First-Principles Modeling of the Initial Stages of Organic Solvent Decomposition on LixMn2O4(100) Surfaces

Density functional theory and ab initio molecular dynamics simulations are applied to investigate the initial steps of ethylene carbonate (EC) decomposition on spinel Li0.6Mn2O4(100) surfaces. EC is a key component of the electrolyte used in lithium ion batteries. We predict a slightly exothermic EC bond-breaking event on this oxide facet, which facilitates subsequent EC oxidation and proton transfer to the oxide surface. Both the proton and the partially decomposed EC fragment weaken the Mn-O ionic bonding network. Implications for an interfacial film made of decomposed electrolyte on cathode surfaces, and LixMn2O4 dissolution during power cycling, are discussed.