Computational Study of O2/Li+-O2- Redox Reactions in Li-air Batteries
Emily Crabb, Massachusetts Institute of Technology
Lithium-air batteries are an active area of research because of their potential to have a much higher energy density than traditional lithium-ion batteries. However, they are not yet commercially viable due to poor efficiency, high charging voltages and low cycle lifetimes. Experimental studies of Li-air batteries with aprotic solvents have shown that the O2 reduction starts when superoxide (O2-) forms in solvent and reacts with Li+ to form lithium superoxide (Li+-O2-)1. Solid Li2O2 then forms as the final discharge product on the cathode. Recent experimental work has suggested that a better understanding of the factors governing the behavior of the lithium superoxide in solvent could help control the discharge at the cathode1. We are therefore modeling the interactions of the Li+ and O2- ions in various common solvents and studying properties such as the clustering behavior of Li+-O2- using density functional theory calculations and ab initio molecular dynamics simulations. Preliminary results from these explicit solvent calculations will be presented and discussed. 1D.G. Kwabi, V.S. Bryantsev, T.P. Batcho, D.M. Itkis, C.V. Thompson, Y. Shao-Horn, Angew. Chem. Int. Ed. 2016, 55, 3129.
Abstract Author(s): Emily Crabb, Graham Leverick, Yang Shao-Horn, Jeffrey Grossman