Na_(1.7)Co_2O_(4-x)F_x的制备及其热电性能  

Preparation and thermoelectric properties of Na_(1.7)Co_2O_(4-x)F_x powders

作　　者：仲洪海[1] 陈德方[1] 林逸榕[2] 管其刚[1] 李兴全[1] 蒋阳[1] 

机构地区：[1]合肥工业大学材料科学与工程学院,合肥230009 [2]合肥工业大学电气与自动化工程学院,合肥230009

出　　处：《中国科技论文》2012年第2期111-115,共5页China Sciencepaper

基　　金：中国博士后科学基金资助项目(20100470827);合肥工业大学博士后科学基金资助项目(103035037)

摘　　要：以Na2CO3、NaF、Co（NO3）2.6H2O和HNO3为原料,去离子水为溶剂,柠檬酸为螯合剂,采用自蔓延法制备了Na1.7Co2O4-xFx（x=0,0.05,0.1,0.15,0.2）粉体。粉末的X射线衍射分析表明,该方法能合成单一相的Na1.7Co2O4-xFx。粉体的粒度分布分析显示其粒度分布在11.505~50.508μm,平均粒径为28.543μm。烧结试样的扫描电镜照片显示F的掺杂能抑制晶粒的长大。在373~873K下,烧结体热电性能的测试结果显示,随着F的加入,烧结体试样的电导率与Seebeck系数均有提高,其中Na1.7Co2O3.85F0.15的烧结体在873 K时Seebeck系数和功率因子达到最大值分别为254μV.K 1和1.20×10 3W.m 1.K 2。Na1.7Co2O4-xFx （x-=0, 0.05, 0.1, 0.15, 0.2） polycrystalline samples were prepared by a simple self-propagation route with Na2CO3, NaF, Co（NO3）2·6H2O and HNO3 as raw materials, de-ionized water as a dissolvent, and citric acid as a chelating agent. The synthesized powders were analyzed by X-ray diffraction （XRD）. The microstructures of the sintered samples were observed by scanning electron microscopy （SEM）. The results indicated that there was a simple phase and no other phases generated in the powders. The grain size of the powders was from 11.505 μm to 50.508 μm, with an average grain size of 28.543μm. The doping F- could inhibit grain growth during the sintering process. The thermoelectric properties of Na1.7Co2O4-xFx were carefully studied from 373 K to 873 K. The results showed that the electrical conduction and Seebeck coefficient of Na1.7Co2O4-xFx samples increased with F- doping. The maximum Seebeck coefficient and power factor of Na1.7Co2O3.85F0.15 samples were 254 μV.K^-1 and 1.20× 10^-3 W.m^-1·K^-2 at 873 K, respectively.

关 键 词：功能材料 热电转换 自蔓延 烧结 掺杂 热电性能 

分 类 号：TB34[一般工业技术—材料科学与工程]