Influence of fluoroethylene carbonate as co-solvent on the high-voltage performance of LiNi_1/3Co_1/3Mn_1/3O₂ cathode for lithium-ion batteries

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• 作者：Long Wang ; Yulin Ma ; ^{mayulin@hit.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Yunteng Qu ; Xinqun Cheng ; Pengjian Zuo ; Chunyu Du ; Yunzhi Gao ; ^{gao_yunzhihit@hit.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Geping Yin
• 关键词：High voltage ; LiNi1/3Co1/3Mn1/3O2 ; Fluoroethylene carbonate ; Lithium-ion battery
• 刊名：Electrochimica Acta
• 出版年：2016
• 出版时间：10 February 2016
• 年：2016
• 卷：191
• 期：Complete
• 页码：8-15
• 全文大小：1030 K

文摘

In this work, the electrochemical performance of LiNi_1/3Co_1/3Mn_1/3O₂ cathode is investigated under high voltage with fluoroethylene carbonate (FEC) as co-solvent for lithium ion battery. Charge/discharge tests show that the cycling and rate performances of LiNi_1/3Co_1/3Mn_1/3O₂ are dramatically improved at high voltage operation when ethylene carbonate (EC) is replaced by FEC in electrolyte solution. After 100 cycles between 3.0 and 4.6 V (vs. Li/Li⁺) at 0.2C rate, the capacity retention of LiNi_1/3Co_1/3Mn_1/3O₂ with FEC/dimethyl carbonate (DMC) (1/4, vol.%) solution is 82.7%, while the EC-containing electrolyte is only 41.3%. The effects of FEC on the high-voltage performance and the surface properties of the LiNi_1/3Co_1/3Mn_1/3O₂ cathode are characterized by electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). It is found that FEC as co-solvent participates in the formation of protective surface films on the LiNi_1/3Co_1/3Mn_1/3O₂ cathode, which efficiently suppresses the decomposition of the electrolyte, prevents the severe structure destruction and improves the cycling stability and rate capability of LiNi_1/3Co_1/3Mn_1/3O₂ electrode under high voltage.