锂离子电池正极材料铌掺杂LiNiO_(2)的制备与电化学性能  

Preparation and electrochemical performance of Nb-doped LiNiO_(2) cathode material for lithium-ion batteries

作　　者：黄丽颖 陆冬楚 宁玉雪 胡婷婷 陈晴 黄国欣 苏静[1] 文衍宣[1] HUANG Liying;LU Dongchu;NING Yuxue;HU Tingting;CHEN Qing;HUANG Guoxin;SU Jing;WEN Yanxuan(School of Chemistry and Chemical Engineering,Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学化学化工学院,广西南宁530004

出　　处：《无机盐工业》2022年第11期52-58,共7页Inorganic Chemicals Industry

基　　金：国家自然科学基金资助项目(51864005);广西自然科学基金(2018GXNSFDA281014);广西大学生创新实验项目(202110593197)。

摘　　要：为了提高LiNiO_(2)的电化学性能,用固相反应法制备了铌掺杂LiNiO_(2)材料,并用X射线衍射(XRD)分析、恒电流滴定技术(GITT)、电化学阻抗谱(EIS)等方法研究铌掺杂量对LiNi O_(2)的结构和性能的影响。结果表明适量的铌(Nb)掺杂可以提高LiNiO_(2)层状结构的有序程度,降低Li^(+)/Ni^(2+)混合程度,降低电荷转移阻抗,提高活性材料中锂离子的扩散系数。其中LiNi_(0.99)Nb_(0.01)O_(2)在0.5C循环100次的容量保持率为91.4%,5C时放电比容量为143 m A·h/g。而未掺杂铌的LiNiO_(2)在相同条件下的容量保持率和比容量仅为69.2%和127 m A·h/g。结果说明铌掺杂能够有效提高LiNiO_(2)的电化学性能。In order to improve the performance of LiNiO_(2),Nb-doped LiNiO_(2)was prepared by a solid-state reaction method.The effects of the amount of Nb-doping on the structure and performance of Li Ni O_(2)were investigated by X-ray diffraction analysis(XRD),galvanostatic titration(GITT),electrochemical impedance spectroscopy(EIS)and other methods.Nbdoping could effectively improve the order degree of the layered structure,reduce Li^(+)/Ni^(2+)mixing,reduce the charge transfer impedance,and increase the diffusion coefficient of Li^(+)in the active materials.Therefore,Li Ni_(0.99)Nb_(0.01)O_(2)exhibited higher capacity retention(91.4%after 100 cycles at 0.5C)and better rate capability(143 m A·h/g at 5C).As a comparison,the data of bare Li Ni O_(2)was 69.2%and 127 m A·h/g under the same conditions.These results further demonstrated that Nb-doping with a strong Nb—O bond,high valence stat,and larger ionic radius could effectively improve the performance of LiNiO_(2).

关 键 词：锂离子电池 正极材料 LiNiO_(2) 掺杂 

分 类 号：TM912.9[电气工程—电力电子与电力传动]