Fraunhofer Research Institution for Battery Cell Production FFB
Fraunhofer Research Institution for Battery Cell Production FFB

Electrode production and validation for S-ALD coatings

Situation and motivation

Fraunhofer FFB is working on a reference project with the Dutch technology company Kalpana Systems to validate Superspatial Atomic Layer Deposition (S-ALD) in battery cell production. This innovative process allows electrodes to be coated with S-ALD particularly quickly and cost-effectively.

One promising field of application is the creation of artificial passivation layers (SEI) on anodes, which are crucial for the stability and charging capacity of battery cells. The aim of the project was to test the S-ALD coating and evaluate the effect at cell level.

Approach

Fraunhofer FFB was responsible for the selection of suitable electrode formulations, material procurement and the production of graphite-based negative electrodes (slurry mixing and slot die coating). An S-ALD layer was then applied to the coated electrode foils by Kalpana using a roll-to-roll process. Fraunhofer FFB then analyzed the optical, mechanical and electrical properties of the samples. For the electrochemical validation, button cells with S-ALD-coated negative electrodes and NMC-based positive electrodes were manufactured and comprehensively characterized. This included long-term and fast-charging tests (C-rate) to evaluate stability and performance.

Procedure

  1. Selection of a suitable anode formulation and material procurement
  2. Production of anode materials (slurry mixing and coating)
  3. Provision of the materials for the R2R-S ALD coating by Kalpana Systems
  4. Analysis of the coated materials, e.g. with regard to electrical conductivity
  5. Production and electrochemical characterization of button cells
  6. Carrying out long-term and rapid charging tests to investigate stability and charging capacity
© Fraunhofer FFB

Results

The results demonstrate the feasibility and potential of the approach. Initial experience has been gained and further areas for optimization have been identified. With a transfer to the FFB PreFab, it will be possible to further scale up the S-ALD technology in the future and make it usable for the battery industry.

Summary

  • Successful coating and initial validation of anode materials in the R2R-S-ALD process
  • Proof of potential for industrial use at cell level
  • Identification of further optimization fields for process and material use
  • Basis created for possible scaling of the technology in the battery sector using the "FFB PreFab"
Project partner

Kalpana Systems

Kalpana Systems is a technology company based in Rotterdam (Netherlands) that develops innovative solutions in the field of thin film coating. The focus is on the further development and industrialization of atomic layer deposition (ALD). With the Superspatial ALD (S-ALD) process, Kalpana enables particularly fast and cost-efficient coatings for applications in battery technology, photovoltaics, organic electronics and sustainable packaging.