Li and other alkali metals (e.g., sodium and potassium) are very attractive electrode candidates for the next-generation rechargeable batteries that promise several times higher energy density at a lower cost. However, Li-dendrite formation severely limits the commercialization of Li-metal batteries; either because dendrite pieces lose electrical contact with the rest of the Li-electrode or because growing dendrites can penetrate the separator and lead to short circuits. The dendrite growth process can be strongly affected by a thin layer formed between the anode and the electrolyte, the so-called solid-electrolyte interphase (SEI) layer. Specifically, infinite volume change during the Li stripping/plating process results in the localized stress, deformation and eventually fractures in the SEI layer. Such cracks or defects in the SEI layer make the fresh Li-metal exposed to the electrolyte and thus serve as the “hot spot” for the nucleation of Li-dendrite growth. However, there is currently a lack of fundamental knowledge of when and where the dendrite formation starts, under what conditions it becomes dangerous and unstable, and what the relationship between the Li-dendrite and the SEI is. Our research aims to develop a mechanistic computational model to address these critical questions that potentially establish the scientific basis for developing and designing nanostructures or microarchitectures to overcome the Li-dendrite failure. Two examples will be highlighted: (i) well-spaced nanochannels with fast Li transport to achieve the uniform Li concentration, and (ii) solid electrolytes with manipulated microstructures to confine the Li-dendrite mechanically.

Accelerated computational design of dendrite-free Li-metal batteries

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.