ECS-RS Economic Convex/Concave Metal-Type Electrode Sheet Cutter (L120mm x W100mm) for Pouch Cells (Ar Glovebox Compatible), ERSPCECCMESC

An Electrode Sheet Cutter with a Convex/Concave Metal Die is a high-precision laboratory instrument used to punch out precise electrode discs or shapes from coated continuous foils (e.g., copper or aluminum current collectors coated with active materials). Unlike simple impact punches or flat blade cutters, a convex/concave matched metal die uses an engineered geometric curvature on the cutting faces to optimize the shearing force distribution. This minimizes structural defects along the electrode perimeter.

In standard flat-on-flat punching, the entire circumference of the cutting edge hits the electrode sheet at the exact same millisecond. This requires a high peak force and can cause several microscopic defects: (1) Foil Burrs: Microscopic metal shards projected from the edge of the copper or aluminum current collector foil. In a battery cell, burrs can easily pierce the thin separator, causing an internal short circuit or high self-discharge. (2) Active Material Delamination: The sudden, high impact shock wave can cause brittle active materials (like high-nickel NMC or sulfur-sulfide composite cathodes) to crack and peel away from the current collector edge, reducing the active areal capacity.

A convex/concave layout solves this by introducing a micro-angled or curved cutting edge. As the upper die (convex) descends into the lower die (concave), it initiates contact at a single point and systematically shears across the material circumference, much like a pair of scissors. This continuous, progressive cut drastically reduces peak cutting force, eliminates edge deformation, and prevents delamination.

References:

S. Chen, et al., Critical Parameters for Evaluating Coin Cells and Pouch Cells of Rechargeable Li-Metal Batteries, Joule, 2019, 3, 1094-1105

T. Marks, et al., A Guide to Li-Ion Coin-Cell Electrode Making for Academic Researchers, J. Electrochem. Soc., 2011, 158, A51.