固相反应制备Li_(2)FeSiO_(4)/C及嵌/脱锂性能研究  

Synthesis of Li_(2)FeSiO_(4)/C by Solid-State Reaction and Its Lithium Intercalation/de-Intercalation Property

作　　者：李付绍 徐应仙 武青青 邓明森[1] LI Fushao;XU Yingxian;WU Qingqing;DENG Mingsen(Guizhou Provincial Key Laboratory of Computational Nano-Material Science(Guizhou Education University),Guiyang Guizhou 550018,China)

机构地区：[1]贵州省纳米材料模拟与计算重点实验室(贵州师范学院),贵州贵阳550018

出　　处：《广西师范大学学报（自然科学版）》2022年第6期154-162,共9页Journal of Guangxi Normal University:Natural Science Edition

基　　金：国家自然科学基金(52062006);贵州省基础研究计划(黔科合基础-ZK[2021]一般237)。

摘　　要：本文利用直接高温固相反应,合成制备了锂离子电池正极材料Li_(2)FeSiO_(4)及Li_(2)FeSiO_(4)/C,并研究了碳复合改性对Li_(2)FeSiO_(4)的结构、电导率、嵌/脱锂性能、循环比容量等方面的影响。结果表明,材料的制备工艺流程简单易行,有利于规模化生产;碳复合改性有利于提高硅酸盐正极材料的导电性能,改善材料在成相反应后的粒度分布;特别是碳复合改性有利于提高Li_(2)FeSiO_(4)的嵌/脱锂性能和循环比容量,Li_(2)FeSiO_(4)/C在0.1C倍率下首次放电容量高达120 mAh/g以上,大大高于未经复合改性Li_(2)FeSiO_(4)的20 mAh/g。研究表明,Li_(2)FeSiO_(4)是一种很有研究价值和开发潜力的锂离子电池正极材料,碳复合改性可显著克服该材料在电导率、电化学性能等诸多方面所存在的不足和局限。In this paper,Li_(2)FeSiO_(4) as well as Li_(2)FeSiO_(4)/C was prepared as cathode materials of lithium-ion batteries by direct high temperature solid-sate reaction,and effect of carbonized modification on the structure,electrical conductivity,lithium intercalation/de-intercalation property,and cyclic specific capacity of Li_(2)FeSiO_(4) was investigated.The result shows that this process of material preparation is economic and scalable.The carbonized composite helps to enhance the electrical conductivity of Li_(2)FeSiO_(4),and also improves the particle distribution after phase formation reaction of Li_(2)FeSiO_(4).Most importantly,carbonized composite quite facilitates the lithium intercalation/de-intercalation and greatly promotes the cyclic specific capacity of Li_(2)FeSiO_(4),and initial discharge capacity of Li_(2)FeSiO_(4)/C under rate of 0.1C reaches above 120 mAh/g,much higher than the 20 mAh/g of Li_(2)FeSiO_(4).In conclusion,Li_(2)FeSiO_(4) is a most promising cathode material of lithium-ion batteries,and carbonized modification can overcome the shortcomings of this cathode material in aspects of electrical conductivity,electrochemical performance,and so on.

关 键 词：锂离子电池 硅酸盐 正极材料 嵌/脱锂性能 电化学技术 

分 类 号：TM911[电气工程—电力电子与电力传动]