Engineering High-Performance SiO_x Anode Materials with a Titanium Oxynitride Coating for Lithium-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Micron-sized silicon oxide (SiO) is a promising anode material for lithium-ion batteries due to its high capacity and low cost.
• However, SiO anodes face challenges including significant volume expansion during cycling and poor electrical conductivity, leading to capacity fading and structural degradation.

Purpose of the Study:

• To enhance the electrochemical performance of silicon oxide anodes by suppressing volume expansion and improving conductivity.
• To develop a facile surface modification technique for SiO anodes using titanium oxynitride (TiON) coatings.

Main Methods:

• Fabrication of SiO anode materials coated with TiO0.6N0.4 layers using a solvothermal and thermal reduction technique.
• Characterization of the composite material's structure, morphology, and electrochemical properties.

Main Results:

• Homogeneous dispersion of TiO0.6N0.4 layers on SiO particles, forming intimate contact.
• The TiON coating effectively enhanced the conductivity and suppressed the volume expansion of the SiO anode.
• The modified SiO-TiON-200 composite achieved a high reversible capacity of 854 mAh g⁻¹ at 0.5 A g⁻¹ after 250 cycles.

Conclusions:

• Surface modification with TiO0.6N0.4 layers is an effective strategy to improve the performance of SiO anodes for lithium-ion batteries.
• The developed technique offers a potential pathway for enhancing other low-conductivity, high-volume-expansion anode materials.