Metallic Li is the ultimate anode for next-generation batteries due to its highest theoretical capacity (3860 mAh g<sup>−1</sup>) and lowest potential (−3.04 V versus standard hydrogen electrode) among all the candidate materials. However, the practical applications of Li metal anode have been severely hindered by the problems of poor cycle life and serious safety concerns, which originated from its high reactivity with organic liquid electrolytes and uneven deposition behavior.<br/>In this talk, I will discuss the failure mechanisms of Li metal, especially the key role of infinite relative volume change on the electrode and interface stability. Upon the understandings, a series of rational “stable host” designs for constructing three-dimensional (3D) Li metal composites have been developed, which demonstrate significantly improved stability and electrochemical performance.<br/>In the second part, I will discuss how the physiochemical properties of the solid-electrolyte interphase (SEI), dictated by electrolyte composition, affect the electrochemical behavior of metallic Li. A special electrolyte additive has been discovered to enable high efficiency Li metal cycling in carbonate-based electrolytes, with a solubility-mediated sustained-release methodology introduced to overcome its solubility barrier. Moreover, the mechanism behind the improved performance has been studied based on the structure, ion-transport properties, and charge transfer kinetics of the modified interfacial environment using advanced characterization techniques.

Understanding and redesigning metallic lithium for next-generation batteries

2019 Fall National Meeting

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