Investigation of Volume Change and Interfacial Contact Degradation Mechanism of Solid State Battery Conversion Cathodes

Sulfur-based materials are among the most widely investigated compounds as conversion-type cathode-active materials for batteries. While their use in conventional batteries is challenging due to detrimental interactions with liquid electrolyte, solid-state batteries (SSBs) offer a potential solution due to improved stability. However, conversion cathodes undergo huge volume changes during charging and discharging reactions. This volume expansion and contraction has severe effects on SSBs, such as cracks within the cathode. Our group has previously shown that operando synchrotron X-ray micro-CT can be used to reveal the degradation mechanisms of different SSB electrode materials, such as lithium metal and silicon electrodes. The goal of the proposed beamtime allocation is to observe chemo-mechanical degradation of conversion-type cathodes in SSBs through electrode and interfacial fracture and relate this to their changing microstructures during electrochemical cycling.