SUMMARY

Lithium-ion batteries (LIBs) are being widely used in various applications. However, the growing market needs have imposed an increasing demand for a new generation of energy storage solutions with improved safety, high energy and power density, and environmental sustainability. To meet this end, a new design of LIBs, namely solid-state LIBs (SS-LIBs), has been under active investigation. Nevertheless, the commercialization of SS-LIBs is hindered by the coupled chemo-mechanical degradation of battery materials during cycling. To obtain a thorough understanding of these coupled degradation mechanisms, an in situ characterization platform using optical imaging, mechanical testing, and electrochemical impedance spectroscopy (EIS) measurements is designed to allow real-time observation of the chemical and mechanical evolutions of battery materials during cycling. This in situ platform has been used alongside with ex situ nanoindentation characterization to investigate the mechanical behavior of metallic lithium (Li) and the chemomechanical stability of sulfide SEs against Li anode. In this study, we will employ this platform to unravel the Li-dendrite induced fracture behavior of oxide SE materials. The results obtained from this work will provide in-depth insights into the mechanisms of performance degradation of SS-LIBs.