气氛对钼酸铵分解的影响及产物的电化学性能  

Effect of different atmosphere on decomposition products of ammonium molybdate

作　　者：许占位[1] 王天[1] 刘鑫悦 段欣彤 杜钊[1] 王盈[1] 

机构地区：[1]陕西科技大学材料科学与工程学院,陕西西安710021

出　　处：《陕西科技大学学报》2017年第3期53-58,共6页Journal of Shaanxi University of Science & Technology

基　　金：西北工业大学凝固技术国家重点实验室开放基金项目(SKLSP201617);陕西科技大学引进省部级重点学科带头人科研启动基金项目(BJ15-01);陕西科技大学学术团队计划项目(XSD1445)

摘　　要：研究了气氛对钼酸铵分解的影响及其产物的电化学性能.首先对钼酸铵((NH_4)_6Mo_7O_(24)·4H_2O)在高流速氩气条件下进行热重测试(TGA),分析钼酸铵的热解过程.采用固相法制备产物,研究了钼酸铵热解生成的NH_3与MoO_3等发生氧化还原反应对最终结果的影响.利用X射线衍射分析(XRD)、能谱分析(EDS)、扫描电子显微镜(SEM)等对产物的物相及形貌进行表征.结果表明,Ar气气体流量分别为150sccm、125sccm、50sccm时,产物依次为Mo_4O_(11)和少量MoO_3、Mo_4O_(11)和少量MoO_2、少量Mo_4O_(11)和MoO_2,随着Ar气气体体积流量减小到0sccm时得到纯相MoO_2.将所得MoO_2作为活性材料应用在钠离子电池负极上,采用充放电测试系统测试了其电化学性能,电流密度为50 mA·g^(-1)时连续循环12次后其首次放电比容量高达215mAh·g^(-1),在电流密度为100mA·g^(-1)、200mA·g^(-1)、500mA·g^(-1)时的放电比容量基本稳定在180mAh·g^(-1)、100mAh·g^(-1)、75mAh·g^(-1),表现出了较高的电化学性能.Ammonium molybdate was employed as the raw material,by controlling and chan-ging the flow rate of argon atmosphere to display the effect of molybdate pyrolWe tested the TGA of ammonium molybdate in high Ar gas flow rate,analyzing various de-composition products of ammonium molybdate. We employed solid state method fabricating products, studying the effect of redox reaction between NH3 and M0O3 on the final resutt. X- ray diffraction, Energy-dispersive spectrometer and Scanning electron microscope were used to characterize the crystal structure and morphology of the products. The low of argon at-mosphere on decomposition products of ammonium molybdate and the impact on the electro-chemical performance were explored respectively. At the same temperature, the results indi-cate that when the Ar gas flow rate was 150 seem, the products were MoO3 and Mo4O11 ,When the flow rate reduced to 125 seem, the products became a mixture of Mo0 3 ,Mo40 11 and a little Mo02. When the flow rate turned to 50 seem, the products became a MoO2 and a little Mo4011 ,respectively. Finally the flow rate became O sccm,MoO2 was ob-tained. We apply as-prepared MoO2 active materials to sodium-ion batteries, measuring the electrochemical performance using charge/discharge test system. MoO2 has an initial dis-charge capacity of 215 mAh·g^-1 at constant current density 50 mA·g^-1 after 12 cycles. The capacities of the obtained Mo02 were 180 mAh·g^-1,100 mAh ·g^-1 and 75 mAh ·g^-1 at the constant current density 100 mA·g^-1,200 mA·g^-1 and 500 mA·g^-1,respectively.

关 键 词：钼酸铵 二氧化钼 钠离子电池 负极材料 

分 类 号：TB383[一般工业技术—材料科学与工程]