Design of Self-Wetting Interface between Garnet Solid Electrolyte and Lithium Metal Electrode

Abstract

Solid-state lithium metal batteries have emerged as promising energy storage systems due to large energy storage density and low-risk safety hazard.However, high-interface resistance between the garnet-based electrolyte and Li metal anode is one of the major challenges for all-solid-state batteries.Herein, a straightforward modification method is reported, rather than relying on hot pressing under an inert atmosphere or high-cost fabrication techniques to produce metastable nanocoating on garnet electrolyte surface.Fresh Li metal/cobalt-modified solid-state electrolyte/Li metal batteries are placed at room temperature for 48 hours under a tiny pressure of 1 MPa, however the interfacial resistance between the garnet and Li metal reduces from 5,800 -8,200 Ω cm 2 to only 162 Ω cm 2 .At a current density up to 1.6 mA cm -2 , the symmetrical batteries exhibit a stable signal voltage of about 190 mV.The maximum voltage fluctuation is less than 7 mV for the batteries during 160 Li-striping/plating cycles at 0.25 mA cm -2 .Excellent electrochemical performance and easy-to-industrial modification method are beneficial for the commercialization of Li metal all-solid-state batteries.