Elucidating the cluster versus crystal growth of the Solid Electrolyte Interphase components*

The complexity of the Solid Electrolyte Interphase (SEI) at Li-ion batteries on graphitic electrodes, has triggered extensive deal of research due to its crucial properties for the long life of the battery. The SEI layer is composed by organic and inorganic species and results from the electrolyte decomposition on the electrode upon the first cycling of the battery. A stable SEI layer is crucial to maintain the chemical and mechanical stability of the electrode and the electrochemical stability of the electrolyte in order to prevent the irreversible capacity loss.
This work uses computational crystal structure prediction genetic evolutionary algorithm to simulate the nucleation, growth and the aggregation of the inorganic SEI products forming the SEI mosaic film. In depth investigation of the growth mechanisms of LiF and Li2CO3 starting from the first nucleation seed is undertaken. The energetics of the resulting cluster growth mode in compared to layer by layer growth mode at the graphite surface in different lithiation and surface termination states.