1. Differences in structural design
Tablesless design: Completely eliminates the traditional independent metal tab structure. By cutting the edge of the current collector (positive aluminum foil/negative copper foil) into a specific shape (such as petal shape), and folding it to form a continuous conductive end face. This end face is directly welded to the current collector, realizing that the entire edge of the current collector simultaneously serves as a current transmission interface.
Omni-tab design: Essentially still a multi-tab structure (such as dozens of small tabs), but it simulates the "omni-tab" effect through dense arrangement. Its current transmission still relies on multiple discrete tab points, rather than a continuous edge interface.
2. Current transmission path
Tables: Current is directly transmitted laterally to the current collector at the edge of the current collector, with a very short path (in the width direction), which can effectively reduce the internal resistance of the battery.
Multi-tab design: The current needs to flow longitudinally along the electrode to multiple tab points, resulting in a longer path and significantly higher resistance than the tabless design.
3. Process and performance advantages
Wuji Ear:
Eliminate welding bottlenecks: Eliminate the tab welding process, avoiding the risk of incomplete soldering. Reduce internal resistance and heat generation: Lower internal resistance results in a 6-fold increase in power and a reduction in charging and discharging temperature rise. Increase energy density: Eliminate the blank area of the tabs and increase the proportion of active material.
All tabs: Multiple tabs still need to be welded, which is a complex process and poses a risk of localized overheating.
Tesla's 4680 cylindrical battery's "tabless" design emphasizes its core innovation of eliminating traditional tabs. The term "multi-tab" is a common industry term for denser multi-tab designs, and it is fundamentally different from Tesla's tabless design.
4. Summary
The tabless design conducts electricity directly through the edge of the current collector, completely eliminating individual tabs; the omni-tab design is essentially a denser variant of the multi-tab design. The former has significant advantages in resistance, thermal management, and energy density, and is one of the core innovations of the 4680 battery.
