Na_1.4Co₂O₄基热电材料的溶胶-凝胶法制备及表征

来源期刊：金属学报2011年第1期

论文作者：厉英 马北越 王臻明 姜茂发

文章页码：109 - 114

关键词：热电材料； 钴酸盐； 热电性能； 掺杂； 溶胶-凝胶法

Key words：thermoelectric material； cobaltite； thermoelectric property； doping； sol-gel method

摘    要：采用溶胶-凝胶法制备了掺杂Sr,Li和Cu的Na_1.4Co₂O₄基热电材料,采用XRD分析了Na_1.4Co₂O₄基热电材料的相组成.通过DTA-TG曲线确定材料的预烧结和终烧结温度分别为450和850℃.研究了掺杂量对Na_1.4Co₂O₄基材料电阻率、Seebeck系数和功率因子等热电性能的影响.结果表明,掺杂Li可降低Na_1.4Co₂O₄的电阻率,掺杂Sr和Cu使材料的电阻率增加;掺杂Li和Cu可大幅度提高Na_1.4Co₂O₄的Seebeck系数和功率因子;掺杂Sr的改善效果不显著,掺杂Li的效果最好;当Li掺杂量为0.40,Na_1.4Co₂O₄基热电材料的功率因子在15℃时达到最大值7444.73μW.m^-1.K^-2.

Abstract: Sr, Li and Cu-doped Na_1.4Co₂O₄ based thermoelectric materials were prepared by sol-gel process. The phase constitution of Na_1.4Co₂O₄ based thermoelectric materials was analyzed by XRD. According to DTA-TG curves, the pre-sintering and sintering temperatures of the materials were obtained to be 450℃ and 850℃, respectively. The influences of doping amount on the electrical resistivity, Seebeck coefficient and power factor of Na_1.4Co₂O₄ based materials were investigated. The results showed that doping Li could decrease the electrical resistivity of Na_1.4Co₂O₄ doping Sr and Cu could increase the electrical resistivity. Doping Li and Cu could improve the Seebeck coefficient and power factor of Na_1.4Co₂O₄. The improving effect on Na_1.4Co₂O₄ by doping Sr is not remarkable but by doping Li is the best. When 0.40 Li was doped, the power factor of Na_1.0Li_0.4Co₂O₄ at 15℃reaches maximum value of 7444.73μW·m^-1·K^-2.