Nucleation Mechanisms of Electrodeposited Magnesium on Metal Substrates

Abstract

Magnesium rechargeable batteries (RMBs) are a promising alternative to lithium-based ones. However, a major challenge in their advance concerns the development of aprotic electrolytes from which magnesium can be electrodeposited with high efficiency and without the formation of dendrites. Of note, the mechanism of the magnesium electrodeposition from aprotic electrolytes remains largely unexplored. In this study, we propose a combined experimental and theoretical approach based on the Scharifker-Hills (S−H) mathematical model for the potentiostatic transients to analyse the nucleation and growth of magnesium during electrodeposition in order to shed light on the nucleation process and increase battery safety and cycle lifetime. The model is used to investigate the electrodeposition of magnesium from a Magnesocene (MgCp₂)-based electrolyte onto metal current substrates such as copper, nickel, aluminium and stainless steel.