Atomistic insights into the morphology of deposited Li

Abstract

Rechargeable lithium (Li) metal batteries (RLMBs) have attracted global research interest over the past few decades. However, their practical deployment has encountered the uncontrollable growth of Li dendrites and low coulombic efficiency (CE), which are intimately related to the morphology of deposited Li. Nevertheless, the current understanding of deposited Li metal at the atomistic level is not comprehensive enough. In this Perspective, we attempt to establish the relationship between the morphology of the deposited Li and reversibility of Li plating/stripping. To this end, we begin with a simple introduction to underscore the importance of RLMBs in current electrochemical energy storage and conversion systems. Then, we revisit the plating process of Li metal. Contextually, we highlight the importance of the solid electrolyte interphase (SEI) film with respect to CE, the properties of SEI film, and the transport mechanism of Li⁺ inside the SEI film. Subsequently, we classify and deeply discuss the factors affecting the morphology of deposited Li. Afterwards, we selectively summarize the advanced characterization techniques for detecting the morphology of deposited Li at the atomic scale. Finally, we provide personal insights and perspectives on the future development of RLMBs.