Stereochemically Active Lone Pairs Promoted High Rate Potassium-Ion Storage in Bismuth Sulfide

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Bismuth sulfide (Bi₂S₃) is a potential anode material for potassium-ion batteries due to its high capacity and low cost.
• However, Bi₂S₃ suffers from poor cycling stability and rate performance caused by significant volume expansion and structural degradation during cycling.

Purpose of the Study:

• To develop a novel strategy combining stereochemically active lone pairs (SCALP)-oriented modulation with structural engineering to enhance Bi₂S₃ anode performance.
• To synthesize and characterize hollow carbon sphere-supported Bi₂S₃ (HCS@Bi₂S₃) for improved potassium-ion battery applications.

Main Methods:

• Density functional theory (DFT) calculations were used to predict the effect of lattice distortion on SCALP behavior.
• Hollow carbon sphere-supported bismuth sulfide (HCS@Bi₂S₃) was synthesized by controlling the sulfidation time.
• Electrochemical performance was evaluated using coin cells and a full cell with a perylenetetracarboxylic dianhydride cathode.

Main Results:

• The HCS@Bi₂S₃-3 composite exhibited a high reversible capacity of 471.5 mAh g⁻¹ at 200 mA g⁻¹.
• Excellent long-term cycling stability was achieved, retaining 147.3 mAh g⁻¹ after 1000 cycles at 10 A g⁻¹.
• Superior rate capability was demonstrated, with a capacity of 128.4 mAh g⁻¹ at 12 A g⁻¹.

Conclusions:

• The integrated SCALP-oriented strategy and HCS structural engineering effectively improved the electrochemical performance of Bi₂S₃ anodes.
• HCS@Bi₂S₃ demonstrates significant potential as a high-performance anode material for fast and stable potassium storage.
• This work offers a new pathway for developing advanced metal chalcogenide-based anodes for potassium-ion batteries.