1H,1H,5H-Perfluoropenty1-1,1,2,2-tetrafluoroethylet her as a co-solvent for high voltage LiNi1/3Co1/3Mn1/3O2/graphite cells

作者：Wang, Chengyun; Zuo, Xiaoxi^*; Zhao, Minkai; Xiao, Xin; Yu, Le; Nan, Junmin^*

来源：Journal of Power Sources, 2016, 307: 772-781.

DOI：10.1016/j.jpowsour.2016.01.047

• 1H,1H,5H-Perfluoropenty1-1,1,2,2-tetrafluoroethylether
• High voltage
• Solvent
• LiNi1/3Co1/3Mn1/3O2/graphite

1H,1H,5H-Perfluoropenty1-1,1,2,2-tetrafluoroethylether (F-EAE) mixed with ethylene carbonate (EC), diethyl carbonate (DEC), and lithium hexafluorophosphate (LiPF6) is evaluated as a co-solvent high potential electrolyte of LiNi1/3Co1/3Mn1/3O2/graphite batteries. Linear sweep voltammetry (LSV) and cyclic voltammetry (CV) indicate that the EC/DEC-based electrolyte with F-EAE possesses a high oxidation potential (>5.2 V vs. Li/Li+) and excellent film-forming characteristics. With 40 wt% F-EAE in the electrolyte, the capacity retention of the LiNi1/3Co1/3Mn1/3O2/graphite pouch cells that are cycled between 3.0 and 4.5 V is significantly improved from 28.8% to 86.8% after 100 cycles. In addition, electrochemical impedance spectroscopy (EIS) of three-electrode pouch cells, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) are used to characterize the effects of F-EAE on the enhanced capacity retention. It is demonstrated that F-EAE facilitates the formation of a stable surface electrolyte interface (SEI) layer with low impedance on the anode and effectively suppresses an increase in the charge-transfer resistance on the cathode. These results suggest that F-EAE can serve as an alternative electrolyte solvent for 4.5 V high voltage rechargeable lithium-ion batteries.

• 出版日期2016-3-1
• 单位华南师范大学