Anion-Driven Solvent Degradation Networks in High-Concentration Battery Electrolytes

High-concentration electrolytes (HCEs) are increasingly investigated for next-generation Li-ion batteries (LIBs) due to their ability to form robust, inorganic-rich solid electrolyte interphases (SEI). While it is established that the SEI composition in HCEs is distinct from dilute electrolytes, the specific anion-mediated reaction networks that drive this transformation remain poorly understood. The com- plexity of these networks and the transient nature of the radical intermediates involved have precluded the development of a comprehensive mechanistic map of initial SEI formation. Here, the reaction networks governing anion-mediated electrolyte degradation are established using automated reaction discovery and microkinetic modeling (MKM). The study encompasses the decomposition pathways of ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), and acetonitrile