Interplay Between the Dissolved Mn2+ and Solid Electrolyte Interphases of Graphite Anode

Abstract

Transition metal (TM) dissolution and crosstalk are one of the main degradation mechanisms for the capacity fading of lithium‐ion batteries (LIBs). Although significant efforts have been devoted to elucidating the origins of TM dissolution, its crosstalk effect on the anode interface is unclear, especially for its specific chemical state and electrochemical behavior. Herein, the interplay between the dissolved Mn2+ and the solid electrolyte interphases (SEI) on graphite anode is revealed by different characterization techniques, such as Raman spectroscopy, cryogenic transmission electron microscopy, electron energy loss spectroscopy, and time‐of‐flight secondary ion mass spectrometry. The results demonstrate that Mn2+ is inclined to coordinate with ethylene carbonate (EC), which is easily decomposed and generates organic‐Mn2+ species and gaseous byproducts. These gases disrupt the SEI structure, facilitate electrolyte infiltration, and induce continuous growth of the SEI layer. This study deepens the understanding of TM crosstalk on SEI properties and LIB performance, offering potential strategies for enhancing battery durability and performance.