Interfacial Electronic Properties Dictate Li Dendrite Growth in Solid Electrolytes

By H. Tian, Zhe Liu, Yanzhou Ji, Long-qing Chen, Yue Qi. Chemistry of Materials, 2019

248 citations recorded by the source corpus.

The experimental observation of Li dendrite growth inside mechanically hard solid electrolytes (SEs) raised an important question: can hard SEs mechanically stop Li-dendrite growth? Here, we report a multiscale model coupling density functional theory calculations with the phase-field method to address the question. In particular, we investigate the roles of internal defects, such as pores and crack surfaces, inside a number of SEs including cubic Li7La3Zr2O12 (c-LLZO), β-Li3PS4, Li1.17Al0.17Ti1.83(PO4)3 (LATP), and Li2PO2N. It is shown that LLZO surfaces have a much smaller band gap than the corresponding bulk and thus could trap significant excess electrons, whereas the other three systems do not exhibit significant differences in the surface and bulk band gaps. A fully coupled phase-field model was then developed to further examine the impact of excess surface electrons on the Li dendrite growth morphology in polycrystalline LLZO. This model successfully explained the experimentally observed dendrite i...

Subfields: Automotive Engineering, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/d3d3cd8562db7b853b3833145866bf77ae6a254f