The influence of stress-dependent overpotential on dendrite growth in all-solid-state battery with cracks

Abstract

Dendrite growth is one of the main challenges in maintaining the service life of all-solid-state lithium-ion batteries. Mechanical stress has been reported to significantly affect dendrite growth. In this study, to explain the effect of mechanical stress on electrochemical reactions in all-solid-state batteries, a modified phase-field model for dendrite growth is proposed by considering the stress-dependent overpotential. Dendrite growth under different mechanical loadings in an all-solid-state battery is investigated using the proposed model. Consistent with previous experimental results, the current result shows that compressive stress inhibits dendrite growth. Considering the stress concentration at the tips of processing-induced microcracks, the effects of the number and distribution of microcracks on dendrite growth are investigated. The results show that the stress-concentration field induced at the tips of cracks or voids can change the morphology of dendrites and decrease their growth rates. This study provides a new perspective for explaining Li dendrite growth under mechanical stress and offers inspiration for prolonging the service life of all-solid-state batteries based on defect and stress regulation, which may be further realized in experiments by filling solid electrolytes with different types of nanofillers.