Interview with Thomas Devahif (ARK)

Can you tell us more about your organsiation’s role in greenSPEED?

As a producer of specialty materials, ARKEMA can supply and develop new materials adapted to dry-process and high silicon content anodes. Based on this know-how in the development of high-performance polymers, ARKEMA provides binder materials for electrodes that can be manufactured through dry process. ARKEMA can adapt its material to improve adhesion to the current collector.

As ARKEMA is able to produce high purity lithium salts, we also provide to our partners electrolyte formulations to improve cyclability of cell using silicon anodes.

When it comes to the collector foils and adhesion, what challenges are you facing in the course of greenSPEED in comparison to State-of-the-Art technologies?

To manufacture good electrodes, all the components (binder, active material and conductive agent) must be homogeneously dispersed and coated onto the current collector. In the State-of-the-Art technologies, the mixing of components (named slurry) is done using a solvent (NMP) which is hazardous. Using a solvent is the easiest way to disperse the binder well and distribute it homogeneously around the components, and once it’s coated on current collector, the binder can easily come into contact with the aluminium.

In the dry process, we don’t have this step of binder dissolution anymore, so we have to ensure that the binder can still be well dispersed around the active material and the conductive agent first, and still able to generate good adhesion with the metallic collector. So we have to develop a binder that can easily coat the surface of the active and conductive materials without creating agglomerates, while keeping a high adhesion level on metal.

Why do you think that projects such as greenSPEED are important for the European Battery Production?

As mentioned, NMP is a huge disadvantage of today’s cathodes manufacturing. This solvent is toxic and needs to be removed through a drying step which consumes energy and has to be collected at the end of the process (increasing the energy consumption).

Promoting green process avoiding toxic solvent and limiting energy consumption is an important challenge that every European company has to face. Decreasing manufacturing impacts of battery will be also a way to promote green mobility.