Strategy for enhancement of magnesium ion diffusion in a vanadium tetra sulfide-layered structure for rechargeable magnesium batteries

Abstract

Theoretically Higher volumetric capacity, natural abundance, lower cost, dendrite free and ecofriendly Rechargeable Magnesium Battery System (RMBS) is considered as the most promising candidate for future commercialization. However, lower capabilities...

Sustainable Cathodic Performances of VS4 in Rechargeable Magnesium Batteries by Cobalt Substitution

“…The participation of V-3d and S-3p states in the valence and conduction band is in agreement with the literature; 43 however, a sharp band due to Co-3d states appeared below the conduction band. The 0.91 eV band gap of VS 4 , consistent with the literature, 44,45 widens and becomes 0.97 eV on Co incorporation. The DOS plots exhibit that VS 4 cathode electronic performance is not affected except for band gap widening.…”

“…Jankowski and Lastra explained that V–S bonds break at higher concentration of Mg ions and form a cluster of Mg–S inside the cathode, which results in capacity decreases and overall reduced performances of RMBS . A similar performance of reduced behavior of VS 4 was experimentally observed in our previous work . A stable long cyclic performance was reported due to tungsten (W)-doped VS 4 . , The enhanced performance along with expanded layers and sulfur vacancies was attributed to multielectron participation.…”

“…Still, 9% CoVS 4 demonstrated a capacity of 158 mAh g –1 at a current density of 500 mA g –1 with approximately 98% capacity retention at 1000 cycles and 60% capacity retention at 2000 cycles. The specific capacity can be improved by further optimization; e.g., a particle size of less than 500 nm has been achieved in this work, whereas we had achieved around 157 nm in our previous work . Particle size growth is directly proportional to microwave time; therefore, achieving a particle size less than 100 nm or nanosheet morphology is certainly possible and more beneficial toward achieving higher specific capacity.…”

Samarium-Doped Vanadium Dioxide Thin Films to Modulate the Thermochromic Properties for Energy-Saving Smart Windows

“…All density functional theory (DFT) calculations were performed in the Vienna Ab Initio Simulation Package (VASP) to explore the structural, electronic, and optical properties of pristine and Sm-doped VO 2 . The all-electron projector augmented wave (PAW) was employed for core electrons, and generalized gradient approximation (GGA) with the Perdew–Burke–Ernzerhof (PBE) exchange-correlation functional was employed to deal with valence electrons. − Hubbard U correction was adopted to accurately predict the relative stability, electron properties, and bandgap of VO 2 . , The U eff values of 3.4 eV for V-3 d and 9.5 eV for Sm-4 f were applied to treat on-site coulomb repulsion among electrons of partially filled orbitals. Regarding the experimental doping concentration, VO 2 (M 1 ) supercell structures of 2 × 2 × 3, 2 × 2 × 2, and 2 × 2 × 1 primitive unit cells were simulated to get 2.08, 3.12, and 6.25% Sm doping concentrations, respectively, by replacing one V atom with a Sm dopant in each supercell configuration.…”