Developing a Water-Defendable and Dendrite-Free Lithium-Metal Anode Using a Simple and Promising GeCl4 Pretreatment Method

Lithium metal is an ultimate anode in next-generation rechargeable batteries, such as Li-sulfur batteries and Li-air (Li-O-2) batteries. However, uncontrollable dendritic Li growth and water attack have prevented its practical applications, especially for open-system Li-O-2 batteries. Here, it is reported that the issues can be addressed via the facile process of immersing the Li metal in organic GeCl4-THF steam for several minutes before battery assembly. This creates a 1.5 mu m thick protection layer composed of Ge, GeOx, Li2CO3, LiOH, LiCl, and Li2O on Li surface that allows stable cycling of Li electrodes both in Li-symmetrical cells and Li-O-2 cells, especially in moist electrolytes (with 1000-10 000 ppm H2O) and humid O-2 atmosphere (relative humidity (RH) of 45%). This work illustrates a simple and effective way for the unfettered development of Li-metal-based batteries.