A high-power lithium-sulfur battery combining a catholyte and a composite cathode

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Lithium batteries are crucial for energy storage.
• Sulfur-based electrodes offer high theoretical capacity.
• Polysulfide conversion reactions present challenges and opportunities in lithium-sulfur batteries.

Purpose of the Study:

• To investigate the performance of lithium batteries employing soluble polysulfide conversion reactions.
• To optimize sulfur-based electrodes for enhanced energy and power density.
• To evaluate the long-term cycling stability of these advanced lithium batteries.

Main Methods:

• Utilizing soluble polysulfide conversion reactions.
• Fabricating sulfur-based electrodes with controlled sulfur content (4.5–6.5 mg cm^-2).
• Conducting electrochemical performance testing, including energy density, power density, and cycling stability.

Main Results:

• Exceptional energy density achieved, ranging from 700 W h kg_S^-1 at 0.1C to 100 W h kg_S^-1 at 50C.
• High power density demonstrated, from 100 W kg_S^-1 at 0.1C to 35 kW kg_S^-1 at 50C.
• Sustained performance over 500 cycles, indicating excellent long-term stability.

Conclusions:

• The conversion reaction of soluble polysulfides with sulfur electrodes significantly enhances lithium battery performance.
• Optimized sulfur content in electrodes leads to superior energy and power characteristics.
• These findings pave the way for developing high-performance, long-lasting lithium-sulfur batteries.