Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料的Ga_(2)O_(3)包覆改性及电化学性能  

Ga_(2)O_(3)coated modification and electrochemical performance of Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)cathode material

作　　者：刘新朋 赵刘洋 李泓漪 陈雅图 吴爱民[1] 李爱魁 黄昊[1] LIU Xinpeng;ZHAO Liuyang;LI Hongyi;CHEN Yatu;WU Aimin;LI Aikui;HUANG Hao(Key Laboratory of Energy Materials and Device(Liaoning Province),School of Materials Science and Engineering,Dalian University of Technology,Dalian,Liaoning 116024,China;Shaanxi Coal Chemical Industry Technology Research Institute Co.,Ltd.,Xi’an 710065,China;School of Electrical Engineering,Dalian University of Technology,Dalian,Liaoning 116024,China)

机构地区：[1]大连理工大学材料科学与工程学院,辽宁省能源材料及器件重点实验室,大连116024 [2]陕西煤业化工技术研究院有限责任公司,西安710065 [3]大连理工大学电气工程学院,大连116024

出　　处：《无机化学学报》2024年第6期1105-1113,共9页Chinese Journal of Inorganic Chemistry

基　　金：陕煤-秦岭基础科学研究五年行动计划资助。

摘　　要：首先采用共沉淀方法制备富锂锰基正极材料Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)原始样品(P-LRMO),然后通过简单的湿化学法以及低温煅烧方法对其进行不同含量Ga_(2)O_(3)原位包覆。透射电子显微镜(TEM)以及X射线光电子能谱(XPS)结果表明在P-LRMO表面成功合成了Ga_(2)O_(3)包覆层。电化学测试结果表明:含有3%Ga_(2)O_(3)的改性材料G3-LRMO具有最优的电化学性能,其在0.1C倍率(电流密度为25 mA·g^(-1))下首圈充放电比容量可以达到270.1 mAh·g^(-1),在5C倍率下容量仍能保持127.4 mAh·g^(-1),优于未改性材料的90.7 mAh·g^(-1),表现出优异的倍率性能。G3-LRMO在1C倍率下循环200圈后仍有190.7 mAh·g^(-1)的容量,容量保持率由未改性前的72.9%提升至85.6%,证明Ga_(2)O_(3)包覆改性能有效提升富锂锰基材料的循环稳定性。并且,G3-LRMO在1C倍率下循环100圈后,电荷转移阻抗(Rct)为107.7Ω,远低于未改性材料的251.5Ω,表明Ga_(2)O_(3)包覆层能提高材料的电子传输速率。To solve the bottleneck problem of lattice oxygen precipitation during the cycling process of lithium-rich manganese-based anode materials and the poor cycling performance due to the lithium-rich phase of the poor con-ductor of electrons,the ultra-wideband semiconductor material Ga_(2)O_(3)for its in-situ coating modification was adopt-ed.The purpose of the surface modification is to improve its electronic conductivity to increase the multiplicity of performance,and at the same time,the C2/m space group of the Ga_(2)O_(3)coating layer can both improve the Li+migra-tion rate and inhibit the Li+migration rate.It can also inhibit the lattice oxygen precipitation of Li-rich manganese-based materials.A pristine sample of Li-rich manganese-based cathode materials Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)(P-LRMO)was prepared by co-precipitation method,and in-situ coated with different contents of Ga_(2)O_(3)by simple wet-chemical method as well as low-temperature calcination method.The results of transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS)showed that the Ga_(2)O_(3)coating layer was successfully synthesized on the sur-face of the pristine sample.The results of electrochemical tests showed that the modified material G3-LRMO with mass fraction of 3%Ga_(2)O_(3)had the best electrochemical performance,which could reach 270.1 mAh·g^(-1)in the first cycle of the charge-discharge at 0.1C(25 mA·g^(-1)),and still maintained 127.4 mAh·g^(-1)at 5C,which was better than 90.7 mAh·g^(-1)of the unmodified material.G3-LRMO still had a capacity of 190.7 mAh·g^(-1)after 200 cycles at 1C,and the capacity retention rate increased from 72.9%to 85.6%,which proves that the modification of Ga_(2)O_(3)coating can improve the cycling stability of lithium-rich manganese-based materials.Moreover,the charge transfer imped-ance(Rct)of the G3-LRMO material was 107.7Ωafter 100 cycles at 1C,which is much lower than that of the unmodified material(251.5Ω),indicating that the Ga_(2)O_(3)coating layer can improve t

关 键 词：锂离子电池 富锂锰基正极材料 Ga_(2)O_(3)包覆 电化学性能 

分 类 号：O614.711[理学—无机化学] TQ131.11[理学—化学] TM912[化学工程—无机化工]