黄铁矿作为锂电池正极材料的电化学性能  

Electrochemical Properties of Pyrite as Lithium Battery Cathode Materials

作　　者：王大刚[1] 范力仁[1] 王圣平[1] 范畴[2] 何明中[1] 栗海峰[1] 

机构地区：[1]中国地质大学教育部纳米矿物材料及应用工程研究中心,武汉430074 [2]中南民族大学催化材料科学湖北省重点实验室,武汉430074

出　　处：《材料导报》2012年第18期93-96,共4页Materials Reports

基　　金：催化材料科学湖北省重点实验室开放基金(CHCL06008)

摘　　要：对天然黄铁矿进行深加工后获得平均粒径为13μm,w(Fe)、w(S)分别为45.30%、50.95%的超微细黄铁矿粉,并以高级脂肪酸盐对其进行改性,采用TG/DSC、XPS及XRD对粉体进行了表征。XRD和TG/DSC分析表明粉体主要物相为黄铁矿FeS2,表面包覆着有机改性剂;XPS分析结果表明,改性前后黄铁矿表面S分别以SO42-和[S2]2-形式存在,而Fe均以Fe3+形式存在。对粉体试样进行电化学阻抗谱、恒电流放电测试和循环伏安测试,结果表明,改性黄铁矿具有较小的电荷转移电阻和较好的导电性;常温下以0.354A电流放电,截止电压为0.5V,改性黄铁矿的放电电位平台为1.44V,放电比容量达850mAh/g,接近理论容量890mAh/g。Ultrafine pyrite powder was prepared from natural pyrite via deep processing, including gravity sepa- ration,floatation and airflow grind. The content of Fe and S are 45.30wt% and 50. 95wt% respectively, and the ave- rage grain size is 13μm Ultrafine pyrite powder was modified by senior fatty acid salt and investigated by TG/DSC, XRD and XPS. TG/DSC and XRD indicate the phase of mineral powder is mostly pyrite FeSe coated with organic modi- fier. XPS shows S on the pyrite surface before and after modification exists in the form of 8042- and [S2]^2- respec- tively, and Fe in Fe^3＋. Meanwhile, electrochemical impedance spectroscopy, cyclic voltammetry measurement and galvanostatic current charge and discharge method were applied to exhibit the electrochemical performance of pyrite. The results show that modified pyrite has lower charge transfer resistance and higher conductivity. The specific dis- charge capacity of modified pyrite is as high as 850mAh/g under 0. 354A current at room temperature and 0. 5V cutoff voltage, closing to the theoretical specific capacity of pyrite （890mAh/g）, and the voltage plateau is 1.44V,

关 键 词：黄铁矿 锂电池 正极材料 电化学性能 

分 类 号：TB39[一般工业技术—材料科学与工程] TD985[矿业工程—选矿]