Bioinspired Polysulfiphobic Artificial Interphase Layer on Lithium Metal Anodes for Lithium Sulfur Batteries

The application of Li-S batteries suffers from many issues, polysulfide dissolution in particular. The fresh Li metal reacts with polysulfide continuously, which aggravates irregular Li plating/stripping behavior and decomposition of organic electrolyte resulting in short cycle life and low Coulombic efficiency. Nature has provided a lot of inspiration for human to realize structural construction and functional integration, as it does to battery design. In this report, learning from the hydrophobic property of natural species, a scaly polysulfiphobic artificial interphase layer are constructed on lithium metal anodes that can repel LiPS through the functional decylphosphonate groups that are proved by in operando XPS with Ar ion sputtering. Moreover, the obtained artificial interphase layer keeps dendrite-free morphology and restrains side reactions during cycling effectively. In situ XRD measurements are employed to demonstrate the inhibiting effect for decomposition of organic electrolyte. The as-obtained LDP-Li anodes exhibit outstanding electrochemical performance with the specific capacity of ∼1000 mAh g^-1 corresponding to Coulombic efficiency of nearly 99%, which shows great promise for the application of Li-S batteries.