High-Speed Coating of Primer Layer for Li-Ion Battery Electrodes by Using Slot-Die Coating

A reduction of the inactive components can increase the energy density and reduce production cost of Li-ion batteries. But an effective reduction of the binder amount also negatively affects the adhesion of the electrode. Herein, slot-die coating of a primer layer for Li-ion anodes is investigated. It is shown that the use of a primer layer with only 0.3 g m(-2)can increase the adhesive force by the factor of 5 as well as the cell performance for anodes with low binder content. The process limits for a stable, defect-free primer coating are investigated at coating speeds of up to 550 m min(-1). The limits coincide both for a setup without vacuum box and with vacuum box with theory-based equations. By using a vacuum box, the minimum wet film thickness can be reduced by half.