Zinc anode-compatible in-situ solid electrolyte interphase via cation solvation modulation

• Published in: Nature communications Vol. 10; no. 1; pp. 5374 - 12
• Main Authors: Qiu, Huayu, Du, Xiaofan, Zhao, Jingwen, Wang, Yantao, Ju, Jiangwei, Chen, Zheng, Hu, Zhenglin, Yan, Dongpeng, Zhou, Xinhong, Cui, Guanglei
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 26-11-2019; Nature Publishing Group; Nature Portfolio
• Subjects: 140/133; 140/146; 140/58; 147/135; 639/4077/4079/891; 639/638/161/891; 639/638/675; Anodes; Anodic protection; Batteries; Cycles; Dendritic structure; Electrolytes; Fluorides; Humanities and Social Sciences; Interphase; Ion migration; Mechanical properties; multidisciplinary; Organic chemistry; Rechargeable batteries; Redox potential; Science; Science (multidisciplinary); Solid electrolytes; Solvation; Surface chemistry; Zinc; Zinc fluorides; Zinc plating
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-13436-3

The surface chemistry of solid electrolyte interphase is one of the critical factors that govern the cycling life of rechargeable batteries. However, this chemistry is less explored for zinc anodes, owing to their relatively high redox potential and limited choices in electrolyte. Here, we report the observation of a zinc fluoride-rich organic/inorganic hybrid solid electrolyte interphase on zinc anode, based on an acetamide-Zn(TFSI)
2
eutectic electrolyte. A combination of experimental and modeling investigations reveals that the presence of anion-complexing zinc species with markedly lowered decomposition energies contributes to the in situ formation of an interphase. The as-protected anode enables reversible (~100% Coulombic efficiency) and dendrite-free zinc plating/stripping even at high areal capacities (>2.5 mAh cm
‒2
), endowed by the fast ion migration coupled with high mechanical strength of the protective interphase. With this interphasial design the assembled zinc batteries exhibit excellent cycling stability with negligible capacity loss at both low and high rates.
Zinc chemistry is not favourable to the formation of a solid electrolyte interphase as a result of its high redox potential. In a break with the traditional wisdom, the present authors realise ZnF
2
-rich hybrid SEI on Zn anode via the modulation of cationic speciation in a eutectic electrolyte.