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

Abstract

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.