Synergistic Structural and Defect Engineering in MoS₂ Featuring Ultra-Expanded Interlayers for Fast-Chargeable and...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Molybdenum disulfide (MoS₂) shows potential for sodium-ion batteries (SIBs) due to high capacity.
• Challenges include sluggish kinetics, volume changes, and unstable solid electrolyte interphase (SEI).

Purpose of the Study:

• To mitigate MoS₂ anode limitations using concurrent selenium doping and carbon intercalation.
• To design a synergistic MoS₂ anode for improved structural flexibility and electrochemical performance.

Main Methods:

• Theoretical analysis of selenium doping and carbon intercalation effects.
• Experimental synthesis of hollow carbon sphere-confined, carbon-intercalated, and selenium-doped MoS₂ (MoSSe@HCS).
• Characterization of structural, electronic, and electrochemical properties.

Main Results:

• MoSSe@HCS achieved an expanded interlayer spacing of 1.24 nm with carbon encapsulation.
• Demonstrated high capacity (441.5 mAh g⁻¹ at 0.1 A g⁻¹), excellent rate capability (121.9 mAh g⁻¹ at 30 A g⁻¹), and superior cyclability (87.3% retention after 1000 cycles).
• Full cells showed high capacity retention and over 2500 cycles, indicating commercial viability.

Conclusions:

• Concurrent selenium doping and carbon intercalation effectively address MoS₂ anode challenges.
• The MoSSe@HCS anode design offers a promising pathway for high-performance SIBs.
• This work provides a theory-guided approach for developing advanced battery materials.