Structural,Electrical,and Lithium Ion Dynamics of Li2MnO3 from Density Functional Theory

The layered LiMnOis investigated by using the first-principles calculations within the GGA and GGA+U scheme,respectively.Within the GGA+U approach,the calculated intercalation voltage(ranges from 4.5 V to 4.9 V) is found to be in good agreement with experiments.From the analysis of electronic structure,the pure phase LiMnOis insulating,which is indicative of poor electronic-conduction properties.However,further studies of lithium ion diffusion in bulk LiMnOshow that unlike the two-dimensional diffusion pathways in rock salt structure layered cathode materials,lithium can diffuse in a three-dimensional pathway in LiMnO,with moderate lithium migration energy barrier ranges from 0.57 to 0.63 eV.