225kv or 450kv CT Scan - an EV Battery Module Comparison

Sometimes you have to make the best with what you have. Our best just got even better.

One of our first big CT projects years ago was scanning and sorting thousands of EV battery modules. CT at this magnitude was a new concept for our client. CT OEMs either said it wasn’t possible, or that it would take several hours to acquire high enough fidelity to analyze the data. We found a method requiring just 15 minutes.

While this was a great solution and solved our client’s issues, each battery required four scans at specific angles in order to penetrate the high linear density of the module. The benefit of the technique was increased resolution from the angled focus scan, but it was very data intensive with over 8,000 scans and provided no value other than in the area of interest.

We’ve tested and optimized comparison data between our 225kv Microfocus system and our 450kv Mesofocus. Results are presented below.

This view shows the original working CT data presented in Volume Graphics acquired by our 225kv Nikon Microfocus at a resolution of 122um.

There is great cell layer data but the layers quickly fade into noise. Any areas of interest in the body of the module were unable to be imaged.

This is a 15 minute scan with the fastest 225kv detector available (Varex 1621.)

The tear is shown in the bottom left view as the thick, dark diagonal line in the cell corner.

1. 122um Resolution
2. Partial Scan
3. 15 minutes (60 for four corners)

This view shows the working CT data presented in Volume Graphics acquired by our 450kv PXS Mesofocus at 102um resolution. The data was optimized for speed and failure detection, but with increased scan time we would be able to resolve the cell layer data too.

This is a 12 minute scan of the entire module.

The tear is shown to have expanded over the course of the two years since the initial scan.

1. 102um Resolution
2. Full Scan
3. 12 Minutes