One-step microwave synthesized core-shell structured selenium@carbon spheres as cathode materials for rechargeable...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Lithium-selenium (Li-Se) batteries offer high theoretical energy density but suffer from the polysulfide shuttle effect.
• This effect leads to capacity decay and poor cycle life in Li-Se cells.

Purpose of the Study:

• To develop a stable cathode material for advanced lithium-selenium batteries.
• To mitigate the shuttle effect and improve long-term cycling performance.

Main Methods:

• A facile one-step microwave synthesis was employed to create selenium@carbon (Se@C) core-shell composite materials.
• Morphological analysis was conducted on the cathode materials after various charge-discharge cycles.

Main Results:

• Uniform carbon shells were successfully coated onto selenium spheres, forming a core-shell structure.
• The carbon shells effectively confined the selenium cores, minimizing the shuttle effect.
• The structural integrity of the Se@C composite was maintained throughout 100 cycles, demonstrating excellent stability.

Conclusions:

• The developed Se@C composite material is a promising cathode for high-performance and long-lasting lithium-selenium batteries.
• The core-shell architecture is crucial for suppressing polysulfide dissolution and ensuring structural stability.