High-power lithium-selenium batteries enabled by atomic cobalt electrocatalyst in hollow carbon cathode

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-selenium (Li-Se) batteries offer high potential due to selenium's conductivity and capacity.
• Challenges include low selenium reactivity, volume changes, and polyselenide shuttle effect, hindering practical application.
• Single atom catalysts (SACs) show promise for energy storage due to unique properties and high atom utilization.

Purpose of the Study:

• To develop an effective catalyst for improving lithium-selenium battery performance.
• To address the limitations of low reactivity and polyselenide shuttle in Li-Se batteries.
• To synthesize and characterize cobalt single atoms supported on nitrogen-doped hollow porous carbon (CoSA-HC) for selenium cathodes.

Main Methods:

• Facile synthesis of cobalt single atoms/nitrogen-doped hollow porous carbon (CoSA-HC).
• Fabrication of selenium-carbon (Se@CoSA-HC) composite cathodes.
• Electrochemical testing including discharge capacity, rate capability, cycling stability, and Coulombic efficiency.

Main Results:

• CoSA-HC effectively activates selenium reactivity and immobilizes selenium and polyselenides.
• The Se@CoSA-HC cathodes exhibit high discharge capacity and superior rate capability.
• Excellent cycling stability with a Coulombic efficiency of approximately 100% was achieved.

Conclusions:

• Cobalt single atoms on nitrogen-doped hollow porous carbon are effective for enhancing Li-Se battery performance.
• The developed cathode material mitigates key issues like polyselenide shuttle and low reactivity.
• This approach offers a promising pathway for developing long-life, high-power lithium-selenium batteries.