聚对苯撑纳米复合提升ZnO基热电材料性能

PPP Addition to Improve Thermoelectric Properties of ZnO-based Thermoelectric Composites

以溶胶–凝胶法合成了PPP@Zn_(1-x)Co_xO纳米复合热电材料(x=0,0.025),再以放电等离子烧结制备成块体,并对其热电性能进行了研究。由透射电镜照片发现,PPP纳米颗粒尺寸在200 nm以下。热电性能分析表明,随着PPP添加量的增加,赛贝克系数先增大后减小。电导率随PPP含量增加而大幅度提高。与ZnO块体材料相比,溶胶–凝胶法合成的PPP@Zn_(1-x)Co_xO纳米复合热电材料的热导率大幅度降低,在640 K时,9wt%PPP的纳米复合热电材料热导率降低至5.4 W/(m·K)。电导率的增加和热导率的降低,导致热电性能大幅度提高,9wt%PPP@Zn_(0.975)Co_(0.025)O纳米复合热电材料在870 K时具有最大ZT值(0.16),是Zn_(0.975)Co_(0.025)O材料的8倍。

PPP@Zn1-xCoxO （x=0, 0.025） nanocomposites were prepared by Sol-Gel method, then bulk samples were prepared by spark plasma sintering. And thermoelectric properties of the samples were studied. Transmission electron microscopy （TEM） observations indicate that PPP nanoparticles are smaller than 200 nm. With the increase of PPP content, Seebeck coefficient gradually increases at first and then decreases, while electric conductivity increases quickly. Compared with ZnO bulk samples, the thermal conductivity of PPP@ Zn1-xCoxO nanocomposite is decreased. The thermal conductivity of 9wt% PPP@Zn0.975Co0.0250 is decreased to 5.4 W/（m.K） at 640 K. The increase of electrical conductivity and the decrease of thermal conductivity resulted in a great increase in the value of thermoelectric properties. 9wt% PPP@Zn0.975Co0.025O has a maximal ZT value of 0.16 at 870 K, which is 8 times of that of Zn0.975Co0.025o bulk material.