Open AccessThe Role of Local Inhomogeneities on Dendrite Growth in LLZO-Based Solid Electrolytes
Author(s) -
Pallab Barai,
Anh T. Ngo,
Badri Narayanan,
Kenneth Higa,
Larry A. Curtiss,
Venkat Srinivasan
Publication year - 2020
Publication title -
journal of the electrochemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.258
H-Index - 271
eISSN - 1945-7111
pISSN - 0013-4651
DOI - 10.1149/1945-7111/ab9b08
Subject(s) - materials science , electrolyte , ceramic , microstructure , crystallite , grain boundary , composite material , dendrite (mathematics) , grain size , lithium (medication) , chemical physics , metallurgy , chemistry , medicine , geometry , mathematics , electrode , endocrinology
The majority of the ceramic solid electrolytes (LLZO, LATP) demonstrate polycrystalline grain/grain-boundary (G/GB) microstructure. Higher lithium (Li) concentration and lower mechanical stiffness result in current focusing at the GBs. Growth of Li dendrites through local inhomogeneities and subsequent short circuit of the cell is a major concern. Recent studies have revealed that bulk Li metal is a viscoplastic material that has low (∼0.3 MPa) and high (∼1.0 MPa) yield strength during deformation at smaller and larger rates of strain, respectively. It has been argued that during deposition at smaller current densities, due to its lower yield strength, Li metal should demonstrate plastic flow against stiff ceramic electrolytes, and Li dendrites will be prevented from penetrating through solid electrolytes. In this manuscript, a multiscale modeling framework has been developed for predicting properties of GBs and the bulk of ceramic electrolytes using atomistic calculations for input to mesoscale models. Using the parameters obtained from the atomistic simulations, the mesoscale model reveals that, given enough time, even at low charge rates, lithium dendrites can grow through the GBs of LLZO. The present multiscale model results also provide information regarding the dendrite growth velocity through LLZO.