Meaning
Structural connection breakages represent the primary electrical discontinuity that occurs at the junction of the cell tab and the busbar. The cell tab interconnect failure leads to a complete loss of current flow or a sudden voltage drop in the battery module. Procurement agents track these defects to evaluate the performance of pack assembly lines.
Defect Origin
Laser weld voids or ultrasonic weld fatigue typically initiate the joint separation. During cycling, the cell tab interconnect failure develops when thermal expansion stresses exceed the tensile strength of the welded zone. Vibration on the road accelerates this mechanical degradation, causing high electrical resistance.
Procurement Action
Supplier quality standards require extensive thermal shock testing to screen out weak interconnect designs before pack assembly. When comparing modules from different vendors, the cell tab interconnect failure rate indicates the reliability of the manufacturing process. High failures during testing require a change in welding parameters or joint geometry, prompting a revision of the supplier contract.
Boundary Exception
High current spikes can melt thin weld joints even without mechanical vibration. Under extreme discharge rates, the cell tab interconnect failure happens due to thermal runaway rather than weld fatigue, shifting the problem from assembly quality to cell design.
