Monday, 4 March 2019
Areas Adjacent to the Forum (Scripps Seaside Forum)
Lithium metal is being extensively studied as an anode to replace graphite due to its high capacity and the lowest negative electrochemical potential. Current research focus is to mitigate lithium dendrite growth and to increase coulomb efficiency during electrochemical cycling by using various surface coatings, electrolyte additives.1, 2 In addition, a 3D host can be beneficial due to the reduced volume change.3 We have recently focused on designing novel electrolyte solution chemistry that enables dendrite free Li metal cycling. The structure, physical and chemical properties of the designed electrolyte solution are well in accordance with the quantum chemistry calculations. The XPS analysis of the SEI (solid electrolyte interface) components on the Li metal surface reveals that a LiF rich protection layer forms. As a result, a high average coulombic efficiency of 99.4% has been achieved at 0.5 mA cm-2 for 1 mAh cm-2 over 900 cycles. Even at a high current density of 10 mA cm-2, the coulombic efficiency of Li metal in this novel electrolyte is above 98.5%. A Li metal full cell with PANS (Poly(acrylonitrile) Sulfur) as cathode realizes a capacity retention of >98% over 900 cycles. This study offers a promising approach to enable highly stable Li metal battery applications.
Acknowledgements
This work was supported by the Office of Vehicle Technologies of the U.S. Department of Energy through the Advanced Battery Materials Research Program (Battery 500 Consortium) under Contract DE-EE0007764. Part of the work used the UCSD-MTI Battery Fabrication Facility and the UCSD-Arbin Battery Testing Facility.
- H. Liu, X. Wang, H. Zhou, H.-D. Lim, X. Xing, Q. Yan, Y. S. Meng and P. Liu, ACS Applied Energy Materials, 2018, DOI: 10.1021/acsaem.8b00348.
- H. Liu, H. Zhou, B.-S. Lee, X. Xing, M. Gonzalez and P. Liu, Acs Applied Materials & Interfaces, 2017, 9, 30635-30642.
- H. Liu, X. Yue, X. Xing, Q. Yan, J. Huang, V. Petrova, H. Zhou and P. Liu, Energy Storage Materials, 2018, DOI: https://doi.org/10.1016/j.ensm.2018.09.021.