High-Performance Lithiated SiO Anode Obtained by a Controllable and Efficient Prelithiation Strategy.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Silicon anodes offer high theoretical capacity for Li-ion batteries but suffer from poor initial Coulombic efficiency (ICE) due to volume expansion and SEI instability.
• Prelithiation is a key strategy to mitigate Li+ loss during the first lithiation cycle.

Purpose of the Study:

• To develop a controllable and efficient prelithiation strategy for silicon oxide (SiOₓ) anodes.
• To improve the initial Coulombic efficiency (ICE) and cycling stability of SiOₓ-based lithium-ion batteries.

Main Methods:

• A novel prelithiation strategy was employed to prepare a homogeneous lithiated SiOₓ anode.
• Improved Li+ diffusion in SiOₓ facilitated efficient bulk lithiation.
• In situ SEI formation during prelithiation minimized irreversible capacity loss.

Main Results:

• The prelithiation strategy resulted in homogeneous and efficient lithiation of SiOₓ.
• Initial Coulombic efficiency (ICE) improved from 79% to 89% in half-cells and 68% to 87% in full cells.
• The lithiated SiOₓ anode demonstrated stable cycling for 200 cycles in NCM622//SiOₓ coin full cells.

Conclusions:

• The developed prelithiation method offers a viable approach to enhance the performance of SiOₓ anodes.
• This strategy significantly improves ICE and cycling stability, paving the way for advanced high-energy-density Li-ion batteries.