Characterization and Performance of Cement-based Thermoelectric Materials
Characterization and Performance of Cement-based Thermoelectric Materials
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发表时间：
2020
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通讯作者：
R. Jani;N. Holmes;R. West;K. Gaughan;Xiaoli Liu;Esther Orisakwee;C. Johnston;M. Qu;J. Kohanoff;L. Stella;Hongxi Yin
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作者：
R. Jani;N. Holmes;R. West;K. Gaughan;Xiaoli Liu;Esther Orisakwee;C. Johnston;M. Qu;J. Kohanoff;L. Stella;Hongxi Yin
热电材料能将热能直接转化为电能。环境热能收集可能是将建筑物从能源消耗者转变为能源收集者的有效途径，从而使其更具可持续性。建筑内外墙之间存在相对稳定的温度梯度（储存能量），利用热电原理可以产生有意义的能量（即电能）。这最终将有助于降低建筑物的表面温度和能源消耗，尤其是在城市地区。本文介绍了正在进行的开发和表征水泥基热电材料的工作。样品是用水泥作为基材制造的，并加入不同的金属氧化物（Bi₂O₃和Fe₂O₃）来增强它们的热电性能。对制备的样品进行了一系列表征测试，以确定其塞贝克系数、电导率和导热系数。研究表明，加入添加剂的水泥浆体具有半导体范围内的物理性质，初始电阻率值较低，但随着时间的推移，电阻率值逐渐增大，从而导致其电导率降低。掺加添加剂的水泥浆体导热系数低于对照样品。在最初的一组测量中，塞贝克系数值是相对不稳定的，因为内部和外部环境需要保持在热稳定的条件下才能获得稳定的结果。详细的分析有助于确定和消除表征过程中的错误来源，并获得可重复的结果。这也导致了对水泥基热电材料性能有重大影响的参数的确定。
: Thermoelectric materials enable direct conversion of thermal energy to electricity. Ambient heat energy harvesting could be an effective route to convert buildings from being energy consumers to energy harvesters, thus making them more sustainable. There exists a relatively stable temperature gradient (storing energy) between the internal and external walls of buildings which can be utilized to generate meaningful energy (that is, electricity) using the thermoelectric principle. This could ultimately help reduce the surface temperatures and energy consumption of buildings, especially in urban areas. In this paper, ongoing work on developing and characterizing a cement-based thermoelectric material is presented. Samples are fabricated using cement as a base material and different metal oxides (Bi₂O₃ and Fe₂O₃) are added to enhance their thermoelectric properties. A series of characterization tests are undertaken on the prepared samples to determine their Seebeck coefficient, electrical and thermal conductivity. The study shows that cement paste with additives possesses physical properties in the range of semiconductors whereby, initially, the resistivity values are low but with time, they increase gradually, thus resulting in lower electrical conductivity. The thermal conductivity of the cement paste with additives is lower than the control sample. Seebeck coefficient values were found to be relatively unstable during the initial set of measurements because the internal and external environment needed to be kept in a thermally stable condition to achieve steady results. The detailed analysis helped determine and eliminate the source of errors in the characterization process and obtain repeatable results. It also led to the identification of the parameters having a significant impact on the properties of cement-based thermoelectric materials.