Battery pouch cells have a soft enclosure, which is delicate and susceptible to damage. Once manufactured, battery cells are placed into battery modules or packs and can’t be removed for inspection. So this application focuses on final inspection of battery pouch cells before integration into a module or pack.
What manufacturing defects occur?
Pouch cells have a soft enclosure, which is delicate and susceptible to damage. Throughout the cell assembly and finishing processes, pouch cells sustain defects such as:
These defects can impact the quality, safety, and performance of pouch battery cells and cause costly recalls and legal liability, making it crucial for manufacturers to implement rigorous quality control measures and inspection processes to detect and rectify these issues during production.
Additionally, manufacturers need to distinguish between acceptable cosmetic blemishes and functional flaws in order to avoid overkilling battery cells and ultimately reduce scrap rate.
However, pouch cell defects are difficult to detect. Direct illumination can wash out the defect, making it hard for inspection systems to image the part. They also are made up of multiple materials, each requiring a different lighting configuration for ideal imaging.
And in high-volume manufacturing environments, cells must be inspected quickly to keep up with production rates. Traditional machine vision products may fail to keep up with required cycle times.
The Solution
UnitX’s AI-powered inspection effectively detects pouch cell defects where other solutions fail.
First, the OptiX imaging system illuminates and images assembled pouch cells. Then, the CorteX Central AI platform is trained on pouch cell defects. Lastly, those AI models are deployed to the CorteX Edge inference system to detect and classify defects in-line.
Why UnitX for final pouch cell inspection?
OptiX provides superior imaging of varying pouch cell materials. It has 32 independently controllable lighting sources that can be optimized for pouch cell surfaces and defects via software. And its lighting dome design supports a very acute incidence angle of projected light, causing even very tiny defects to cast shadows which increase their visibility.
CorteX accurately detects random, complex defects. It automatically normalizes for variability in positions and orientations and recognizes defects down to the pixel-level.
UnitX supports fast experimentation and adapts to changes in production environments. OptiX lighting is easily configured via software and CorteX AI models are sample efficient– they only require a few images to train on new defect types.
UnitX provides rapid, 100% inline inspection. OptiX has bright LEDs and fast fly capture speeds of 1m/s for high speed imaging. And CorteX Edge supports high inference speeds (up to 100 MP) to quickly output an OK/NG decision, seamlessly communicating that decision via integration to all major PLC, MES, and FTP systems
With UnitX, manufacturers automate pouch cell final inspection to:
- Prevent quality escapes that cause degraded battery performance and failure, safety risks, and costly recalls
- Minimize false rejection rates common with traditional machine vision, reducing scrap and wasted materials
- Replace manual inspectors, saving manufacturers money and improving efficiency
UnitX Inspection Example Deep Dive
In this example, we inspected battery pouch cells for scratches, dents, porosity, and contamination.
Imaging
First, we used OptiX to capture images of the pouch cells, making sure we captured both defective and OK parts.
Training
Next, we used CorteX Central to train our models. We created a label for the 4 defects we want to detect: scratches, dents, porosity, and contamination.
We then labeled those defects in the images we captured from OptiX, using just a few images of each defect type.
Detection
Next, we deployed the AI models to CorteX Edge on new cells, resulting in the accurate detection and classification of pouch cell defects.
Example of pouch cell scratches detected by UnitX:
