Polyselenide Anchoring Using Transition-Metal Disulfides for Enhanced Lithium-Selenium Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• Selenium is a promising cathode material for lithium batteries, offering an alternative to lithium-sulfur systems.
• Improving the cycle stability of lithium-selenium batteries requires addressing the dissolution of intermediate species.

Purpose of the Study:

• To investigate transition-metal disulfides as anchoring materials for lithium batteries.
• To understand the mechanism behind preventing active material loss using computational methods.

Main Methods:

• Density functional theory (DFT) calculations were employed to study various transition-metal disulfides.
• Crystal-field theory was used to analyze the governing interactions and anchoring strengths.

Main Results:

• Group 5 and 4 transition-metal disulfides (VS2, NbS2, TaS2, TiS2, ZrS2, HfS2) demonstrated superior anchoring capabilities compared to group 6 disulfides (CrS2, MoS2, WS2).
• Charge transfer, explained by crystal-field theory, was identified as the key interaction determining anchoring strength.

Conclusions:

• Transition-metal disulfides are effective inorganic anchoring materials for lithium-selenium and lithium-sulfur batteries.
• The findings provide insights for designing advanced anchoring materials to enhance battery performance and stability.