CATL Implementation Case | Double-Sheet Detector Solves Overlap Issue on Lithium Battery Laminator

Project Background

The laminator most often used is the alternating stacking of positive and negative electrodes. It uses a continuous separator folded in a Z-shape by the laminator, and inserts positive and negative electrode sheets intermittently in the separator layers to form the stack. During picking of electrode sheets, the robot arm may grab two positive or two negative sheets at once; incorrect plate thickness can easily damage the mold and threaten production.

Project Objective

Objective: Accurately and effectively detect double-sheet overlaps.

Challenges: 1. Battery sheets are relatively small; 2. Small thickness; 3. Limited installation space inside the laminator.

Solution

Considering the small and thin characteristics of lithium battery electrode sheets, this solution uses Atonm Double-Sheet Detector MDSC-1000L (Lithium Battery Edition), specially designed for small and thin sheets. It offers high detection accuracy and fast response without requiring long dwell time. This model is specifically designed for the lithium battery industry.

Double-sheet detection sensor

When the robot arm places the sheet within the detector range, the double-sheet sensor is moved into the detection position to protect the sensor and avoid collisions during feeding. If the detector returns a single-sheet signal, the robot extends the pickup arm to take the sheet; if a double-sheet signal is detected, the robot stops and an alarm is issued.

The product consists of a controller and sensor. The controller processes the current signals while the sensor transmits and receives magnetic field signals. Working principle: two sensors form an electromagnetic field when powered. When a metal sheet enters the field, different thicknesses induce different voltages; the controller analyzes the current difference to determine whether the sheet between the probes is a single sheet or double sheet.