The Crucial Role of Electrode Potential of a Working Anode in Dictating the Structural Evolution of Solid Electrolyte Interphase

Abstract The performance of rechargeable lithium (Li) batteries is highly correlated with the structure of solid electrolyte interphase (SEI). The properties of a working anode are vital factors in determining the structure of SEI; however, the correspondingly poor understanding hinders the rational regulation of SEI. Herein, the electrode potential and anode material, two critical properties of an anode, in dictating the structural evolution of SEI were investigated theoretically and experimentally. The anode potential is identified as a crucial role in dictating the SEI structure. The anode potential determines the reduction products in the electrolyte, ultimately giving rise to the mosaic and bilayer SEI structure at high and low potential, respectively. In contrast, the anode material does not cause a significant change in the SEI structure. This work discloses the crucial role of electrode potential in dictating SEI structure and provides rational guidance to regulate SEI structure.