + CTP/CTC trends + liquid cooling plate new growth” — these are the biggest differences from tab copper foil + energy storage module busbar. The global power battery module busbar market will reach USD 3.5–8.08 billion by 2030–2035, with a CAGR of 5.62%–12.5%. CTP/CTC reduces per-vehicle module copper foil usage by 20–30%, but liquid cooling plate copper foil + Pack output busbar are new growth drivers. For copper foil suppliers, each BEV uses 40–180 kg of module copper foil, and the global 17 million EVs sold correspond to 510,000 tons per year of module copper foil demand, a USD 0.3–0.6 billion market, which is an automotive-grade, high-customization, long-cycle B2B track.
If you are evaluating power battery module copper foil suppliers (Cell-to-Cell busbar / module output busbar / sampling copper foil / liquid cooling plate copper layer / BMS busbar / CCA lightweight), please contact Zhengzhou LP Industry Co., Ltd. Email: office@cnlpzz.com, WhatsApp: 0086-19337889070. We offer full-alloy copper foil (C11000 / C10100 / T2 / CCA) + full-process surface treatment (nickel / tin / silver plating / brazing), with Cell-to-Cell busbar current carrying 300–800 A, module output 500–1500 A, liquid cooling plate thermal conductivity ≥ 380 W/m·K, and vibration resistance ≥ 5G. Customized specifications and OEM processing are supported. ASTM B566 / UL 2580 / IEC 62660 / GB 38031 / IATF 16949 compliance support is available.