摘要
采用共沉淀-喷雾造粒法制备前驱体,于700℃在空气中煅烧20h合成出层状LiNi1/2-xCo2xMn1/2-xO2正极材料,研究了不同掺钴量对材料的结构和电化学性能的影响,并用XRD、SEM及电性能测试考察了所得材料的结构、形貌与电化学性能。XRD分析表明,LiNi1/2-xCo2xMn1/2-xO2是具有α-NaFeO2层状结构的纯相物质,Co3+的掺入可促进层状结构的生成,有效减少阳离子混排。电性能测试结果显示,LiNi1/2-xCo2xMn1/2-xO2随着掺钴量的增大,放电容量提高,循环性能变好。样品Li(Ni1/3Co1/3Mn1/3)O2表现出最好的电化学性能,其首次放电效率充放电效率达90%,首次放电容量为172.8mAh/g,40次循环容量无衰减。
The precipitate-spray method was used to prepare the precursor. The layered LiNi1/2-xCo2xMn1/2-xO2 cathode material for lithium ion batteries was synthesized in air atmosphere at 750℃ for 20 h from precursors. XRD analysis, SEM and electrochemical tests were used to characterize the structure, appearance and electrochemical performances of the aimed material. The results of XRD showed that all LiNi1/2-xCo2xMn1/2-xO2 were pure phase materials with layeredα- NaFeO2 structure, and the Co content can effectively restrained the cation-mixing and nonstoichiometric products. The electrochemical tests indicated that the discharge capacities of LiNi1/2-xCo2xMn1/2-xO2 increased and the cycle performances became better with the content of Co increasing. The sample Li（Ni1/3 CO1/3 Mn1/3 ）O2 had best electrochemical properties, which had an initial charge capacity of 172.8mAh/g and an initial efficiency of 90%. After 40 cycles, this sample preserved 100% of the initial discharge capacity, showing perfect cyclic stability.
出处
《化工新型材料》
CAS
CSCD
北大核心
2008年第6期68-71,共4页
New Chemical Materials
