Royma RMCLT1850 scales inline CT for large cylindrical cells

Royma offers the RMCLT1850 as inline CT for large cylindrical cells: a fully automatic station that measures electrode overhang and internal gaps on every cell at a resolution below 20 µm. For the 46800 format, the RMCLT1850 runs a 160 kV, 700 W X-ray source, and two parallel sources inspect 28 cells per minute at a stated 95 % OEE.

The station sorts out-of-tolerance cells from the production stream without operator review. Throughput is set by the number of parallel X-ray sources, so the configuration follows the cell format and the target rate of the line. For battery lines that already use 2D X-ray, the RMCLT1850 adds the 3D measurement that a projection image cannot deliver.

2D X-ray screens, 3D CT measures

A 2D X-ray image is a single projection through the whole cell. In a wound cylindrical cell, dozens of anode and cathode layers lie on top of each other in that projection, and their edges overlap. That is fast and useful for a first check, but it leaves the decisive distances open. The RMCLT1850 reconstructs a 3D data set from a 180° scan of each cell, so every electrode layer can be measured on its own.

From that data set, the RMCLT1850 reports three results automatically for every cylindrical cell:

• the gap between the cell can and the electrodes
• the gap between the cell top and the electrodes
• the overhang distance from anode to cathode

These are the features that decide whether a cell is in tolerance. The measurement runs at a resolution below 20 µm, and the sort decision follows directly from it. Combining both methods on one line uses each where it is strongest: 2D X-ray for a quick look, inline CT for the measured go or no-go result.

“A cell line can keep 2D X-ray where it is fast enough and use the RMCLT1850 for the measurement that decides whether a cell ships,” says Gabor Szabo, Sales Director Europe, Royma Europe. “That gives every cylindrical cell a measured 3D result at the rate of the line.”

Parallel X-ray sources match throughput to cell size

The RMCLT1850 is configured per cell format rather than built around one fixed source. For 46800-format cells, it uses a 160 kV, 700 W X-ray source with a 180° scan in 15 s plus 2 s for loading and unloading. One source delivers 14 cells per minute at a stated 95 % OEE; two sources deliver 28 cells per minute.

Smaller cells scan faster. For the 21700 format, the RMCLT1850 uses a 225 kV open microfocus tube with a 180° scan in 3 s plus 2 s for handling. One source delivers 72 cells per minute; two, three and four sources deliver 144, 216 and 288 cells per minute.

This scaling is the core of the design. Large-format cells need more penetration and a longer scan, so the line rate is reached by running sources in parallel instead of shortening the scan. A plant specifies the number of sources its target rate needs and keeps the same inspection method across cell formats.

A complete station from barcode to NG store

The RMCLT1850 is a closed line segment, not a laboratory instrument placed beside the line. Each cell passes a barcode scanner, a loading robot, the X-ray source and rotating fixture, the detector, an unloading robot and an automatic NG sorter with NG storage. Loading, handling, scanning, analysis and sorting run fully automatically.

Every scan result is tied to the barcode of one cell. Process engineers therefore get a complete record of overhang and gap values from the first day of series output. Trends across shifts become visible and can be traced back to winding and assembly parameters.

“Large-format cells need more X-ray power and more scan time per cell,” adds Szabo. “With parallel sources, the RMCLT1850 keeps the full 3D measurement and still matches the rate of the line.”

More on Royma inline CT for batteries: Inline CT · 2D X-ray · Batteries · RMCLT1850 for cylindrical-cell lines

Test scans available

Royma Europe offers test scans of customer cylindrical cells and an evaluation of the source configuration for your target line rate.

Contact: Gabor Szabo, Sales Director Europe, Royma Europe – gabor_szabo@roymatek.eu – +49 15156503316 – www.roymatek.eu

Royma Europe, Leibniz Universität Hannover – Institut für Produktentwicklung und Gerätebau, Gebäude 8143, An d. Universität 1, 30823 Garbsen, Germany.

About Royma: Royma Industrial CT develops and builds industrial X-ray and computed tomography systems, from 2D X-ray to horizontal, gantry, planar and inline CT.