Screening of F-containing electrolyte additives and clarifying their decomposition routes for stable Li metal anodes.

Liu, Jijiang; Hao, Wei; Fang, Mingming; Chen, Xin; Dong, Yongteng; Chen, Yuanmao; Wang, Zhiyong; Yue, Xinyang et al. · Nat Commun · 2024

basic_science · Level V

Where this comes from

Abstract

Constructing a LiF-rich solid electrolyte interphase (SEI) is a feasible strategy for inhibiting lithium (Li) dendrites of Li metal anodes (LMAs). However, selecting appropriate F-containing additives with efficient LiF contribution is still under active research. Herein, a series of fluorinated additives with diverse F/C molar ratios are investigated, and we demonstrate that the hexafluoroglutaric anhydride (F<sub>6-0</sub>) holds the best capability to derive the LiF-rich SEI in regular carbonate electrolytes (RCEs). To ameliorate the decomposition kinetics of the F<sub>6-0</sub>, LiNO<sub>3</sub> (LNO) as an adjuvant is further introduced in the system. As a result, the reduction efficiency of F<sub>6-0</sub> is increased to 91% under the F<sub>6-0</sub>/LNO synergistic effect, enabling the LMA with a uniform LiF-rich SEI in the RCE with merely 4 vol. % F<sub>6-0</sub>/LNO (F6L) addition. The LiNi<sub>0.8</sub>Co<sub>0.1</sub>Mn<sub>0.1</sub>O<sub>2</sub>||Li-20μm full-cell with the F6L also showcases better cycling and rate performances than the cases with other F-containing additives.