Lithium-ion Battery Tabs

Battery tabs create the pathway through which electrical current enters and leaves the cell. Without them, stored energy cannot be transferred to the device, vehicle or energy storage system being powered.

Beyond conductivity, battery tabs also contribute to thermal management, mechanical stability and pouch sealing performance. A well-designed tab helps improve efficiency while reducing the risk of overheating, leakage and premature cell failure.

The most common battery tab materials are aluminium and nickel-plated copper. Aluminium is typically used on the cathode side of lithium-ion cells, while copper or nickel-plated copper is commonly used on the anode side due to its excellent electrical conductivity.

Advanced battery designs may also utilise bi-metallic tab constructions that combine multiple materials to optimise weight, conductivity and manufacturability.

Aluminium offers an excellent balance of conductivity, weight, corrosion resistance and compatibility with cathode current collectors. It is also significantly lighter than copper, making it particularly attractive for battery applications where weight reduction is important.

Its combination of electrical and mechanical properties has made aluminium the industry standard for positive terminal connections in most lithium-ion battery designs.

Copper provides exceptionally low electrical resistance, making it ideal for handling high current loads found in electric vehicle and energy storage applications. Nickel plating helps improve corrosion resistance and welding performance while protecting the underlying copper.

The result is a robust electrical connection capable of maintaining performance under demanding operating conditions and repeated charge-discharge cycles.

The optimal battery tab depends on the cell chemistry, current requirements, welding process, thermal conditions and pack design. Material selection should balance conductivity, weight, corrosion resistance, sealing compatibility and manufacturing efficiency.

For high-performance applications such as motorsport, aerospace and advanced EV batteries, custom-engineered tab solutions can provide significant performance advantages over standard designs.

Battery tabs are manufactured in a wide range of thicknesses to suit different cell designs and power requirements. Typical thicknesses range from approximately 0.05 mm to 0.80 mm.

Thicker tabs generally support higher current carrying capacity, while thinner configurations can help reduce weight and improve flexibility in compact battery designs.

Battery tab widths can vary from narrow tabs used in small consumer electronics to much wider designs used in EV and energy storage applications.

Selecting the correct width is important because it influences current density, heat generation and weld quality. The ideal geometry is determined by the specific performance requirements of each cell design.

Foil-to-tab welding is the process of joining battery tabs to the electrode current collectors inside a cell. This connection must achieve low electrical resistance while maintaining mechanical strength throughout the battery’s operating life.

The quality of this weld directly influences battery efficiency, heat generation and long-term reliability, making it one of the most critical stages of cell assembly.

Battery tab corrosion can result from moisture ingress, poor sealing, aggressive electrolytes or incompatible material combinations. Over time, corrosion can increase electrical resistance and reduce battery performance.

Using properly engineered materials, stable surface treatments and robust sealing technologies is essential to maintaining long-term cell reliability in demanding operating environments.

Yes. Battery tabs are frequently customised to match the requirements of specific cell formats, chemistries and manufacturing processes.

Customisation can include material selection, dimensions, sealing films, surface treatments and advanced bi-metallic designs. Bespoke tab solutions often improve manufacturability, reduce weight and enhance overall battery performance.

There is no universal “best” material, as the optimal solution depends on the cell design and application.

For many high-current applications, copper-based tabs offer excellent conductivity. However, advanced bi-metallic tab technologies can combine the conductivity benefits of copper with the weight-saving advantages of aluminium, providing a highly attractive solution for electric vehicles, motorsport and aerospace batteries.

Battery tabs are one of the most important safety-critical components in a pouch cell. They must maintain electrical conductivity while also helping contain internal pressure, resist electrolyte attack and support the pouch seal.

Poorly designed tabs can contribute to overheating, leakage and premature cell failure. High-quality tab design improves reliability, enhances thermal management and helps protect the cell during abnormal operating conditions.