摘要
为降低锂离子电池正极材料磷酸铁锂(LiFePO_(4))的生产成本,探索选择合适的肥料级磷酸铵为磷源制备LiFePO_(4)正极材料。分别以分析纯NH_(4)H_(2)PO_(4)和(NH_(4))_(2)HPO_(4)为不同磷源,采用原位聚合-共沉淀法制备FePO_(4)前驱体,碳热还原法制备LiFePO_(4)/C。通过XRD、SEM、FTIR、氮气吸脱附测试等表征方法和电化学测试手段对所制备的LiFePO_(4)/C进行性质和性能研究。结果表明,以NH_(4)H_(2)PO_(4)为磷源制备的LiFePO_(4)/C材料具有较好的电化学性能和较高的振实密度,在0.1C下的首次放电比容量为150.86mAh/g,不同倍率下的放电比容量分别为150.86(0.1C)、146.20(0.2C)、138.93(0.5C)、130.35(1C)、118.83(2C)、101.48(5C)mAh/g,振实密度为1.02g/cm^(3)。因此,NH_(4)H_(2)PO_(4)更适合作为磷源制备LiFePO_(4)正极材料。以肥料级NH_(4)H_(2)PO_(4)为磷源制备了LiFePO_(4)/C,其首次放电比容量为82.60mAh/g,经初步除杂后首次放电比容量为130.63mAh/g。
In order to reduce the production cost of lithium iron phosphate (Li Fe PO_(4)) cathode material for lithium ion batteries,appropriate fertilizer-grade ammonium phosphate was selected as the phosphorus source to prepare Li Fe PO_(4) cathode material.Firstly,using analytically pure NH_(4)H_(2)PO_(4) and (NH_(4))_(2)HPO_(4) as different phosphorus sources,Fe PO_(4) precursor was prepared by in-situ polymerization-coprecipitation method,and Li Fe PO_(4)/C was prepared by carbothermal reduction method.The properties and performance of the prepared Li Fe PO_(4)/C were studied by XRD,SEM,FTIR,nitrogen adsorptiondesorption test and electrochemical test.The results showed that the Li Fe PO_(4)/C material prepared with NH_(4)H_(2)PO_(4) as the phosphorus source has better electrochemical performance and higher tap density.The initial discharge specific capacity at 0.1 C is 150.86 m Ah/g.The discharge specific capacities at different rates were 150.86 (0.1 C),146.20 (0.2 C),138.93 (0.5 C),130.35 (1 C),118.83 (2 C),101.48 (5 C) m Ah/g,respectively,and the tap density was 1.02 g/cm^(3).Therefore,NH_(4)H_(2)PO_(4) is more suitable as a phosphorus source to prepare Li Fe PO_(4) cathode material.The initial discharge specific capacity of Li Fe PO_(4)/C prepared with fertilizer grade NH_(4)H_(2)PO_(4) as phosphorus source is 82.60 m Ah/g,and after preliminary removal of impurities the initial discharge specific capacity reaches 130.63 mAh/g.
作者
李颖
薛开心
王红强
闫循帅
李彩虹
LI ying;XUE Kaixin;WANG Hongqiang;YAN Xunshuai;LI Caihong(School of Chemical Engineering,Inner Mongolia University of Technology,Hohhot 010051,China;Cangzhou Caike Lithium Energy Co.,Ltd.,Cangzhou,Hebei 061600,China;Guangdong Bangpu Recycling Technology Co.,Ltd.,Foshan,Guangdong 528137,China)
出处
《内蒙古工业大学学报（自然科学版）》
2024年第6期526-534,共9页
Journal of Inner Mongolia University of Technology：Natural Science Edition
基金
内蒙古自治区自然科学基金项目(2021MS05031)
内蒙古自治区高等学校2024生态安全研究专项(STAQZX202323)
内蒙古自治区直属高校基本科研业务费项目(JY20220362)。
关键词
磷酸二氢铵
磷酸氢二铵
磷酸铁锂
正极材料
ammonium dihydrogen phosphate
diammonium hydrogen phosphate
lithium iron phosphate
cathode material
作者简介
第一作者:李颖(1999-),女,2021级硕士研究生,主要从事锂离子电池正极材料研究。E-mail:1223303200@qq.com;通信作者:李彩虹(1967-),女,博士,教授,主要从事锂离子电池正极材料的合成及其性能研究。E-mail:licaihong616lch@163.com。
