Mg^(2+)掺杂对富锂层状氧化物材料Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)的影响  

Effect of Mg^(2+)Doping on Li⁃Rich Layered Oxides Materials Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)

作　　者：解自奇 谭玉婷 赵妮 周明东[1] 颜文超 XIE Ziqi;TAN Yuting;ZHAO Ni;ZHOU Mingdong;YAN Wenchao(School of Petrochemical Engineering,Liaoning Petrochemical University,Fushun Liaoning 113001,China;School of Materials Science and Engineering,Linyi University,Linyi Shandong 276000,China)

机构地区：[1]辽宁石油化工大学石油化工学院,辽宁抚顺113001 [2]临沂大学材料科学与工程学院,山东临沂276000

出　　处：《辽宁石油化工大学学报》2024年第2期22-28,共7页Journal of Liaoning Petrochemical University

基　　金：国家自然科学基金青年科学基金项目(21905124)。

摘　　要：Mg^(2+)作为一种电化学惰性的阳离子,由于其离子半径(0.072 nm)与Li^(+)的离子半径(0.076 nm)相近,因此被广泛应用于取代富锂层状氧化物(LLOs)材料中Li^(+)的位置。然而,Mg^(2+)对LLOs材料晶体结构的影响还存在争议。利用溶胶凝胶法成功制备了一系列Mg^(2+)掺杂富锂正极材料Li_(1.2-x)Mg_(x)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2),通过X射线衍射仪和X射线光电子能谱等对其晶体结构和元素价态进行了系统的研究。结果表明,Mg^(2+)掺杂导致LLOs材料晶胞参数的增加。通过与Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)材料的电化学性能对比发现,Mg^(2+)掺杂有效地提高了LLOs材料的电化学性能。经过优化后,Mg-0.03样品展现出最优异的电化学性能,在0.1 C倍率下的初始放电比容量为291.9 mA•h/g,首圈库伦效率为78.40%。As an electrochemical inert cation,Mg^(2+)has an ionic radius(0.072 nm)similar to that of Li^(+)(0.076 nm),which is widely used to replace Li^(+)in Li-rich layered oxides(LLOs)materials.However,the influence of Mg^(2+)on the crystal structure of LLOs materials is still controversial.In this work,the Mg-doped Li-rich cathode materials Li_(1.2-x)Mg_(x)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)were synthesized by a sol-gel and high-temperature calcination method.The crystal structure,and valence state of elements in synthesized materials were systematically studied via X-ray diffraction,and X-ray photoelectron spectroscopy.These results indicated that Mg^(2+)doping can increase the cell parameters of LLOs materials.At the same time,compared with Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2),Mg-doping can effectively improve the electrochemical performance of LLOs materials.After optimization,the Mg-0.03 sample exhibits anomalous electrochemical performance,that is,the initial discharge-specific capacity is 291.9 mA•h/g and the initial coulomb efficiency is 78.40%.

关 键 词：锂离子电池 富锂层状氧化物 正极材料 溶胶凝胶法 Mg^(2+)掺杂 

分 类 号：TQ131.11[化学工程—无机化工] TM912.9[电气工程—电力电子与电力传动]