摘要
目前,工业产品的三元正极材料LiNi0.5Co0.2Mn0.3O2通常使用间接共沉淀和高温固相烧结相结合的方法.共沉淀制得的氢氧化镍钴锰前驱体,其形貌和粒径分布等直接影响着三元材料LiNi0.5Co0.2Mn0.3O2的性能.使用X射线衍射(XRD)、扫描电镜(SEM)表征和观察材料晶体结构和表面形貌,并测试粒径分布、振实密度和电化学性能,考察三种前驱体对制得的三元材料的影响.研究结果表明,前驱体的粒径分布直接影响材料的物理性能,表面有大量微孔而又致密的球形是较理想的前驱体形貌;焙烧后可得到结晶度高的材料,0.2C全电池放电比容量达到156.4 mAh·g-1,循环寿命优异,300周期循环其容量基本不衰减,500周期循环后容量保持率高达92%.
Commercial LiNi0.5Co0.2Mn0.3O2material is generally prepared by a combination of co-precipitation and solid state reaction method.The particle size distribution and morphology of Ni0.5Co0.2Mn0.3（OH）2 precursor have a great impact on the electrochemical performance of LiNi0.5Co0.2Mn0.3O2.In this work,the crystal structure and surface morphology of LiNi0.5Co0.2Mn0.3O2 prepared by three different precursors were characterized by X-ray diffraction（XRD） and scanning electron microscopy（SEM）.Particle size distribution,tap density and electrochemical performance were investigated.The results show that the particle size distribution of every precursor has most direct impact on properties of the corresponding LiNi0.5Co0.2Mn0.3O2.The precursor with micropores on surface results in the best electrochemical performance.The discharge capacity for full cell test was 156.4 mAh.g-1（0.2C）,meanwhile,the cycling performance is excellent.The capacity fading was limited in the first 300 cycles with up to 92% capacity retention after 500 cycles.
出处
《电化学》
CAS
CSCD
北大核心
2013年第3期204-209,共6页
Journal of Electrochemistry
基金
上海市分子催化和功能材料重点实验室(No.08DZ2270500)资助
