How to Select the Right Busbar Material for Lithium Battery Packs

Introduction

Choosing the right busbar material is critical for the performance, safety, and longevity of lithium battery packs. The material determines electrical conductivity, heat dissipation, corrosion resistance, and overall cost efficiency.

In this guide, we’ll compare copper, nickel, and aluminum busbars—the three most common materials used in modern EV and ESS systems. You’ll learn how to balance conductivity, weight, and durability to optimize your design.

Check out Wellgo Battery’s custom busbar solutions to find the right fit for your application.

Understand the Function of Busbars in Battery Packs

Busbars serve as the electrical backbone of a lithium battery pack, linking cells together to distribute current safely and efficiently.

A well-designed battery busbar ensures minimal voltage drop and stable power flow, preventing overheating and improving performance consistency.

Reference: U.S. Department of Energy – Battery Pack Design Standards.

Evaluate Conductivity: Copper Leads the Way

When it comes to electrical conductivity, copper outperforms all other materials. With a conductivity of about 59.6 MS/m, copper busbars minimize energy loss, making them ideal for EV high-current systems.

Nickel (≈14.3 MS/m) and aluminum (≈36.9 MS/m) are viable alternatives but less efficient. Designers often use nickel-plated copper busbars to combine copper’s performance with improved corrosion protection.

Table 1: Conductivity Comparison

Reference: IEEE Material Database on Conductivity.

Consider Corrosion Resistance: Nickel’s Advantage

For humid, marine, or outdoor environments, nickel busbars provide excellent corrosion resistance. Nickel forms a stable oxide layer that protects against oxidation and chemical degradation.

This makes nickel busbars ideal for energy storage systems (ESS) exposed to temperature variations and moisture. Alternatively, nickel-coated copper busbars balance performance and protection.

Reference: National Renewable Energy Laboratory (NREL) – Corrosion Study in Energy Systems.

Optimize Cost: Finding a Balance

Material cost plays a significant role in large-scale battery pack manufacturing. Copper offers top performance but comes at a higher price (~$8,400/ton). Nickel costs more (~$18,000/ton), while aluminum is cheaper but less durable.

For manufacturers, Wellgo Battery’s composite copper-nickel busbars provide an optimal cost-performance ratio—reducing total system cost while maintaining efficiency.

Reference: London Metal Exchange – Global Metal Pricing Report.

Factor in Weight and Flexibility

Weight matters in EV battery pack design, where lighter materials improve range and efficiency. Aluminum busbars are about 40% lighter than copper, making them a viable option for weight-sensitive applications.

However, aluminum’s lower conductivity and higher resistance to welding require specialized joining methods, like ultrasonic or friction-stir welding.

Reference: Journal of Power Sources (2023) – “Lightweight Busbar Materials in EV Applications” (Elsevier).

Ensure Thermal Management and Safety

Thermal behavior directly impacts battery pack safety. Copper has the highest thermal conductivity (~401 W/m·K), which helps dissipate heat effectively.

Nickel withstands higher temperatures without deformation, while aluminum offers good heat dissipation at lower cost. Wellgo Battery engineers often combine copper cores with nickel plating to achieve safe, stable heat distribution in compact cells.

Reference: SAE Technical Paper Series – Battery Thermal Interface Materials (2024).

Manufacturing and Joining Considerations

Each material requires specific manufacturing and joining processes:

● Copper busbars are compatible with laser and ultrasonic welding.

● Nickel busbars suit spot welding and high-temperature joining.

● Aluminum busbars need surface treatment to prevent oxidation before bonding.

Wellgo Battery uses precision stamping, CNC machining, and automated welding to ensure dimensional accuracy and strong adhesion in all busbar assemblies.

Reference: ISO 9001 Manufacturing Standards for Battery Components.

Sustainability and Recycling

Sustainability is now a core factor in battery component design. Copper has an 85–90% recycling efficiency, significantly reducing carbon emissions compared to primary extraction. Nickel and aluminum are also recyclable, though with higher processing energy.

Wellgo Battery integrates closed-loop recycling for copper and nickel waste, aligning with global ESG standards for sustainable manufacturing.

Reference: European Battery Alliance – Sustainable Supply Chain Report (2024).

Application-Based Recommendations

Conclusion

Selecting the right busbar material depends on performance goals, cost, and environmental conditions. Copper busbars deliver maximum efficiency, nickel busbars ensure durability, and aluminum busbars offer lightweight flexibility.

For optimal results, hybrid nickel-plated copper busbars—like those designed by Wellgo Battery—combine all three benefits for next-generation EV and ESS systems.

Explore Wellgo Battery’s custom busbar solutions or contact our engineering team to discuss your project requirements.