Structural, Electronic, Elastic and Dynamical Properties of MCO3 (M: Mn, Co, Ni) Precursor Materials for Li-Ion Batteries: A First-Principles Study

Abstract

This communication reports first-principles calculations on the structural, thermodynamic, electronic, elastic and dynamic properties of transition metal carbonates, MCO3 (M=Mn, Co, Ni) at 0 K. These materials are projected to be excellent candidates as precursors for advanced cathode materials in rechargeable lithium-ion batteries which employ an NMC chemistry. We have employed the plane-wave pseudopotential method framed within the density functional theory (DFT) as embedded in the VASP code. The exchange-correlation functional of Perdew, Burke and Ernzerhof (PBE) was used. Moreover, the Hubbard U-correction in the rotationally invariant form was applied to improve the description of the strongly correlated 3d electrons of the transition metals. The structural cell parameters were calculated to 96% agreement with the experimental data, warranting the robustness of the approach employed. All MCO3 crystal systems have negative enthalpies of formation, indicating thermodynamic stability leading to good cycling performance and safety. All the elastic constants for the considered transition metal carbonates satisfied the necessary stability conditions, indicating mechanical stability. Moreover, negative vibrations are not observed in the high symmetry directions of the Brillouin zone, suggesting dynamical stability.