The separator isolates the electrodes while allowing lithium ions through; a single pinhole can become the origin of an internal short. DaoAI's high-speed web inline AI-AOI stably detects pinholes and coating defects on fast-running lines.
The separator is the key functional layer in a lithium battery that isolates the electrodes while allowing lithium ions to pass. A pinhole on it directly breaks insulation and becomes the origin of an internal short; coating defects such as scratches, missed coating and thickness non-uniformity affect ion-transport consistency and thermal stability. The battery plant's separator line runs at high speed and wide web width, and the base film is translucent, so defects have low contrast and are often micron-sized. Conventional vision struggles to image stably under high-speed motion and is easily misled by the base-film texture.
The customer needed inline full inspection of pinholes and coating defects without reducing line speed, stabilizing the detection of tiny pinholes to prevent defects from being wound into finished rolls and flowing to the cell process.
DaoAI Solution
DaoAI deployed a high-speed web inline AI-AOI solution: dedicated illumination and high-speed imaging designed for translucent separators make pinholes form a stable contrast signal under transmission or specific lighting, combined with an AI model identifying pinholes, coating scratches, missed coating and thickness non-uniformity. The system uses APDT positive-sample learning to adapt to different film types and coating formulations, with cadence matched to the high-speed line, achieving full-width inline inspection.
- Dedicated illumination and high-speed imaging for translucent separators stably reveal micron-level pinholes
- AI model identifies pinholes, coating scratches, missed coating and thickness non-uniformity
- APDT positive-sample learning adapts to different film types and coating formulations
- Full-width inline full inspection with cadence matched to the high-speed web line
A pinhole is small, yet it can be where a whole cell's short circuit begins.
After go-live, the separator line achieves inline full inspection of pinholes and coating defects at high line speed, with micron-level pinhole detection becoming stable. Defects are located and marked in time at the web stage, preventing them from flowing into the downstream cell process, while consistency and traceability of incoming separator material improve in step.