TiO₂-Nanocoated Black Phosphorus Electrodes with Improved Electrochemical Performance

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Black phosphorus (BP) is a high-energy-density material for lithium-ion batteries.
• Volumetric expansion during lithiation causes capacity fading in BP electrodes.
• Stable and conductive electrode networks are crucial for battery performance.

Purpose of the Study:

• To enhance the stability and cycling performance of black phosphorus electrodes.
• To mitigate capacity fading caused by volumetric expansion in BP.
• To improve the overall efficiency and rate capability of lithium-ion batteries utilizing BP.

Main Methods:

• Composite electrodes were prepared using microsized BP particles with carbon nanotubes and KetjenBlack.
• An ultrathin TiO2 nanocoating was applied via electron-beam evaporation.
• The formation of a Li xTi yOz passivation layer was analyzed.

Main Results:

• The TiO2 nanocoating effectively protected BP particles from direct electrolyte contact.
• A Li xTi yOz passivation layer was formed, suppressing irreversible solid electrolyte interphase growth.
• Improved Coulombic efficiency, superior cycling stability, and enhanced rate performance were achieved.

Conclusions:

• TiO2 nanocoating is a viable strategy to stabilize black phosphorus electrodes.
• The passivation layer significantly improves the electrochemical performance of BP-based lithium-ion batteries.
• This approach offers a pathway for developing high-performance energy storage devices.