Operando Spatial and Temporal Tracking of Axial Stresses and Interfaces in Solid-state Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Solid-state batteries offer advantages over liquid electrolyte batteries but suffer from ionic conductivity loss.
• This loss is primarily caused by mechanical stresses from volume changes during battery cycling, leading to component delamination.
• Understanding the real-time stress evolution within solid-state batteries is crucial for their development.

Purpose of the Study:

• To investigate the spatio-temporal distribution of mechanical stresses during solid-state battery operation.
• To correlate these stresses with observed degradation phenomena and component volume changes.
• To establish a methodology for real-time monitoring of chemo-mechanical processes in solid-state batteries.

Main Methods:

• Utilized operando scanning high-energy X-ray diffraction (XRD) to measure cross-sectional axial stresses.
• Achieved a spatial resolution of 10 µm for detailed stress mapping.
• Monitored unit cell volume changes in the cathode and degradation near the lithium anode.

Main Results:

• Observed a non-monotonous evolution of stress distribution over time during battery cycling.
• Identified degradation of the solid-state electrolyte adjacent to the lithium anode.
• Tracked periodic changes in the cathode's unit cell volume, correlating with cycling.

Conclusions:

• The developed operando XRD technique provides real-time insights into chemo-mechanically induced stresses and interface evolution.
• This methodology is valuable for understanding degradation mechanisms in solid-state batteries.
• The findings offer a platform for optimizing solid-state battery design and performance.