Novel Ultra-Stable 2D SbBi Alloy Structure with Precise Regulation Ratio Enables Long-Stable Potassium/Lithium-Ion...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Two-dimensional (2D) antimony (Sb) and bismuth (Bi) have limitations in cycling stability and capacity for high-performance potassium-ion batteries (PIBs) and lithium-ion batteries (LIBs).
• Developing binary alloys that combine the high capacity of Sb with the stability of Bi is crucial for advanced energy storage.

Purpose of the Study:

• To fabricate novel 2D binary SbBi alloys with tunable atomic ratios.
• To evaluate the electrochemical performance of these alloys as anodes in PIBs and LIBs.
• To elucidate the storage mechanisms and the origin of enhanced performance.

Main Methods:

• One-step co-replacement method for synthesizing 2D SbBi alloys.
• Electrochemical testing (cycling stability, capacity retention) in PIBs and LIBs.
• Kinetic analysis, in-situ/ex-situ characterization, and theoretical calculations to study storage mechanisms.

Main Results:

• Successfully fabricated a series of 2D SbBi alloys.
• The 2D-Sb_0.6Bi_0.4 anode demonstrated high capacity (381.1 mAh g^-1 after 500 cycles at 0.2 A g^-1 with 87.8% retention) and ultra-long cycling stability (1000 cycles at 1.0 A g^-1 with 0.037% decay per cycle) in PIBs.
• Superior performance in LIBs was also observed, attributed to structural stability and synergistic effects.

Conclusions:

• The 2D-Sb_0.6Bi_0.4 alloy offers a promising anode material for high-performance PIBs and LIBs.
• The synergistic interaction in the 2D binary alloy structure alleviates volume expansion and enhances ion diffusion.
• This work presents a scalable strategy for designing 2D binary/ternary alloys for rechargeable batteries.