Evaluating Different ALD Techniques on NCM811 Cathodes to Mitigate Degradation and Improve Cycle Life

We used two different techniques of atomic layer deposition (ALD) to prepare AlO$_x$-coated LiNi$_{0.8}$Co$_{0.1}$Mn$_{0.1}$O$_2$ (NCM811) materials as cathodes for Li-ion batteries. The first approach was to use a fluidized bed reactor in order to coat the NMC811 powder before electrode film preparation and calendering with the goal of obtaining a dense coating on each particle of this powder. The second approach was to coat the electrode after film preparation and calendering by spatial ALD, with the possibility to prepare gradients of the coating material. We present an in-depth structural characterization of the prepared electrodes and their electrochemical performance, and we reveal the advantages and disadvantages of both approaches.