The Insights of Lithium Metal Plating/Stripping in Porous Hosts: Progress and Perspectives

Lithium (Li) metal is strongly regarded as a promising anode for next-generation secondary batteries. However, the nonuniform plating/stripping and volume fluctuation of the Li metal anode give rise to low Coulombic efficiency and short lifespan of Li metal batteries, which hinder practical applications of the Li metal anode. A composite Li metal anode that employs a stable porous host has been proposed as a promising strategy to regulate the behaviors of Li plating/stripping and relieve volume fluctuation. In a porous host, the basic building block is a pore. The pore structure affects the distribution of electric and Li-ion concentration fields during Li plating/stripping, thus regulating Li plating/stripping and the lifespan of the composite Li metal anode. Therefore, herein, the recent progress in investigating the behavior of Li plating/stripping in a pore based on liquid electrolytes is summarized from the aspects of pore diameter, depth, and tortuosity. Furthermore, the perspectives of rational design of the pore structure for a composite Li metal anode are presented to promote the development of Li metal anodes.