Cell Defects - Battery Design

There are a number of defects that can occur within a battery cell.

Attia et al [1] categorise these defects as Open-Circuit and Short-Circuit, then list the defects under each.

Open-Circuit Defects

tab weld failure
tab tear
terminal corrosion
premature activation of protection device

Short-Circuit Defects

direct short
- metallic particle contaminants
- metallic burrs and tears from tabs and foils
- missing / insufficient separator overhang
- hole / local weak spot in separator
plating-induced short
- insufficient electrode overhang
- missing / insufficient coating
- overloaded electrode coating
- electrode wrinkle
- electrode buckle
- sharp electrode curvature

Choudhary et al [2] look at autonomous visual detection methods to spot defects in electrode manufacturing.

Exemplary images of defective electrodes captured by Cognex camera placed on the coating machine: a) a coarse accumulation of active material on the electrode surface is referred to as “agglomerate”; b) a hole on the electrode surface is called “bubble” or “pinhole”; c) the active material is coated on the metal foil and the foil is not a part of the electrode; therefore, the left and right side of the electrode is also considered as a defect and labeled as “foil.” The start and end part of the electrode also contains foil; d) a line on the electrode surface is annotated as “scratch.” The lines are created to separate the images and the colors are added to distinguish each defect class, i.e., each category has four images.

References

Attia, P.M., Moch, E. & Herring, P.K. Challenges and opportunities for high-quality battery production at scale. Nat Commun 16, 611 (2025)
Choudhary, N., Clever, H., Ludwigs, R., Rath, M., Gannouni, A., Schmetz, A., Hülsmann, T., Sawodny, J., Fischer, L., Kampker, A., Fleischer, J. and Stein, H.S. (2022), Autonomous Visual Detection of Defects from Battery Electrode Manufacturing. Adv. Intell. Syst., 4: 2200142.