Evolution of the Dynamic Solid Electrolyte Interphase for Halogen-Containing Vs Non-Halogen Mg Electrolytes

Abstract

High-performance electrolytes play a pivotal role in the development of Mg batteries. Grignard-type electrolytes were considered a potential electrolyte for commercial application in Mg batteries. However, due to the limited number of high-voltage cathodes and the corrosion of the battery’s components, non-halogen Mg-based electrolytes have received considerable attention recently. Although some studies reported film formation and passivation at the Mg electrolyte/electrode interface, there is a lack of in-depth analysis of the interfacial evolution for multivalent battery systems, which governs the performance and longevity of the Mg battery. In this study, our aims are to investigate the evolutionary process of the solid electrolyte interphase (SEI) at the Mg interface and to compare reaction mechanisms for halogen-containing versus non-halogen Mg electrolytes. The work presented here offers an in-depth qualitative and quantitative analysis of the SEI evolution.