Optimized Porous KTi₂(PO₄)₃@N-Doped Carbon Electrode for Enhanced Sodium/Potassium-Storage and Accelerated Activation...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Developing high-performance electrode materials is crucial for next-generation energy storage devices.
• Porous KTi2(PO4)3 (KTP) offers potential but requires enhanced conductivity and ion transport.
• Nitrogen-doped carbon coatings can improve electronic conductivity and ion interactions.

Purpose of the Study:

• To synthesize and characterize porous KTi2(PO4)3 nanoparticles coated with nitrogen-doped carbon (KTP@NC).
• To evaluate the electrochemical performance of KTP@NC as an electrode material for sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs).
• To elucidate the role of the nitrogen-doped carbon coating in enhancing electrochemical properties.

Main Methods:

• Solvothermal synthesis of porous KTi2(PO4)3 nanoparticles.
• Modification with polydopamine followed by carbonization to create a nitrogen-doped carbon layer.
• Electrochemical characterization including cyclic voltammetry, galvanostatic charge-discharge, and cycling stability tests.
• Material characterization using XRD, SEM, TEM, and Raman spectroscopy.

Main Results:

• The KTP@NC composite retained the porous structure with an interconnected nitrogen-doped carbon network.
• The nitrogen-doped carbon layer significantly improved electronic conductivity and ion adsorption.
• For SIBs, KTP@NC achieved a reversible capacity of 88.4 mA h g-1 at 30C with 97.3% capacity retention after 400 cycles.
• For PIBs, KTP@NC delivered a specific capacity of 98.9 mA h g-1 at 0.5C and maintained 92.9% capacity retention after 150 cycles.
• The material exhibited excellent cycle stability at elevated temperatures (50 °C).

Conclusions:

• The nitrogen-doped carbon coating effectively enhances the electrochemical performance of porous KTi2(PO4)3 for both SIBs and PIBs.
• Improved reaction kinetics and electronic conductivity are key factors contributing to the enhanced performance.
• KTP@NC is a promising electrode material for advanced sodium-ion and potassium-ion batteries.