Density Functional Theory Investigation of Mixed Transition Metals in Olivine and Tavorite Cathode Materials for Li-Ion Batteries

Abstract

Lithium-ion batteries (LIBs) are widely used in various electronic devices and have garnered a huge amount of attention. In addition, evaluation of the intrinsic properties of LIB cathode materials is of considerable interest for practical applications. Therefore, through first-principles calculations based on the density functional theory, we investigated the structural, electronic, electrochemical, and kinetic properties of mixed transition metals, that is, Ni-substituted LiMnPO4 (LMP) and LiMnPO4F (LMPF) cathode materials, that is, LiMn0.5Ni0.5PO4 (LMNP) and LiMn0.5Ni0.5PO4F (LMNPF), respectively, which have not been extensively studied. We also evaluated their delithiated phases, that is, Mn0.5Ni0.5PO4 (MNP) and Mn0.5Ni0.5PO4F (MNPF). Our calculations suggest that Ni substitution significantly affected the structural and electrochemical properties. After Li insertion, the MNPF unit-cell volume increased by about 8%, lower than that of pristine MnPO4F. The Li intercalation voltage also increased in LMNP (4.27 V) and LMNPF (5.23 V). In addition, the migration barrier was calculated to be 0.4 eV for LMNPF, lower than that of LMPF. This study may provide insights for developing LMNP and LMNPF cathode materials in LIB applications.

Potassium Nickel Iron Hexacyanoferrate as Ultra-Long-Life Cathode Material for Potassium-Ion Batteries with High Energy Density

“…First-principles calculations were performed using DFT methods − with a plane-wave basis set code, QUANTUM ESPRESSO software package. , The spin-polarized generalized gradient approximation (GGA) with the Perdew, Burk, and Ernzerhof (PBE) exchange–correlation functional was applied to all calculations . According to previous literature, the Hubbard parameters (GGA+U) for Fe and Ni were 4.3 and 6.1 eV. , The norm-conserving pseudopotentials for all elements were generated using OPIUM.…”

Validating the Structural (In)stability of P3- and P2-Na0.67Mg0.1Mn0.9O2-Layered Cathodes for Sodium-Ion Batteries: A Time-Decisive Approach

“…The Brillouin zones were sampled using a k -point mesh of 1 × 2 × 1 and 1 × 5 × 1 for P2 and P3 structures, respectively. Subsequently, the optimized structures were subjected to the density of states (DOS) calculations, where the DFT + U method was applied with an on-site potential U of 3.9 eV for Mn and also for bond-valence sum (BVS) calculations using the softBV program. , In addition, environmental stability studies were also conducted for both structures by simulating the interaction of their surfaces with water molecules using the Grimme-D3 functional (vdw_corr = “grimme-d3”), which takes into account the physical van der Waals interaction, which is also implemented in QE. The VESTA program was used to visualize the optimized crystal structure along with the estimated Na diffusion path obtained from BVS calculations …”

High-Specific-Capacity and High-Performing Post-Lithium-Ion Battery Anode over 2D Black Arsenic Phosphorus

“…Importantly, it is noteworthy to point out that regardless of the type of rechargeable batteries, Li-ion or post-Li-ion batteries, the physical, chemical, and electrochemical properties of the material utilized in both the anodes and cathodes, such as outstanding cyclability, high electronic conductivity, and great specific capacity, is a vital and decisive element in the evaluation of the battery’s performance. − Despite the thorough exploration of a wide variety of positive electrode materials, the state of the art on negative electrode materials has been considerably hampered. − Many different materials were experimentally and theoretically demonstrated to be suitable candidates for Li-ion batteries, such as group IVA and VA compounds-based alloying and dealloying, − nanostructured materials, carbon-based materials, ,, and metal oxide materials . However, these C-based compounds such as graphite were significantly upgraded with respect to both safety and cycling efficiency, and they proved inadequate for use as an anode material to support post-Li-ion batteries.…”