Tabless cells spread the electrical connection across more of the electrode edge instead of relying on a small number of tabs. That can reduce a cell-level bottleneck, but the rest of the battery still has to carry the current.
Tabless 21700 Cells
Traditional cylindrical lithium-ion cells use current-collector tabs to connect the internal electrode structure to the cell terminals. Under high current, these relatively concentrated electrical connection points can contribute to resistance and localized heating.
Tabless cells distribute the electrical connection across more of the electrode edge. This reduces the current bottleneck and can improve electrical and thermal performance under high loads.
The primary advantages of tabless construction for an ONYX battery are:
- Lower internal resistance
- Reduced voltage sag under load
- Higher current capability
- Better heat distribution
Tabless architecture became widely known through Tesla’s 4680 cell, but the same general current-collector concept is now available in 21700 cells suitable for high-performance battery packs.
Because ONYX battery packs commonly use the 21700 cylindrical cell format, cells such as the Great Power 60Q, Reliance RS50, Tenpower 50XG, EVE 50PL, and Ampace JP50 can be used when designing compatible 21700 pack architectures.
The cell format alone does not determine compatibility. Pack dimensions, series and parallel configuration, bus bars, cell interconnections, BMS capability, wiring, connectors, insulation, and thermal limits must all support the selected cells and intended current level.
This becomes especially important in applications involving:
- High-current motor controllers
- Field weakening
- Racing configurations
- Aggressive launch tuning
- JAWS MODE
- SICKO MODE
In these applications, reduced internal resistance and voltage sag can help the battery maintain voltage and power more effectively under heavy load while reducing resistive heat generation within the cells.
Tabless Cell Architecture
This design uses only the following tabless cylindrical cells:
- Tenpower 50XG
- EVE 50PL
- Reliance RS50
- Ampace JP50
Tabless cells differ from traditional cylindrical cells in that current is distributed across the full electrode surface rather than a single tab point.
This results in:
- lower internal resistance
- more uniform current distribution
- reduced localized heating
- improved high-current performance
At this level, the cell is no longer the limiting factor.
Tabless design improves cell-level performance, but does not eliminate limitations in interconnects, BMS, or overall pack design.
This shifts the limiting factor away from the cell and into the pack architecture.