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Item type:Publication, Access status: with files , MnTiO₃ as a carbon-free cathode for rechargeable Li–O₂ batteries(Royal Society of Chemistry (RSC), 2025-01-17); ; ; ; Li-O2 batteries (LOBs) are next-generation energy storage systems. However, their main challenges are the sluggish kinetics of oxygen reduction and evolution reactions (ORR/OER) and high charge overpotentials due to the formation of discharge product (Li2O2). To address this challenge, developing a catalyst with a unique structure and exceptional catalytic properties is crucial to enhancing the reversible cycling performance of LOBs, particularly under high current density conditions. Herein, the transition metal-based perovskite MnTiO3 was examined as a carbon-free cathode catalyst using density functional theory (DFT) calculations and experimental techniques. The intrinsic advantages of MnTiO3 stem from the coexistence of Mn and Ti energy levels near the Fermi level, as revealed by our density of states (DOS) analysis. This electronic structure facilitates ORR/OER, thus endowing MnTiO3 with a bifunctional role in promoting battery performance. Our DFT-based investigation elucidates the surface stability and catalytic properties of MnTiO3. Furthermore, Energy Dispersive Spectroscopy (EDS) and X-ray diffraction (XRD) confirm that the electrochemical reaction on MnTiO3 follows a two-electron pathway. Our findings reveal that a LOB with MnTiO3 exhibits a total overpotential of 1.18 V and 1.55 V using DFT and electrochemical measurements, respectively. High current densities up to 1 A g−1 also highlight its potential as a cathode catalyst for LOBs.Publicationtype: Journal Article22 25 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Sulfur-doped Li₁.₃Al₀.₃Ti₁.₇(PO₄)₃ as a solid electrolyte for all-solid-state batteries: First-principles calculations(2023-09-20); ; ; ; Cetinkaya, TuğrulSolid electrolytes are crucial in obtaining high safety standards and high energy densities in all-solid-state batteries (ASSBs). For ASSBs, it is essential to design solid electrolytes with high ionic conductivity. Herein, a density functional theory (DFT) study has been conducted to investigate the impact of substitutional sulfur doping into Li₁.₃Al₀.₃Ti₁.₇(PO₄)₃ (LATP) solid electrolyte which has a sodium superionic conductor (NaSICON) type crystal structure. A comprehensive study of the effect of sulfur doping on structural stability, Li-ion migration path, and electronic properties was carried out. DFT calculations indicate that sulfur doping locally improves the Li-ion migration kinetics which is accompanied by increased polyhedral volumes in the diffusion path. Moreover, experimental and computational studies were carried out on the electronic state of bare and sulfur-doped LATP. Band gap measurements performed by UV–Vis absorption analysis revealed that sulfur doping decreased the band gap from 2.35 eV to 2.10 eV in alignment with the theoretical calculations in which 1.83 eV was obtained in the most stable sulfur-doped configuration. Compared with bare-LATP, it has been validated that S@LATP has better ionic conductivity with reducing activation energy barrier as a solid electrolyte for all-solid-state batteries.Publicationtype: Journal Article130