金属离子掺杂LiFePO_(4)正极材料的制备及其电化学性能研究  

Preparation and electrochemical properties of LiFePO_(4) cathode materials doped with metal ions

作　　者：王林玉 何志芳 WANG Linyu;HE Zhifang(College of Chemical Engineering and Materials,Handan University,Handan 056005,China;Hebei Center for New Inorganic Optoelectronic Nanomaterial Research,Handan 056005,China)

机构地区：[1]邯郸学院化学化工与材料学院,河北邯郸056005 [2]河北省高校纳米无机光电新材料应用技术研发中心,河北邯郸056005

出　　处：《功能材料》2024年第7期7177-7182,共6页Journal of Functional Materials

基　　金：河北省高等学校科学研究项目(BJ2020209);邯郸市科学技术研究与发展计划项目(23422021131ZC)。

摘　　要：选择金属Ag为掺杂元素,通过溶胶-凝胶法制备了Ag掺杂的LiFePO_(4)正极材料,并以此组装了CR2032扣式电池,研究了金属Ag掺杂摩尔比对LiFePO_(4)的物相结构、微观形貌和对应电池电化学性能的影响。结果表明,Ag掺杂的LiFePO_(4)具有橄榄石型结构,外观为棒状的小颗粒,颗粒尺寸的长度约为350~500 nm,宽度约为100 nm,颗粒之间有轻微的团聚。不同摩尔比Ag掺杂的LiFePO_(4)正极材料的充放电效率均超过95%,适量Ag摩尔比的掺杂改善了LiFePO_(4)的循环稳定性能、初始放电比容量和容量保持率。随着Ag掺杂摩尔比的增大,LiFePO_(4)的最大放电比容量先增大后降低,Ag摩尔比3%的LiFePO_(4)的放电比容量达到最大值为123.4 mAh/g,经过30次循环后放电比容量最大为70.4 mAh/g,容量保持率最大为57.05%,对应的电荷转移电阻为632.7Ω。可见,3%Ag-LiFePO_(4)的综合性能最佳。Ag doped LiFePO_(4) cathode material was prepared by sol-gel method with Ag as the doping element,and CR2032 button cell was assembled based on it.The influence of metal Ag doping molar ratio on the phase structure,microstructure,and corresponding electrochemical performance of LiFePO_(4) batteries was studied.The results showed that Ag doped LiFePO_(4) had an olivine like structure with rod-shaped small particles,with a length of approximately 350-500 nm and a width of approximately 100 nm.There was slight agglomeration between the particles.The charge and discharge efficiency of LiFePO_(4) cathode materials doped with different molar ratios of Ag exceeds 95%.The appropriate doping of Ag molar ratios improved the cycling stability,initial discharge specific capacity,and capacity retention of LiFePO_(4).As the molar ratio of Ag doping increased,the maximum discharge specific capacity of LiFePO_(4) first increased and then decreased.The discharge specific capacity of LiFePO_(4) with a 3%Ag molar ratio reached its maximum value of 123.4 mAh/g.After 30 cycles,the maximum discharge specific capacity was 70.4 mAh/g,and the capacity retention rate was 57.05%.The corresponding charge transfer resistance was 632.7Ω.It can be seen that the comprehensive performance of 3%Ag LiFePO_(4) is the best.

关 键 词：锂离子电池 正极材料 LiFePO_(4) AG掺杂 电化学性能 

分 类 号：TM912.9[电气工程—电力电子与电力传动]