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 |
顯示於類別: | 期刊論文 |