Abstract
Herein, a new solvation strategy enabled by Mg(NO3)2 is introduced, which can be dissolved directly as Mg2+ and NO3− ions in the electrolyte to change the Li+ ion solvation structure and greatly increase interfacial stability in Li-metal batteries (LMBs). This is the first report of introducing Mg(NO3)2 additives in an ester-based electrolyte composed of ternary salts and binary ester solvents to stabilize LMBs. In particular, it is found that NO3− efficiently forms a stable solid electrolyte interphase through an electrochemical reduction reaction, along with the other multiple anion components in the electrolyte. The interaction between Li+ and NO3− and coordination between Mg2+ and the solvent molecules greatly decreases the number of solvent molecules surrounding the Li+, which leads to facile Li+ desolvation during plating. In addition, Mg2+ ions are reduced to Mg via a spontaneous chemical reaction on the Li metal surface and subsequently form a lithiophilic Li–Mg alloy, suppressing lithium dendritic growth. The unique solvation chemistry of Mg(NO3)2 enables long cycling stability and high efficiency of the Li-metal anode and ensures an unprecedented lifespan for a practical pouch-type LMB with high-voltage Ni-rich NCMA73 cathode even under constrained conditions.
Original language | English (US) |
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Pages (from-to) | 2000567 |
Journal | Advanced Energy Materials |
DOIs | |
State | Published - Apr 9 2020 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledgements: This work was mainly supported by a Human Resources Development Program (No. 20184010201720) of a Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant, funded by the Ministry of Trade, Industry and Energy of the Korean government. This work was also supported by a National Research Foundation of Korea (NRF) grant funded by the Korea Government Ministry of Education and Science Technology (MEST) (NRF-2018R1A2B3008794).