Disordered Rock-Salt Type Li₂TiS₃ as Novel Cathode for LIBs: A Computational Point of View

Area of Science:

• Materials Science
• Computational Chemistry
• Electrochemistry

Background:

• Development of high-energy cathode materials for lithium-ion batteries (LIBs) is crucial for technological progress.
• Critical raw materials like cobalt and nickel present supply chain challenges.
• Lithium-rich sulfides, particularly disordered cubic Li2TiS3, show promise for LIBs and all-solid-state batteries.

Purpose of the Study:

• To computationally determine accurate structural, electronic, and spectroscopic properties of disordered cubic Li2TiS3.
• To establish a robust predictive scheme for lithium-rich sulfide materials.
• To investigate the correlation between material structure and its Raman fingerprint.

Main Methods:

• Density Functional Theory (DFT) hybrid Hamiltonian calculations.
• Localized basis functions and the periodic CRYSTAL code.
• Simulation of Raman spectra, XRD patterns, electronic band structures, and density of states.

Main Results:

• Accurate structural, electronic, and spectroscopic properties were predicted for Li2TiS3 and related compounds.
• A consistent predictive scheme was developed using benchmark systems like Li2S, TiS2, TiS3, LiTiS2, and monoclinic Li2TiS3.
• Disordered rock-salt type Li2TiS3 structures were derived and characterized, establishing a structure-Raman fingerprint correlation.

Conclusions:

• The computational approach provides accurate predictions for lithium-rich sulfide cathode materials.
• Disordered cubic Li2TiS3 exhibits promising properties for next-generation LIBs.
• The established structure-Raman correlation aids in material identification and characterization.