共沸蒸馏法制备高性能LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2正极材料

三元复合氧化物镍钴锰酸锂(LiNi1/3Co1/3Mn1/3O2)因兼有LiNiO2和LiCoO2的优点,被认为是最有可能取代LiCoO2的新型正极材料而受到广泛关注.本文采用一种改进的共沉淀方法合成了LiNi1/3Co1/3Mn1/3O2,以共沸蒸馏干燥前驱物.结果表明,共沸干燥法最终得到的产物比普通干燥法得到的产物具有更高的比容量、更好的循环性能以及更优的倍率性能.究其原因,可归结为共沸干燥得到的样品颗粒更小,且粒径分布更均匀,球形度高,比表面积大,促进了锂离子的扩散,因而提高了其电化学性能.

Synthesis of High-Performance LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 Cathode Materials via Azeotropic Distillation Method

Layered LiNi1/3Co1/3Mn1/3O2 is one of the most promising alternative materials for LiCoO2 in lithium ion batteries due to its low cost,large capacity and excellent cyclability.In this paper,LiNi1/3 Co1/3 Mn1/3 O2 was synthesized via azeotropic distillation method with isobutyl alcohol as an azeotropic agent.The structure and surface morphology were characterized by X-ray diffraction(XRD) and scanning electron microscope(SEM),respectively.The as-prepared LiNi1/3Co1/3Mn1/3O2 shows a layered α-NaFeO2 structure;the particles are small and uniformly distributed.As compared with the sample prepared by traditional method,the present cathode material exhibits superior cyclability and rate capability,which can be ascribed to the enhanced Li + diffusion due to smaller and more uniform particles caused by the addition of the azeotropic agent during preparation.