Challenges facing high-voltage/high-capacity cathodes, in addition to the longstanding problems pertinent to lithium (Li)-metal anodes, should be addressed to develop high-energy-density Li-metal batteries. This issue mostly stems from interfacial instability between electrodes and electrolytes. Conventional carbonate- or ether-based liquid electrolytes suffer from not only volatility and flammability but also limited electrochemical stability window. Here, we report a nitrile electrolyte strategy based on concentrated nitrile electrolytes (CNEs) with co-additives. The CNE consists of high-concentration lithium bis(fluorosulfonyl)imide (LiFSI) in a solvent mixture of succinonitrile (SN)/acetonitrile (AN). The SN/AN solvent mixture is designed to ensure high oxidation stability along with thermal stability, which are prerequisites for high-voltage Li-metal cells. The CNE exhibits interfacial stability with Li metals due to the coordinated solvation structure. Lithium nitrate (LiNO3) and indium fluoride (InF3) are incorporated in the CNE as synergistic co-additives to further stabilize solid-electrolyte interphase (SEI) on Li metals. The resulting electrolyte (CNE + LiNO3/InF3) enables stable cycling performance in Li||LiNi0.8Co0.1Mn0.1 and 4.9 V-class Li||LiNi0.5Mn1.5O4 cells. Notably, the Li||LiNi0.5Mn1.5O4 cell maintains its electrochemical activity at high temperature (100 °C) and even in flame without fire or explosion.
|Journal||Energy and Environmental Materials|
|Publication status||Accepted/In press - 2022|
Bibliographical noteFunding Information:
H.M. and S.C. contributed equally to this work. This work was supported by the U.S. Army Research Office (ARO) (W911NF‐18‐1‐0016). This work was also supported by the Basic Science Research Program (2021R1A2B5B03001615 and 2021M3H4A1A02099355) through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning, the Technology Innovation Program (20010960 and 20012216) funded by the Ministry of Trade, Industry & Energy (MOTIE), and the R&D program for Forest Science Technology (FTIS 2021354D10‐2123‐AC03) provided by Korea Forest Service (Korea Forestry Promotion Institute).
© 2022 Zhengzhou University.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)
- Water Science and Technology
- Environmental Science (miscellaneous)
- Waste Management and Disposal
- Energy (miscellaneous)