(Invited) Manipulation of Structure and Morphology of Solid-Electrolyte Interphase Layer for High-Performance Li Metal Batteries

Abstract

Lithium metal batteries are promising high-energy storage devices due to a high theoretical capacity of lithium (Li) anode. It is challenging to achieve Li anodes with high Coulombic efficiency (CE) due to poor stability of solid-electrolyte interphase (SEI) associated with excessive SEI accumulation and exacerbation of Li dendrite growth, leading to poor capacity retention and short cycling life of Li metal batteries. In this talk, I will present strategies to reinforce the SEI with desired properties including good tolerance to the Li interface change and efficient surface passivation against electrolyte penetration. The approach works via either introducing multiple functional components bonded to the Li surface into the SEI or depositing flexible organic/inorganic hybrid coating layer. This self-forming of the reinforced SEI can be triggered once fresh Li is deposited at the interface, thus realizing a lasting formation of the stable SEI. The as-formed durable SEI layer can suppress dendritic Li growth, enhance Li plating/stripping CE, and in turn, enable Li metal batteries with long cycling life and excellent capacity retention. We demonstrate the reinforced SEI can improve Li metal efficiency in a carbonate-based electrolyte for Li-metal oxide batteries and a ether-based electrolyte for Li-sulfur batteries. This study provides a promising route to address the issues associated with Li metal anodes and promote the development of high-energy rechargeable Li metal batteries.