Single-Atom Yttrium Engineering Janus Electrode for Rechargeable Na-S Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Rechargeable sodium-sulfur (Na-S) batteries offer high energy density and low cost but suffer from polysulfide shuttle and sodium dendrite issues.
• Sluggish redox kinetics of sulfur species hinder efficient electrochemical conversion in Na-S batteries.

Purpose of the Study:

• To address the limitations of Na-S batteries by designing a novel host material for sodium anodes and sulfur cathodes.
• To investigate the potential of yttrium (Y)-N4 single-atom sites as Janus catalysts for improved Na-S battery performance.

Main Methods:

• Utilized a metal-organic framework (MOF) to synthesize a nitrogen-doped carbon host incorporating yttrium single atoms (Y SAs/NC).
• Characterized the Y SAs/NC material for its 'Janus' properties, specifically sodiophilicity and sulfiphilicity.
• Assembled and tested Na-S full cells using Y SAs/NC as the electrode host material.

Main Results:

• The Y SAs/NC material demonstrated excellent electrochemical performance in Na-S full cells.
• Achieved a high capacity of 822 mAh g⁻¹ with remarkable cyclability, retaining 97.5% capacity over 1000 cycles at 5 A g⁻¹.
• Proof-of-concept 3D printed batteries and pouch cells validated the practical applicability of the developed Na-S technology.

Conclusions:

• The Y single-atom sites incorporated into a nitrogen-doped carbon host effectively mitigate polysulfide shuttle and sodium dendrite issues.
• The developed Y SAs/NC material shows significant promise for advancing high-performance and durable Na-S batteries for energy storage applications.