Frozen slab method mediated sulfur-affinitive single-atom catalysts for efficient reversible sodium storage.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• MoS2-based sodium-ion batteries face challenges with irreversible reactions.
• Conventional single-atom catalysts (C-SAMs) often mispredict Na2S adsorption due to neglecting Na-N bonds and structural deformation.

Purpose of the Study:

• To develop a new method for evaluating C-SAMs' influence on Na2S adsorption.
• To classify C-SAMs based on their affinities for Na and S.
• To enhance the reversibility of MoS2-based sodium-ion batteries.

Main Methods:

• Introduced the frozen slab method to assess C-SAM affinities for Na and S.
• Classified C-SAMs into S-affinitive, amphiphilic, and Na-affinitive categories.
• Performed theoretical calculations and experimental validation.

Main Results:

• S-affinitive C-SAMs strongly adsorb sulfur, weakening Na-S bonds and facilitating Na2S decomposition.
• This reduces the energy barrier for Na2S decomposition, improving conversion reaction reversibility.
• Experimental validation showed S-affinitive C-SAV accelerated Na+ storage in MoS2.

Conclusions:

• S-affinitive C-SAMs are effective in enhancing the reversibility of MoS2-based sodium-ion batteries.
• The developed method provides a new approach for designing advanced catalysts.
• MoS2/C-SAV electrodes demonstrated excellent long-term stability and high capacity retention.