Designing a Li-Metal Battery to Surviving in Practical Operating Condition for Electric Vehicle Applications

We propose a new breakthrough in realizing a practical Li-metal battery capable of fast charging while delivering a high energy density. To stabilize the Li metal anode, the electrolyte, consisting of 1M LiPF 6 and 0.05M lithium difluoro(oxalate)borate (LiDFOB) dissolved in the mixture of ethyl methyl carbonate (EMC) and fluoroethylene carbonate (FEC) solution, ensures a stable robust solid electrolyte interphase (SEI) layer on the anode surface. LiNO 3 pretreatment of the Li-metal anode adds a prior Li 2 O-rich SEI layer that provides the mechanical strength to maintain the SEI layer from breakdown against to dendritic Li growth at extremely high charge current density. Meanwhile, Al-doped full-concentration-gradient Li[Ni 0.75 Co 0.10 Mn 0.15 ]O 2 cathode provides the necessary cycling stability at a high cathode loading level. Integrating these components produced a LMB that allowed a high areal capacity of 4.1 mAh cm -2 and accomplished an unprecedented cycling stability over 300 cycles at a high current density of 3.6 mA cm -2 . In addition, proposed LMB can further extended when moderate capacity loading of 2.0 mAh cm -2 under ultra-fast charging-discharging conditions; specifically, the LMB showed excellent long-term cycling stability up to 500 cycles under charge at 3.6 mA cm -2 (30 min) but discharge with 9 mA cm -2 (12 min). We believe that our findings presented herein provide new perspectives for the development of practical LMBs that satisfy the capacity and charging rate requirements for future electric vehicles. Reference 1. J.-Y. Hwang, S.-J. Park, C. S. Yoon and Y.-K. Sun, Energy Environ. Sci., 2019, 12, 2174. 2. S.-J. Park, J.-Y. Hwang, C. S. Yoon, H.-G. Jung and Y.-K. Sun, ACS Appl. Mater. Interfaces, 2018, 10, 17985. 3. Y.-K. Sun, Z. Chen, H.-J. Noh, D.-J. Lee, H.-G. Jung, Y. Ren, S. Wang, C. S. Yoon, S.-T. Myung and K. Amine, Nat. Mater., 2012, 11, 942.