Structural and electronic properties of solid-state (LiMPO4∣γ-Li3PO4)[010] electrochemical interface (M = Fe and Co).

First principles density functional calculations are carried out to investigate the structural, electronic, and electrochemical properties of the bilayered nanocomposite, which is composed of Li M PO 4 ( M = Fe and Co) as a positive electrode and γ-Li 3 PO 4 as a solid-state electrolyte. The calculated interfacial energy reveals that the Li-O atomic layer terminated (010) Li M PO 4 surface gives better stability than its Fe-O layer termination, for constructing the solid state interface with γ-Li 3 PO 4 . Further, structural optimization shows that inter-layer distances at the interface and surface of the electrolyte are increased ≈0.1 and 0.06 Å, respectively, from its bulk value. Moreover, electronic structure calculations infer that the energy of top most occupied level in the electrode strongly depends on its thickness, whereas, this energy is almost constant for different thick electrolytes. Thus, our study suggests that by varying the thickness of Li M PO 4 -electrode, Li-ion vacancy formation and electrochemical performance of the nanocomposite can be altered favourably. [ABSTRACT FROM AUTHOR]