High capacity 0.5Li2MnO3·0.5LiNi0.33Co0.33Mn0.33O2 cathode material via a fast co-precipitation method
High capacity 0.5Li2MnO3·0.5LiNi0.33Co0.33Mn0.33O2 cathode material via a fast co-precipitation method
复制标题
DOI：
10.1016/j.electacta.2012.09.024
复制
发表时间：
2013
影响因子：
6.6
通讯作者：
Y. Chen;Guofeng Xu;Jianling Li;Yakun Zhang;Zhong-Cai Chen;F. Kang
中科院分区：
文献类型：
--
作者：
Y. Chen;Guofeng Xu;Jianling Li;Yakun Zhang;Zhong-Cai Chen;F. Kang
以高溶解度的硫酸盐作为混合氢氧化物前驱体的过渡金属源，采用快速共沉淀法合成了0.5Li2MnO3·0.5LiNi0.33Co0.33Mn0.33O2（或Li[Li0.2Mn0.54Ni0.13Co0.13]O2）固溶体材料。通过正交实验确定了最佳合成条件。对最佳条件下合成的样品的性能进行了详细的研究。0.5Li2MnO3·0.5LiNi0.33Co0.33Mn0.33O2的XRD图谱显示出有序的六方层状结构，具有明显的超晶格特征。FESEM结果表明，粉体颗粒细小，无团聚，粒径在100- 300 nm之间。XPS分析结果表明，Ni、Co、Mn的价态分别为+2、+3、+3.52。电化学测试结果表明，该材料在1/20 C、2.0 ~ 4.8V之间的初始放电容量为315.3mAhg− 1，在最初几次循环后具有良好的循环稳定性。循环伏安测试表明，高容量性能归因于氧或其物种在电极表面的氧化还原。速率测试表明，在2C下获得了179.5mAhg− 1，就我们而言，这是相当高的。
Solid solution material of 0.5Li2MnO3·0.5LiNi0.33Co0.33Mn0.33O2(alternatively Li[Li0.2Mn0.54Ni0.13Co0.13]O2) was synthesized by a fast co-precipitation method which takes sulfates with high solubility as the transition metal sources of mixed hydroxide precursor. The optimal synthetic conditions were determined through the design of orthogonal experiments. The properties of samples synthesized under the best conditions were investigated in detail. The XRD pattern of 0.5Li2MnO3·0.5LiNi0.33Co0.33Mn0.33O2revealed a well ordered hexagonal layered structure with the evident feature of super lattice caused by Li2MnO3. FESEM images showed that the powders possess small and unagglomerated particles with size range of 100–300nm. XPS analysis results demonstrated that the valence states of Ni, Co, Mn are +2, +3, and +3.52 respectively. The electrochemical measurements showed that the optimal material delivers initial discharge capacity of 315.3mAhg−1at 1/20C between 2.0 and 4.8V with good cycle stability after firstly several cycles. CV test proved that the high capacity performance is ascribed to the redox of oxygen or its species at the electrode surface. Rate test showed that 179.5mAhg−1was obtained at 2C which is considerably high, as far as we concerned.