Electrode Development

for Lithium Ion Batteries

Additives

Properties of binders for aqueous and non aqueous slurries
Processing of conductive additives
Exploration of interactions between inactive electrode components

Process Technology

Dispersing of powders and stabilization of slurries
Aqueous processing of electrode slurries
Rheological characterization
Manufacturing of battery electrodes

Products

Cathodes and anodes for lithium ion batteries
Assembling of pouch cells
Investigation of the electrode structure
Electrochemical characterization

Batteries can only achieve their full potential if not only the active materials used, but also the other electrode components and their processing are taken into account. An important role is played by the inactive components that are added to improve the conductivity and mechanical properties of the electrodes. In the foreground of the investigations on electrode development are therefore binder and conductivity additives, whereby in particular their interactions with each other and the influence on the active material and the cell properties are considered. Current focus areas are the development of water-based paste systems and the determination of the additive distribution in the electrodes.

Efficient systems are available for the production of electrodes and laboratory pouch cells, which are based on industrial designs and production processes, but still allow a fast and flexible test procedure, since they are designed for a very low material usage.

Research Activities

	Stability of Slurries Segregation effects (sedimentation, agglomeration, binder migration) are the reason for many electrode defects ► Investigation of the impact of inactive electrode components on the stability of electrode slurries. Publication
	Aqueous Processing Usage of water as solvent is economical and ecological, but still causes processing problems and reduced cell properties ► Implementation of alternative binder systems and adaption of slurry preparation, drying and compaction process. Publication
	Electrode Manufacturing Electrode manufacturing processes provide a significant contribution to the costs of the cell ► Development of improved manufacturing methods, e.g. for solvent reduced production or electrodes with enlarged thickness. Publication
	Electrode Structure Electrode properties are strongly influenced by the local and overall distribution of electrode components ► Development of analytical methods which describe the electrode structure and enable the achievement of material - processing - property relationships. Publication

Electrode Manufacturing

of Laboratory Pouch Cells

Coating
Roll-to-roll coater (KTF-S, Mathis AG)
Doctor blade device
Working width max. 360 mm
Coating speed 0.1 to 2 m/min
Two drying zones (2 x 1 m)
Corona treatment

Calendaring
Roll-to-roll calendar (GKL, Saueressig GmbH)
Roll width 400 mm
Line load max. 1200 N/mm (at full width)
Working speed 1 to 10 m/min
Roll temperature max. 60 °C

Batch calendar (GKL, Saueressig GmbH)
Roll width 300 mm
Line load max. 500 N/mm (at full width)
Working speed 0.5 to 5 m/min
Roll temperature max. 150 °C

Cell Assembling
Dry room (dew point at cabin outlet <-50 °C )
Equipment for laboratory pouch cells
Standard cathode size 50 x 50 mm²
Typically monolayers (capacity app. 40 mAh)
Multilayer stacks feasible
Manual assembling up to 30 cell/d