Operando Monitoring of Chemo-Mechanical Stress Evolution in SiO/C Composite Anodes via Optical Frequency Domain...

Area of Science:

• Materials Science
• Electrochemistry
• Mechanical Engineering

Background:

• Lithium-ion battery performance relies heavily on anode material stability during charge/discharge cycles.
• The expansion and contraction of anode materials induce chemo-mechanical stress, impacting battery lifespan.
• Understanding stress evolution in advanced anode materials like silicon-carbon composites is critical.

Purpose of the Study:

• To investigate the chemo-mechanical stress evolution in silicon-carbon composite anode materials during lithium-ion battery cycling.
• To develop and apply a novel high-resolution technique for in-situ stress monitoring.
• To correlate stress changes with material morphology and battery performance.

Main Methods:

• Utilized a high spatial resolution phase-sensitive optical frequency domain reflectometry (φ-OFDR) technique.
• Embedded the fiber optic sensor directly into the anode of a lithium-ion battery.
• Monitored stress evolution with a spatial resolution of 1.5 mm under varying loading conditions.

Main Results:

• Successfully monitored chemo-mechanical stress evolution in real-time during battery cycling.
• Demonstrated the ability to infer material morphological changes from stress data.
• Established a correlation between stress patterns, material behavior, and battery capacity.

Conclusions:

• The developed φ-OFDR technique provides a powerful tool for in-situ chemo-mechanical stress analysis in battery anodes.
• This method offers a new approach for assessing lithium-ion battery performance and material degradation.
• Understanding stress evolution is key to designing more durable and efficient battery systems.