It is commonly believed that the formation of a solid-electrolyte interphase (SEI) is the main reason for improved electrode performance in rechargeable batteries. However, herein we present a new interfacial model that may change the thinking about the role of SEI, which has prevailed over the past 2 decades. We show that the varied desolvation behavior of mobile ions, which depends on the solvation structure determined by multiple factors (e.g., cations, solvent, anions, and additives) is a critical factor for electrode stability besides the SEI. This interfacial model can predict the intercalating species in graphite electrodes (i.e., Li+ (de)intercalation or Li+-solvent co-insertion) in different types of electrolytes (e.g., carbonate-, ether-based electrolyte). The generality of our model is further demonstrated by its ability to interpret the variable lithium plating/stripping in different electrolytes. Our model can predict electrode performance through the proposed cation-solvent interactions and desolvation behaviors and then help develop new types of electrolytes for mobile (ion) batteries.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: The research reported in this publication was supported by King Abdullah University of Science and Technology (KAUST). The simulations were performed on the KAUST supercomputer. The authors also acknowledege fruitful discussions with the research scientists at Huzhou Kunlun Power Battery Materials Co., LTD.