Computational Studies of Lithium Manganese and Nickel-Manganese Oxide Spinel Surfaces

LiMn₂O₄ is ideal as a high-capacity Li-ion battery cathode material by virtue of its low toxicity, low cost, and the high natural abundance of Mn. However, this material suffers from Mn dissolution problem that not only induces capacity fade, but can also poison the anode. Several approaches have been devised to mitigate Mn dissolution, including doping, coatings, and even particle shape control. Previous studies have shown that the electrochemical performance and cycling stability of these materials depend not only on the composition, but on the particle morphology as well. Simulations of the structure of low index surfaces of the spinel-structured LiMn₂O₄ and its derivatives, such as the high voltage LiNi_0.5Mn_1.5O₄ spinel have been performed within the GGA+U approximation, and ab-initio molecular dynamics. New insights resulting from this work, including interactions with electrolytes, will be presented.

This work was supported as part of the Center for Electrochemical Energy Science, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences.