超高压处理前驱体对LiFePO_4/C性能的影响  

Effect of ultrahigh-pressure treatment precursor on performance of LiFePO_4/C

作　　者：王力臻[1,2] 江庆 高可政[1] 方华[1] 

机构地区：[1]郑州轻工业学院材料与化学工程学院,河南郑州450002 [2]河南省表界面科学重点实验室,河南郑州450002

出　　处：《电池》2017年第4期193-195,共3页Battery Bimonthly

基　　金：国家自然科学基金面上项目子课题(21471135)

摘　　要：通过超高压处理溶胶-凝胶前驱体,以高温固相法制备磷酸铁锂(LiFePO_4)/C。用恒流充放电、循环伏安和交流阻抗等方法研究产物的电化学性能,并进行XRD、SEM等分析。超高压处理并没有改变LiFePO_4材料的晶体结构和充放电反应机理。与未经超高压处理的前驱体相比,超高压预处理的前驱体制备的材料粒径减小,均匀性提高,0.1 C首次放电容量达148.47 mAh/g、在平台电压范围内的放电容量增加约16.3 mAh/g,经过不同倍率共40次循环,容量保持率达98.2%,且倍率放电性能得到提高,欧姆阻抗和电化学反应阻抗减小。After a ultrahigh-pressure treating to the precursor prepared by sol-gel method,lithium iron phosphate（ LiFePO_4）/C was prepared by high temperature solid state method. The electrochemical performance of product was studied by galvanostatic charge/discharge test,cyclic voltammetry and A. C. impedance. The structural and morphology were analyzed by XRD and SEM. Ultrahighpressure treatment did not change the crystal structure and charge-discharge reaction mechanism of LiFePO_4. The particle size of target material prepared by ultrahigh-pressure treatment precursor was decreased and particle uniformity improved compared with the precursor without ultrahigh-pressure treatment. The initial specific capacity reached 148. 47 mAh/g at rate of 0. 1 C,increased by 16. 3 mAh/g at the range of platform voltage. After 40 cycles at different rates,the capacity retention rate was 98. 2% and rate capability improved. Ohmic resistance and electrochemical reaction impedance decreased.

关 键 词：锂离子电池 正极材料 磷酸铁锂(LiFePO4) 超高压处理 

分 类 号：TM912[电气工程—电力电子与电力传动]