化学学报 ›› 2001, Vol. 59 ›› Issue (9): 1380-1383. 上一篇    下一篇

研究论文

高容量的Li1.1Mn2O3.95F0.05锂离子二次电池正极材料

陈召勇;刘兴泉;贺益;于作龙   

  1. 中国科学院成都有机化学研究所.成都(610041);中国科学院功能材料开发中心
  • 发布日期:2001-09-15

High capacity Li1.1Mn2O3.95F0.05 cathode materials for Li-ion rechargeable battery

Chen Zhaoyong;Liu Xingquan;He Yi;Yu Zuolong   

  1. Chengdu Inst Organ Chem, CAS.Chengdu(610041)
  • Published:2001-09-15

以无水乙醇为分散剂在行星式球磨机中对原料进行预处理后,经固相反应制备了富锂化合物Li1.1Mn2O3.95F0.05,并以该化合物作为锂离子二次电池正极材料,进行了电化学测试。结果表明,加氟后的富锂化合物Li1.1Mn2O3.95F0.05可与LiCoO2相比,可逆容量高达143nA·h/g,且具有良好的循环稳定性,循环115次后,容量保持率在95%以上。SEM和TEM的表征,说明该方法制备的样品颗粒均匀,具有较好的晶体外观,XRD表征,说明该化合物具有完美的尖晶石结构。锂含量的原子吸收光谱(AAS)表征说明该化合物为富锂化合物Li1.1Mn2O3.95F0.05。电化学测试结果和SEM,TEM,AAS表征支持掺氟后的富锂化合物Li1.1Mn2O3.95F0.05晶胞内空缺增大,使锂离子的嵌入脱出更加容易,并且使更多的锂离子参与嵌入脱出反应。

关键词: 氧化锰, 氧化锂, 氟化合物, 锂离子电池, 电极材料, 扫描电子显微镜, 透射电子显微术, X射线衍射分析

The compound, Li1.1Mn2O3.95F0.05 was synthesized by means of solid - state reaction with precursors ball-milled in planetary micro-mill with alcohol as dispersing liquid, and was electrochemically tested as a cathode material for lithium rechargeable battery. The results showed that the performance of the compound was good, which had a surprising reversible capacity, up to 143mA·h/g, which was almost equivalent to that of LiCoO2. Furthermore, it exhibited satisfactory cyclic stability, with above 95% retainable capacity after cycling 115 times. SEM and TEM showed the sample were uniform particles with good crystal morphology. XRD analysis identified that the compound had a spinel structure of LiMn2O4. Atomic absorption spectroscope (AAS) proved that this compound was Li-rich Li1.1Mn2O3.95F0.05. Electrochemical test results, SEM, TEM, XRD and AAS supported that in Li-rich Li1.1Mn2O3.95F0.05, the added fluorine made the crystal space becoming larger and the intercalation- deintercalation of lithium ions was much easier and more lithium ions were involved into the reaction.

Key words: MANGANESE OXIDE, LITHIUM OXIDE, FLUORINE COMPOUNDS, SCANNING ELECTRON MICROSCOPES, TRANSMISSION ELECTRON MICROSCOPY, X-RAY DIFFRACTION ANALYSIS

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