First-principles calculations to investigate electrochemical performance of the LiYO3 cathode for Li-ion battery

Abstract

In this work, the structural, electronic, optical, magnetic, and thermodynamic properties of LiYO₃ are investigated by employing first-principles calculations based on the density functional theory (DFT). LiYO₃ is ferromagnetic material having half metallic electronic structure. For LiYO₃ compound, the obtained values of the indirect band gap are 2.1 eV for GGA-PBE and 2.54 eV for TB-mBJ, respectively. Optical parameters, such as dielectric functions, refractive indices, extinction coefficient, optical reflectivity, absorption coefficients, and optical conductivities, were calculated for photon energies up to 40 eV. Electronic and optical properties are calculated by (TB-mBJ and GGA-PBE) approaches. The thermodynamic properties were calculated using a quasi-harmonic Debye model to account lattice vibrations. In addition, the influence of temperature and pressure effects was analyzed on bulk modulus, volume, heat capacities, and Debye temperature. The equilibrium voltage over a full cycle (V_cell), was calculated as 4.14 V, and the energy density was determined at 772 Wh/kg. Due to all these properties, LiYO₃ is a candidate to be used as a cathode for lithium batteries.