Direct Measurements of Dendrite-Induced Stresses in Ceramic Electrolytes via Photoelasticity

The measurement of stress fields around lithium metal protrusions in solid electrolytes in operating conditions is critical for the design of next-generation, dendrite-resistant solid electrolytes. However, such stress measurements entail inherent experimental difficulties associated with acquiring accurate data at small scales in thin ceramic electrolytes.<br/><br/>By employing the principle of photoelasticity combined with electrochemical cycling in a plan- view cell the aforementioned challenges are bypassed, allowing not only to track the stress field as the dendrite events progress, but also to obtain full field stress information on a propagating dendrite in semi-transparent LLZTO electrolyte. This new experimental methodology allows for 1. quantification of the stress fields around the dendrite tip and 2. clear verification that the stress field observed at the experiments can be explained by linear elastic fracture mechanics.