The demand for improved Li-ion batteries (LIBs) has led to a growing interest in highly concentrated electrolytes (HCEs) as a solution to conventional LIB limitations. HCEs facilitate the formation of stable anion-derived solid electrolyte interfaces (SEI) through decreased solvent reduction reactions. However, understanding electrolyte decomposition is challenging due to the lack of an inclusive set of reaction channels available to simulate the initial steps of SEI formation. In this work, we are addressing this drawback by adapting and applying the Yet Another Reaction Program (YARP) methodology, developed by the Savoie group, focusing on solvents and dissolved anions from various salts suitable for HCEs. Reaction network prediction has the potential to reveal SEI formation mechanisms by analyzing transition states and thermodynamics, while also enhancing computational methods that integrate reaction kinetics into molecular dynamics simulations. As an initial case study, the anion-mediated reaction channels in typical Li-carbonate based electrolytes are characterized to understand potential electrolyte degradation mechanisms. The elementary reduction pathways involving various anions and ethylene carbonate solvent have been identified, along with the corresponding activation barriers. This study is further extended to explore the reduction of HCE compatible solvents and salts, leading to their decomposition through multiple pathways and the formation of various products including experimentally identified SEI contributing compounds. The diverse decomposition mechanisms of different solvents highlighted the role of the salt in mediating electrolyte decomposition as well as the complexity of SEI formation and its dependence on electrolyte components. These findings offer valuable insights into SEI formation in HCEs by providing a comprehensive map of the anion-mediated degradation pathways in this novel class of electrolytes.
