First Principles Modeling of the Initial Stages of Organic Solvent Decomposition on Li(x)Mn(2)O(4) (100) Surfaces

TL;DR

This study uses density functional theory and molecular dynamics to explore how ethylene carbonate decomposes on Li(Mn)2O4 surfaces, revealing initial bond-breaking and implications for battery cathode stability.

Contribution

It provides the first detailed atomic-level modeling of electrolyte decomposition on Li(Mn)2O4 cathode surfaces, highlighting initial reaction steps.

Findings

EC bond breaking is slightly exothermic on the surface

Proton transfer weakens Mn-O bonds

Decomposition impacts interfacial film formation and dissolution

Abstract

Density functional theory and ab initio molecular dynamics simulations are applied to investigate the initial steps of ethylene carbonate (EC) decomposition on spinel Li(0.6)Mn(2)O(4) (100) surfaces. EC is a key component of the electrolyte used in lithium ion batteries. We predict an 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 interfacial film made of decomposed electrolyte on cathode surfaces, and Li(x)Mn(2)O(4) dissolution during power cycling, are discussed.