BYK Additives for electrodes of Li-Ion Batteries
For electrodes of Li-ion batteries, these additives can be used to stabilize conductive carbon additives (e.g. carbon black, carbon nanotubes, or graphene) and active material particles in the coating slurries. The dispersants can also be used to formulate concentrates of conductive carbon additives and increase their storage stability.
|Electrostatic Stabilization||Steric Stabilization|
Figure: Different kinds of particle stabilization by polymeric dispersing additives
Function in the electrode
|Cross sectional SEM-images of LFP-cathodes:|
Control (w/o dispersant) Containing BYK dispersant
The addition of a small amount of polymeric dispersant to the coating slurry improves the homogeneity and enables formulation with 5–15wt.% increased solid content compared to slurries without dispersing additives by similar viscosities.
The more homogeneous distribution of the conductive carbon additives is reflected in improved electrode performance (e.g. cycling stability and rate performance), and the higher solid content of the slurries decreases the energy required for electrode drying.
|CC-Discharge Capacity (w/o and with BYK Product in LFP Cathode)|
Properties of polymeric dispersants:
- Electrochemically stable
- Stabilize the conductive carbon additives (e.g. carbon black) and active material in electrode slurries
- Enable higher solid content (5–15%) of slurries and thus improve productivity
- Partially substitute the conventional binders and consequently, compared to systems w/o dispersants, no loss of gravimetric energy density is observed
- Improve electrode coating homogeneity
- Improve electrode performance in terms of rate performance and cycle life
The synthetic clay LAPONITE-RD manufactured by BYK has been investigated as a functional additive in electrodes of lithium-ion batteries. LAPONITE acts as a rheology additive in the aqueous electrode coating slurry as well as a lithium-ion conducting additive in the electrode. The synergistic effect of LAPONITE in combination with sodium carboxymethylcellulose (CMC) was used to reduce the necessary amount of thickening agent to formulate stable aqueous electrode coating slurries. Electrodes which contain mixtures of LAPONITE/CMC as a binder show improved cycle life and rate capability compared to conventional electrodes.
Composition of anode coatings with/without LAPONITE
Using LAPONITE as an additive for electrodes appears to be a promising approach to improving the manufacturing process and product performance of lithium-ion cells. The positive product properties and effects are:
- High purity
- Improved slurry stability due to synergistic effect with organic co-thickeners
- Improved electrode mechanical strength
- Improved electrode wettability with electrolyte
- Improved C-rate performance of electrodes
- Improved cycle life of electrodes
For detailed information, please read our paper on LAPONITE-RD as an additive in electrodes of Li-ion batteries and our LAPONITE brochure.
RESULT: Higher capacity and excellent cycle stability
How can we make you mobile? You can obtain detailed information and examples of test results that reveal the positive effect of dispersants on the process and product properties of a graphite anode or confirm the increasing solid content due to viscosity reduction from our battery specialists at Battery.BYK@. altana. com