CoO制备及作为锂离子电池负极电化学性能

Preparation and electrochemical performance of CoO as anode for Li-ion batteries

采用电解法和水热法合成了具有不同形貌的Co(OH)2前驱物,再经过氩气下烧结后分别制备成球形和六边形形貌的CoO颗粒。其中,电解法制备的CoO呈球形颗粒形貌,颗粒尺寸在140~180nm。水热法制备的CoO呈六边形薄片形态,片状尺寸为500~600nm。由于在CoO的六边形薄片形态中,面心立方结构的高密度(111)晶面呈现六边形大表面,故在电化学充放电过程中表现出更多的活性点与较高反应活性。当作为锂离子电池负极材料时,导致六边形薄片的CoO具有呈现出较高的初始容量和良好的稳定性。

In this work,CoO particles with spherical shape and hexagonal configuration were obtained after calcination of Co(OH)2 precursors under Ar atmosphere,which were prepared via electrolysis method and hydrothermal method,respectively.The morphology and structure of the obtained CoO powders were characterized by X-ray diffraction(XRD)and scanning electron microscopy(SEM).It is found that the average particle size of spherical CoO obtained via electrolysis and subsequent sintered process is in the range of 140-180 nm,and the average particle size of CoO with thin hexagonal configuration obtained via hydrothermal method is in the range of 500-600 nm.Because the high density(111)crystal surface of the surface-center cubic structure presents a hexagonal large surface in the form of the hexagonal sheet of CoO,more activity points and higher reaction activity were shown in the electrochemical charge and discharge process.With the obtained CoO as anode materials for Li-ion batteries,CoO with thin hexagonal configuration shows relatively high initial capacity and good cyclic stability.