微球LiNi0.8Co0.1Mn0.1O2材料的制备及在改性电解液中的电化学性能 |
Synthesis and Electrochemical Performance in Modified Electrolyte of Microspheres LiNi0.8Co0.1Mn0.1O2 |
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摘要: 利用共沉淀辅以高温烧结法制备了椭球形三元高镍LiNi0.8Mn0.1Co0.1O2(LNCM811)正极材料,并用XRD、SEM和TEM对其结构和形貌进行表征。利用CV和恒流充放电测试LNCM811在添加质量含量分别为2%(w/w) DTD(硫酸乙烯酯)、1%(w/w) MMDS(甲烷二磺酸亚甲酯)及其复合添加剂2% DTD+1% MMDS的电解液中的电化学性能,并利用EIS测试其充放电过程中的动力学特性。结果发现相较于1% MMDS,2% DTD能较为显著提高LNCM811在常温的首周放电容量和首周库伦效率;1% MMDS和2% DTD均能提高电极材料的长循环寿命,室温25℃条件下2% DTD比1% MMDS效果更显著,而高温60℃下1% MMDS比2% DTD更为明显;LNCM811正极无论在室温下还是高温下在复合添加剂的电解液中均具有最好循环性能。EIS测试表明2% DTD+1% MMDS复合添加剂能显著降低LNCM811动力学阻抗。 |
关键词: 锂离子电池 LiNi0.8Mn0.1Co0.1O2正极材料 添加剂 电化学性能 |
基金项目: 中央高校基本科研业务费(No.2015XKMS068)资助项目。 |
Abstract: Microsphere high-nickel ternary LiNi0.8Mn0.1Co0.1O2 (LNCM811) cathode was syntheisized by the chemical co-precipitation method with a simple solid-state reaction, and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM). Electrochemical behavior of LNCM811 was investigated by electrochemical impedance spectroscopy (EIS), combining with cyclic voltammogram (CV) and charge/discharge test in the 1 mol·L-1 LiPF6EC:EMC electrolyte with 2% (w/w) ethylene sulfate (DTD) and 1% (w/w) methylene methanedisulfonate (MMDS) additives either singly or in combination at room temperature of 25℃ or elevated temperature of 60℃. It is found that compared with 1% MMDS, the 2% DTD can slightly improve the initial coulombic efficiency and initial discharge capacity of the LNCM811 at room temperature. Both 2% DTD and 1% MMDS can improve the long cycling performance of LNCM811, and the 2% DTD additive is better than the 1% MMDS additive at 25℃, however, the 1% MMDS is better than the 2% DTD at elevated temperature of 60℃. After long cycles, the LNCM811 cathode has the best cycling performance with additive combination 2% DTD+1% MMDS. EIS results reveal that the additive blend of 2% DTD+1% MMDS can drastically lower the kinetics impedances. |
Keywords: lithium ion battery LiNi0.8Mn0.1Co0.1O2 cathode electrolyte additives electrochemical performance |
投稿时间:2018-01-30 修订日期:2018-04-12 |
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马士平,崔永莉,朱洪刚,左文卿,史月丽,庄全超.微球LiNi0.8Co0.1Mn0.1O2材料的制备及在改性电解液中的电化学性能[J].无机化学学报,2018,34(7):1303-1311. |
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