posted on 2024-02-27, 18:55authored byIsmail A. M. Ibrahim, Chan-Yeup Chung
Lithium-ion batteries find extensive applications in
numerous electronic
devices and have gained significant attention in recent years. Furthermore,
the evaluation of the intrinsic properties of cathode materials is
crucial for their practical applications. Hence, utilizing first-principles
calculations based on density functional theory and a hybrid functional
approach, we conducted a comprehensive investigation into the structural,
dynamical, mechanical, electronic, and electrochemical properties
of rutile-related LiM2SbO6 (M = Sc, Fe) channel
structures. We considered various crystal structures including the Pmn21 symmetry with Li-tetrahedrally coordinated
and the Pnn2 symmetry with Li-octahedrally coordinated
and different M arrangements. The Pmn21 crystal structures are more preferred over the Pnn2 crystal structures. Additionally, the Pnn2 configurations
of LiSc2SbO6 were found to be dynamically unstable.
LiSc2SbO6 has a higher calculated voltage than
LiFe2SbO6, with cell voltages ranging from 3.03
(4.70) to 4.92 (5.61) V by using the PBE (HSE06) functional. Furthermore,
lithiated LiFe2SbO6 configurations exhibit enhanced
electronic conductivity compared to LiSc2SbO6 in Pmn21 symmetry. For LiSc2SbO6 in the Pmn21 symmetry,
the Li diffusion barrier is 0.98 eV, while for LiFe2SbO6 configurations, it ranges from 0.45 to 1.19 eV. Configurations
with higher barriers are expected to have poor Li-ion conductivity
and may require synthesis as nanoparticles to enhance Li transfer.
This study may provide insights for developing cathode materials in
lithium-ion battery applications.