An Enhanced "Trapping-Conversion" Function Enables Ultrastable Potassium Ion Storage.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Metal chalcogenides (MCs) are promising for potassium ion battery (KIB) anodes.
• Sluggish kinetics and shuttle effects limit MC performance in KIBs.
• Developing advanced anode materials is crucial for efficient KIBs.

Purpose of the Study:

• To design and synthesize a P-doped PbTe/MXene superstructure for enhanced KIB anode performance.
• To investigate the impact of P-doping on the electrochemical properties of PbTe/MXene.
• To address the limitations of sluggish redox kinetics and shuttle effects in KIB anodes.

Main Methods:

• Hydrothermal reaction to decorate PbTe on MXene.
• Bifunctional phosphorus doping of both PbTe and MXene lattices.
• Electrochemical characterization of the P-PbTe/MXene anode in KIBs.

Main Results:

• The P-PbTe/MXene anode demonstrated high reversible capacity (289.1 mAh g^-1 at 0.2 A g^-1 after 200 cycles).
• Exceptional rate performance was achieved (151.3 mAh g^-1 at 20 A g^-1).
• Ultrastable cyclability was observed (180.1 mAh g^-1 at 2.0 A g^-1 after 2000 cycles) with high energy density and bending stability in full cells.

Conclusions:

• The P-PbTe/MXene superstructure effectively enhances KIB anode performance by improving kinetics and suppressing the shuttle effect.
• The P-doping strategy offers a viable route for developing high-performance KIB anode materials.
• This work contributes to the advancement of next-generation potassium-based energy storage systems.