Sulfur-Embedded FeS₂ as a High-Performance Cathode for Room Temperature All-Solid-State Lithium-Sulfur Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• All-solid-state lithium-sulfur batteries face challenges due to low sulfur cathode conductivity at room temperature.
• Developing stable and high-performance solid electrolytes and cathode materials is crucial for advancing battery technology.

Purpose of the Study:

• To develop room-temperature all-solid-state lithium-sulfur batteries with improved performance.
• To investigate the use of thin sulfur layer-embedded FeS2 (FeS2@S) microsphere composites as active cathode materials.

Main Methods:

• Fabrication of FeS2@S microsphere composites for cathode electrodes.
• Assembly of all-solid-state lithium-sulfur batteries utilizing FeS2@S and Li10GeP2S12 solid electrolyte.
• Electrochemical testing at room temperature with controlled cut-off voltages (1.5–2.8 V).

Main Results:

• The FeS2@S composite cathode enabled specific capacities of up to 1120.9 mA h g-1.
• Sulfur delivered normalized capacities ranging from 1645.5 to 363.6 mA h g-1 across various current densities (30–5000 mA g-1).
• The batteries maintained a normalized capacity of 430.7 mA h g-1 for sulfur at 1000 mA g-1 after 200 cycles.

Conclusions:

• The FeS2@S composite effectively mitigates volume changes during cycling, enhancing structural integrity.
• The developed all-solid-state lithium-sulfur batteries exhibit excellent rate capability and long-term cycling stability at room temperature.
• This approach offers a promising strategy for high-performance solid-state sulfur battery development.