Cell & Pack Manufacturing

Cell Manufacturing Issues - Electrode Manufacturing Is Difficult Every step in battery production presents challenges, but some, like coating, drying, and slitting carry a significantly higher risk of defects. The heat map illustrates these critical areas, highlighting their likelihood of defects. Produces most scrap during ramp-up

MAJOR DEFECTS THAT CAN OCCUR DURING COATING AND DRYING OF ELECTRODES

Contamination occurs leading to cell failure (most relevant for mass production)

agglomerates

pinholes

contamination

inhomogeneous coating load

heavy edges

DESCRIPTION

BULK DEFECTS

closely packed clusters of the solid components

tiny holes or missing spots in the electrode coating

impurities of foreign substances

Inhomogeneous coating application

poor optimization of the slot die on the cross-web profile

EFFECT

SURFACE DEFECTS

mechanical failure of the separator; localized impedance rise and capacity loss

can affect cell performance due to localized regions where capacity balancing issues occur, potential Li plating

can cause fast battery degradation and internal short circuit ISC, lead to hi-pot failure 2

heterogeneous porosity of electrodes; capacity balancing issues within cell, potential Li plating

uneven calendaring, leading to electrode wrinkles, leading to cell failure

Sources: Mastering Ramp-up of Battery Production, Fraunhofer Both Figures but with internal edits*); 2 High-Potential Failure Analysis, Sotto; Detecting the foreign matter defect in lithium-ion batteries[...], Pan et al.

Extracted from the PDF; charts and images may read imperfectly.