Atomic layer deposited coatings to significantly stabilize anodes for Li ion batteries: effects of coating thickness and the size of anode particles

A study of the effect of thickness of alumina coating on the electrochemical performances of various sizes of SnO2 electrodes has been systematically studied in this paper. It is found that the different volume changes in various sizes of SnO2 electrodes can be suppressed by optimized thickness of Al2O3 coating layers, with a range from less than 1 nm to up to 3 nm deposited by atomic layer deposition (ALD), which have significant impact on the electrochemical behaviour of the composites. The well-defined and optimized Al2O3 layer could not only relieve mechanical degradation and improve cycling stability, but also form an artificial solid electrolyte interphase (SEI) layer to prevent the chemical reaction between SnO2 and the electrolyte, leading to improved electrochemical performances compared with bare SnO2 electrodes.