Electrical and lithium ion dynamics in Li2IrO3 from density functional theory study
Abstract
Layered Li2IrO3 has been investigated using first-principles calculations within the GGA and GGA + U schemes. Within the GGA + U approach, the calculated intercalation voltage (ranging from 3.2 V to 4.1 V) is found to be in good agreement with experiments. Electronic-structure analysis shows that the band gap of pure phase Li2IrO3 is ∼1 eV, which is indicative of semiconductor properties. Moreover, further studies of lithium diffusion in bulk Li2IrO3 show that unlike the two dimensional diffusion pathways in rock salt structure layered cathode materials, lithium can diffuse in a three-dimensional pathway in Li2IrO3, with moderate lithium migration energy barriers ranging from 0.24 to 0.81 eV.