First-principles study of the nano-scaling effect on the electrochemical behavior in LiNi 0.5 Mn 1.5 O 4

Nano-scaling of electrode materials is often used in battery applications to enhance performance, particularly relating to rate capability. However, for the high-voltage spinel LiNi 0.5 Mn 1.5 O 4 conflicting results have been reported on the benefits of nano-scaling. In this study, we present first-principles calculations to investigate the effect of nano-scaling on LiNi 0.5 Mn 1.5 O 4 , specifically focusing on the roles and coupling between surface stability, cation ordering and phase behavior. We calculate and compare the surface energy for the low index facets (100), (110), and (111), and find that the most stable facet is dependent on the cation ordering at the surface layer. In this context, we predict a spontaneous surface reconstruction in the cation-ordered structure which leads to a deviation from the perfect surface cation ordering and results in an enhanced accessibility to solid solution behavior as a function ...

Eunseok Lee and Kristin A Persson

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