Lithium magnesium alloys: a framework for investigating lithium alloy anodes for solid state batteries

Abstract

Lithium alloys have the potential to overcome anode-side challenges in solid state batteries. In this work we synthesize and characterize lithium-rich magnesium alloys, quantifying the changes in mechanical properties, transport, and surface chemistry that impact electrochemical performance. Increases in hardness, stiffness,adhesion, and creep are quantified by nanoindentation as a function of magnesium content. A decrease in diffusivity is quantified with chronopotentiometry and6Li PFG-NMR, and an increase in interfacial impedance due to the presence of magnesium is identified with electrochemical impedance spectroscopy which is correlated with XPS data. Throughout, changes in properties are linked to electrochemical performance. This work provides a framework to investigate other lithium alloy systems.