Cylindrical lithium-ion cells have long used metal tabs to connect the current collectors to the terminals. These tabs act as the path for current to flow out of the electrode layers and into the external circuit. While this design has been reliable for decades, it introduces a few well-known limitations, particularly for high power applications.
Tabbed Design
In a tabbed cell, current is forced through relatively narrow contact points. This leads to higher internal resistance, uneven current distribution, and greater I²R heating during high current operation. It can also create localised thermal hotspots, which may limit performance or complicate thermal management.
Tabless Design
Tabless designs, by contrast, connect the entire edge of the electrode to the terminal. This spreads current flow evenly across the surface, reducing resistance and lowering heat generation during operation. A tabless structure also removes the space and mass taken up by the tabs themselves, enabling higher energy density by allowing more active material to be packed into the cell.
Tesla highlighted the benefits of tabless architecture during their Battery Day presentation in 2020, showcasing it as a key enabler for better performance and manufacturability in large-format cells (Tesla 4680 Cell) .
However, tabless designs are not without trade-offs. They can introduce new challenges in manufacturing, such as ensuring consistent weld quality or managing electrode alignment at scale. These factors have historically limited adoption, especially in mass production.
That is beginning to change. More cells are now being released with tabless designs, such as the EVE 50PL. With improved power handling and higher energy density, cells like these are becoming increasingly competitive for high performance applications across EV, motorsport, and aerospace sectors.
For engineers working on next-generation battery systems, understanding these design differences is key to making informed cell selection choices.
Pros and Cons of Tabless Design
Tabless Design – Pros
- Lower internal resistance – current flows more evenly across the electrode
- Reduced heat generation – less I²R loss, better thermal performance under load
- Higher energy density – more room for active material due to removal of tabs
- Improved power capability – better suited for high current applications
- Potentially simpler thermal management – due to fewer hotspots
Tabless Design – Cons
- More complex manufacturing – precision welding and alignment are critical
- Higher initial production cost – new equipment or processes may be required
Still emerging in mass production – fewer cell suppliers currently offer it at scale
About:Energy
A data company that offers software to enhance battery performance throughout its lifetime. Its platform, “The Voltt”, reduces time and costs in developing new electric products for various industries. Utilizing advanced battery testing methods, this platform facilitates cell selection, benchmarking, and system design. Catering to anyone aiming to improve battery performance metrics, it efficiently trims down cell selection times from months to minutes through its comprehensive cell library. Users can leverage this resource to benchmark their emerging cell chemistries, maintaining a competitive edge by evaluating rival performance. Providing cloud-based tools and downloadable models, “The Voltt” aids in optimizing system designs by offering insights into battery pack behaviour