2 research outputs found
Tracing the technology development and trends of hard carbon anode materials - A market and patent analysis
Methodology for the characterization and understanding of longitudinal wrinkling during calendering of lithium-ion and sodium-ion battery electrodes
"The manufacturing of lithium-ion battery (LIB) cells is following a complex process chain in which the individual process steps influence the
subsequent ones. Meanwhile, increasing requirements especially concerning the battery performance, sustainability and costs are forcing the
development of innovative battery materials, production technologies and battery designs. The calendering process directly affects the volumetric
energy density of an electrode and therefore of a battery cell. Calendering is still challenging as it causes high stresses in the electrode that lead
to defects and thus increased rejection rates. The interaction between electrode material and process as well as the formation of defects is still not
fully understood, especially when new material systems are used. In this context, the sodium-ion battery (SIB) is one post-lithium battery system
that is a promising option to overcome the limitations of conventional LIBs. Therefore, this paper presents a first material and machine
independent methodology to describe and understand the defect type longitudinal wrinkle, which mostly appears at the uncoated current collector
edge of an electrode and in running direction. The aim is to systematically characterize the longitudinal wrinkles according to their geometry.
The automatic data acquisition is carried out with a laser triangulation system and a 3D scanning system. The geometry values are calculated
from the raw data and correlated to selected process parameters. The methodology is applicable regardless of the material as shown by exemplary
results of NMC811 cathodes for LIB and hard carbon anodes for SIB. By using two different pilot calenders it is shown, that the data acquisition
can be carried out independently of the machine. The presented methodology contributes to finding solutions for the avoidance of longitudinal
wrinkling in any battery electrode and therefore to reducing the rejection rate.