中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 21 No. 1 January 2011 |
lithium-ion batteries
（1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. Department of Chemistry and Materials Science, Hunan Institute of Humanities, Science and Technology,
Loudi 417000, China）
Abstract:Layered Li[Ni1/3Co1/3Mn1/3]O2 was synthesized with complex metal hydroxide precursors that were prepared by a co-precipitation method. The influence of coordination between ammonia and transition-metal cations on the structural and electrochemical properties of the Li[Ni1/3Co1/3Mn1/3]O2 materials was studied. It is found that when the molar ratio of ammonia to total transition-metal cations is 2.7:1, uniform particle size distribution of the complex metal hydroxide is observed via scanning electron microscopy. The average particle size of Li[Ni1/3Co1/3Mn1/3]O2 materials was measured to be about 500 nm, and the tap-density was measured to be approximately 2.37 g/cm3, which is comparable with that of commercialized LiCoO2. XRD analysis indicates that the presently synthesized Li[Ni1/3Co1/3Mn1/3]O2 has a hexagonal layered-structure. The initial discharge capacity of the Li[Ni1/3Co1/3Mn1/3]O2 positive-electrode material is determined to be 181.5 mA∙h/g using a Li/Li[Ni1/3Co1/3Mn1/3]O2 cell operated at 0.1C in the voltage range of 2.8−4.5 V. The discharge capacity at the 50th cycle at 0.5C is 170.6 mA∙h/g.
Key words: layered structure; coordination effect; hydroxide co-precipitation; cathode material; lithium ion batteries
