Non-Flammable Dual-Salt Deep Eutectic Electrolyte for High-Voltage Lithium Metal Battery
Wanbao Wu,
Qing Li,
Miaomiao Cao,
Deping Li,
Jingyu Lu,
Mingyu Li,
Jiaheng Zhang
Affiliations
Wanbao Wu
Research Centre of Printed Flexible Electronics, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
Qing Li
Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
Miaomiao Cao
Research Centre of Printed Flexible Electronics, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
Deping Li
State Key Laboratory of Advanced Welding and Joining, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
Jingyu Lu
School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
Mingyu Li
Research Centre of Printed Flexible Electronics, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
Jiaheng Zhang
Research Centre of Printed Flexible Electronics, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
The application of high voltage cathode electrode materials is an effective way to increase the energy density of batteries. However, the development and design of a stable electrolyte at high voltages needs to be further addressed. Herein, we developed a non-flammable dual-salt deep eutectic solvent (DES) as a safe electrolyte containing LiTFSI, LiDFOB, and succinonitrile in different molar ratios. This non-flammable DES provides high ionic conductivity (4.23 mS cm−1) at 25 °C, high Li+ transference number (0.75), and wide electrochemical stability (>5.5 V). When using the designed DES electrolytes in high voltage LiCoO2||Li cells, superior electrochemical performance was achieved at cut-off voltages of 3.0–4.45 V and 3.0–4.6 V, even at a high current density of 2 C. This work offers an in-depth understanding of the critical role of dual-salts in DES and provides an approach to designing safe electrolytes for high voltage LiCoO2||Li cells.
