Experimental Investigation of the Compaction Behavior of Battery Electrodes Using Instrumented Indentation and Calendering

In the manufacturing of battery cells, and
particularly in electrode production, the adjustment of suitable
process parameters on production equipment remains largely
an experience-driven and iterative task. This presents a
significant challenge, especially during the ramp-up of new
production lines. Such parameter adjustments are also required
when introducing new product variants or for continuous
process control to compensate for variations in input material
properties and tolerances. A model-based derivation of process
parameters from the desired product specifications is often not
directly feasible due to the complex material behavior and lack
of robust models.
This study aims to experimentally investigate the
elastoplastic behavior of a graphite-based battery anode
electrode during mechanical compression, as encountered in the
calendaring process. The focus lies on capturing the material
response immediately after unloading in order to understand
the relaxation behavior. Instrumented indentation and
laboratory-scale calendaring experiments are carried out using
planar indenters with surface areas of 5 mm² and 100 mm², as
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well as a cylindrical calender rollers with a diameter of 200 mm.
These setups are used to evaluate the influence of contact
geometry on force-displacement characteristics. The results
demonstrate that the compaction speed has a significant effect
on the extent of relaxation. These fundamental experimental
insights contribute to a deeper understanding of the timedependent
mechanical behavior of electrode materials.
Establishing such process knowledge is a critical step toward the
development of predictive process models that can support the
rapid and reliable adjustment of calendaring parameters in
future industrial applications.