Lithium Dendrite Suppressing Effect of Fluoroethylene Carbonate Additive on Surface Patterned Lithium Metal

Abstract

Due to the highest possible theoretical capacity (3860 mAh g-1 or 2060 mAh cm-3) and the lowest negative electrochemical potential (-3.04 V vs standard hydrogen electrode) lithium (Li) metal has been considered as the promising anode material for achieving a battery of high energy density. Nevertheless, the successful implementation of Li metal in the secondary battery system has been delayed due to the uncontrolled dendrite growth during repeated Li deposition/stripping process, resulting the capacity and safety degradation of battery system. Recently, our group suggested to use the surface-patterned Li metal to suppress Li dendrite growth though a stamping technique [1-2]. We observed that the surface pattern was filled by granular forms of Li metal when the Li plating was conducted at a high current density condition. These can cause the consumption of large amount of Li ions to form solid electrolyte interface (SEI) on the newly exposed Li metal surface. Herein, we investigated the Li dendrite impeding effect of FEC on the surface-patterned Li metal during the repeated Li plating processes at high current density. The effect of the FEC additive was characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). Acknowledgements This work was supported by the international Collaborative Energy Technology R&D Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea. (No. 20158510050020). Reference 1. M.-H. Ryou, and Y. M. Lee, Y. Lee, M. Winter, P. Bieker, Advanced Functional Materials 2015, 25, 834-841 2. J. Park, J. Jeong, Y. Lee, M. Oh, M.-H. Ryou, and Y. M. Lee, Advanced Materials Interfaces 2016, 1600140