Thermoelectric Power Generation from Lanthanum Strontium Titanium Oxide at Room Temperature through the Addition of Graphene

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• 作者：Yue Lin ; Colin Norman ; Deepanshu Srivastava ; Feridoon Azough ; Li Wang ; Mark Robbins ; Kevin Simpson ; Robert Freer ; Ian A. Kinloch
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：July 29, 2015
• 年：2015
• 卷：7
• 期：29
• 页码：15898-15908
• 全文大小：812K
• ISSN：1944-8252

文摘

The applications of strontium titanium oxide based thermoelectric materials are currently limited by their high operating temperatures of >700 掳C. Herein, we show that the thermal operating window of lanthanum strontium titanium oxide (LSTO) can be reduced to room temperature by the addition of a small amount of graphene. This increase in operating performance will enable future applications such as generators in vehicles and other sectors. The LSTO composites incorporated one percent or less of graphene and were sintered under an argon/hydrogen atmosphere. The resultant materials were reduced and possessed a multiphase structure with nanosized grains. The thermal conductivity of the nanocomposites decreased upon the addition of graphene, whereas the electrical conductivity and power factor both increased significantly. These factors, together with a moderate Seebeck coefficient, meant that a high power factor of 鈭?500 渭Wm^鈥?聽K^鈥? was reached at room temperature at a loading of 0.6 wt % graphene. The highest thermoelectric figure of merit (ZT) was achieved when 0.6 wt % graphene was added (ZT = 0.42 at room temperature and 0.36 at 750 掳C), with >280% enhancement compared to that of pure LSTO. A preliminary 7-couple device was produced using bismuth strontium cobalt oxide/graphene-LSTO pucks. This device had a Seebeck coefficient of 鈭?500 渭V/K and an open voltage of 600 mV at a mean temperature of 219 掳C.