Pseudohexagonal Nb₂O₅ Anodes for Fast-Charging Potassium-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• High-rate batteries are crucial for future energy storage, but post-lithium-ion chemistries lag behind lithium-ion advancements.
• Potassium-ion batteries (KIBs) offer a promising alternative to lithium-ion batteries but require efficient anode materials for high-rate performance.

Purpose of the Study:

• To investigate the potential of pseudohexagonal niobium pentoxide (TT-Nb2O5) as an anode material for potassium-ion batteries.
• To enhance the electrochemical performance of TT-Nb2O5 by compositing it with a conductive carbon framework for high-rate KIB applications.

Main Methods:

• A one-step hydrothermal method was employed to synthesize TT-Nb2O5 composited with multiwalled carbon nanotubes (Nb2O5@CNT) using glucose-derived carbon.
• The resulting needle-like structures were characterized for their conductivity and porosity.
• Electrochemical performance, including specific capacity and rate capability, was evaluated in potassium-ion battery configurations.

Main Results:

• The Nb2O5@CNT composite exhibited a high specific capacity of 179 mAh g−1 at approximately 0.3C.
• Excellent rate performance was demonstrated, with a capacity of 72 mAh g−1 maintained at approximately 15C.
• The material showed good cycling stability, indicating a promising lifetime for KIB applications.

Conclusions:

• This study reports the first investigation of TT-Nb2O5 as an anode material for KIBs, demonstrating its viability.
• The developed Nb2O5@CNT composite offers a scalable route for producing high-performance KIB anode materials.
• The findings contribute to the advancement of fast-charging potassium-ion batteries for future energy storage solutions.