First principle calculations on structural, electronic and transport properties of Li2TiS3 and Li3NbS4 positive electrode materials

Abstract

First principle calculations based on density functional theory have been performed on lithium containing transition metal sulfides Li 2 TiS 3 and Li 3 NbS 4 which are recently identified as novel positive electrode materials for rechargeable Li ? batteries. The calculations were performed to investigate the structural stability, electronic and transport properties of Li 2 TiS 3 and Li 3 NbS 4 along with their corresponding delithiated phases LiTiS 3 and Li 2 NbS 4. In this study it has been observed that these lithium containing sulfur materials maintain their facecentered cubic structure upon extraction of Li ?. To calculate the structural stability and volume change due to lithium extraction, the total energies of Li 2 TiS 3 , Li 3 NbS 4 and their corresponding delithiated phases LiTiS 3 and Li 2 NbS 4 have been computed by applying full potential linearized augmented plane wave (FP-LAPW) method implemented in WIEN2K. The equilibrium structural parameters for all the phases were determined by achieving total energy convergence. These electrode materials exhibit very small percentage of volume change with change in Li ? concentration which accounts for excellent structural stability. The computed band structure along high symmetry lines in the Brillouin zone, total and partial density of states clearly reveals that the extraction lithium from these electrode materials does not change their metallic nature. The electronic conductivities of both lithiated and delithiated phases have been calculated by employing BoltzTrap which can be interfaced with WIEN2K. The topological distributions of electron charge density at various critical points within the system were analyzed with the use of CRITIC code which is based on Bader's theory of atoms in molecules (AIM). From the charge density calculations, it was observed that, there is strong ionic bond and weak covalent bond between atoms of the compounds Li 2 TiS 3 and Li 3 NbS 4. But the ionic bond nature was found to decrease in the delithiated phases LiTiS 3 and Li 2 NbS 4. The calculated values of electronic conductivities and discharge voltages for both electrodes are found to be in accordance with the recent experimental reports.

Implications of Oxygen–Sulfur Exchange on Structural, Electronic Properties, and Stability of Alkali‐Metal Hexatitanates

“…Furthermore, research into solid electrolytes for all‐solid‐state batteries has seen a rapid rise in recent years. Both oxide and sulfide compounds, such as Li 10 GeP 2 S 12 , Li 10 SnP 2 S 12 , Li 7 La 3 Zr 2 O 12 , Li 3 OCl, and Li 3x La 2/3− x TiO 3 have been investigated as solid‐state electrolytes . Li 2 TiS 3 and Li 3 NbS 4 have also been tested as positive electrodes in the search for the best superionic conductors for all‐solid‐state batteries …”

“…Both oxide and sulfide compounds, such as Li 10 GeP 2 S 12 , Li 10 SnP 2 S 12 , Li 7 La 3 Zr 2 O 12 , Li 3 OCl, and Li 3x La 2/3Àx TiO 3 have been investigated as solid-state electrolytes. [20][21][22][23][24][25][26][27][28][29] Li 2 TiS 3 and Li 3 NbS 4 have also been tested as positive electrodes in the search for the best superionic conductors for all-solid-state batteries. [29] The dimensionality of the alkali-ion diffusion path has important consequences in the macroscopic conductivity of a battery material.…”

“…[20][21][22][23][24][25][26][27][28][29] Li 2 TiS 3 and Li 3 NbS 4 have also been tested as positive electrodes in the search for the best superionic conductors for all-solid-state batteries. [29] The dimensionality of the alkali-ion diffusion path has important consequences in the macroscopic conductivity of a battery material. In this context, the design of one-dimensional or tunable structures for alkali diffusion is highly required for the development of energy storage and battery technologies.…”

Investigation of Zinc and Chromium Substitution Nickel-rich LiNi1−x−yZnyCrxO2 Cathode Materials to Improve the Redox Reaction of Lithium-ion Battery: A First-principles Study

“…The calculations involve the elements 6 li, 6 Ni, and 12 O and perform z E-mail: ahmadusmandp@gmail.com; gmrai@gcu.edu.pk within a 2 × 1 × 1 supercell. 26,27 These calculations attempt to optimize the structural properties and investigate the electronic properties of the supercell. This supercell is divided into interstitial regions and muffin-tin (MT) spheres, with each atom assigned a suitable MT sphere radius (RMT) to ensure that there is no overlap.…”

Basic guidelines of first-principles calculations for suitable selection of electrochemical Li storage materials: a review

“…The XCrySDen 62 and VESTA 63 packages can be used to calculate the charge density distribution. In a recent study, 64 the ionic bonding among Li + , Ti 4+ , and S 2 − was investigated by analyzing the localized charge distribution observed in a contour plot of the valence charge density of Li 2 TiS 3 (anode) along (001), as shown in Fig. 6a.…”