Scanning acoustic microscope images for the localization of defects inside dummy pouch cells

Abstract

The identification and location of critical defects inside battery cells before the performance decreases or safety issues arise remains a challenge. Here we show images acquired from Scanning Acoustic Microscopy (SAM) as a non-destructive testing methods for the 3D visualization of defects at different depths inside a pouch battery cell. A manufactured dummy pouch cell with 8 cathode sheets is used for this investigation. SAM using a 15 MHz transducer in reflection mode can detect defects with a lateral resolution of 150 µm in 2 min. The time intervals of each micrograph have a length of 30 ns. The images are acquired with a resolution of with a pixel dimension of 50 x 50 μm²/ pixel.