標題: Highly concentrated carbonate electrolyte for Li-ion batteries with lithium metal and graphite anodes
作者: Xie, Jian-De
Patra, Jagabandhu
Rath, Purna Chandra
Liu, Weng-Jing
Su, Ching-Yuan
Lee, Sheng-Wei
Tseng, Chung-Jen
Gandomi, Yasser Ashraf
Chang, Jeng-Kuei
交大名義發表
材料科學與工程學系
National Chiao Tung University
Department of Materials Science and Engineering
關鍵字: Li battery;Dendritic Li structure;Electrolyte composition;Coulombic efficiency;Solid electrolyte interface
公開日期: 29-二月-2020
摘要: Highly concentrated lithium bis(fluorosulfonyflimide (LiFSI) salt dissolved in carbonate solvent is employed as a high-performance and robust organic electrolyte for Li-ion batteries. The influences of Li salt type, concentration, and solvent type (such as diethyl carbonate (DEC), dimethyl carbonate (DMC), and ethylene carbonate (EC)) on the electrochemical properties of Li metal and graphite anodes are systematically assessed. A superior electrolyte composition of 5.5 M LiFSI-DMC/EC is achieved, enhancing the anti-flammability, coulombic efficiency, and high rate capability. The optimal efficiency values of Li electrodeposition/stripping utilizing 5.5 M LiFSI-DMC/EC are 97.0% and 94.5% at 0.4 and 6 mA cm(-2), respectively. Such an enhanced performance is due to the formation of a three-dimensional ion network, composed of contact ion pairs (CIPs) and ion aggregates (AGGs) in the highly concentrated LiFSI electrolyte, which effectively decreases the number of free solvent molecules and inhibits the formation of undesired dendritic Li structures. Raman spectroscopy is employed to confirm the formation of CIP and AGG compounds within the electrolyte. The electrochemical data of the 5.5 M LiFSI-DMC/EC electrolyte cell demonstrates a remarkable improvement in the specific capacity and rate capability of a graphite anode.
URI: http://dx.doi.org/10.1016/j.jpowsour.2019.227657
http://hdl.handle.net/11536/153967
ISSN: 0378-7753
DOI: 10.1016/j.jpowsour.2019.227657
期刊: JOURNAL OF POWER SOURCES
Volume: 450
起始頁: 0
結束頁: 0
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