A robust interphase via in-situ pre-reconfiguring lithium anode surface for long-term lithium-oxygen batteries

Abstract

Lithium-oxygen (Li-O2) battery is considered as one of the most promising alternatives because of its ultrahigh theoretical energy density. However, their cycling stability is severely restricted by the uncontrollable dendrite growth and serious oxygen corrosion issue on Li surface. Herein, a sulfur-modified Li surface can be successfully constructed via chemical reaction of guanylthiourea (GTU) molecule on Li, which can induce the selectively fast decomposition of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) to form a smooth and stable inorganics-rich solid-electrolyte interphase (IR-SEI) during the subsequent electrochemical process. Such an IR-SEI cannot only offer a highly reversible and stable Li plating/stripping chemistry with dendrite-free property (10 mA cm−2-10 mAh cm−2, > 0.5 years; 3 mA cm−2-3 mAh cm−2, > 1 year) but also endows the Li metal an anti-oxygen corrosion function, thereby significantly improving the cycling stability of Li-O2 batteries. This work provides a new idea for constructing functional solid-electrolyte interphase (SEI) to achieve highly stable Li metal anode.