Thermoelectrics in ice slabs: charge dynamics and thermovoltages
Thermoelectrics in ice slabs: charge dynamics and thermovoltages
复制标题
冰板中的热电：电荷动力学和热电压
DOI：
10.1039/d1cp02304g
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发表时间：
2021
影响因子：
3.3
通讯作者：
Qiao, Rui
中科院分区：
文献类型：
--
作者：
Zhang, Hongwei;De Poorter, John;Mukherjee, Ranit;Boreyko, Jonathan B.;Qiao, Rui
冰的热电效应在许多自然现象和工程现象中起着重要作用。我们用数值和分析的方法研究了有限厚度的冰板在施加温差的情况下的通电现象。当暴露在温度梯度下时，热电作用包括一个由铋缺陷主导的快速初始阶段和随后由离子缺陷驱动的缓慢阶段。通过解析导出了第一阶段和第二阶段的时间尺度，它们分别对应于基于铋和离子缺陷密度的德拜时间尺度。对于一个给定的冰板，在稳定状态下，冰板上的热电压和两端电荷的积累很大程度上取决于冰板的厚度，热电压的敏感性更为明显。分析了热电压计算值与实验值之间的差异。分析表明，尽管冰中的热电效应在50年前就被发现了，但从缺陷的体积和界面特性到热电压的测量，在对这些效应的定量理解中存在着显著的差距。填补这些空白需要进一步的实验、理论和计算研究。
Thermoelectric effects of ice play an important role in many natural and engineering phenomena. We investigate, numerically and analytically, the electrification of finite-thickness ice slabs due to an imposed temperature difference across them. When exposed to a temperature gradient, thermoelectrification involves a fast initial stage dominated by Bjerrum defects and a subsequent slow stage driven by ionic defects. The time scales of the first and second stages are derived analytically and correspond to the Debye time scales based on the density of Bjerrum and ionic defects, respectively. For a given ice slab, at the steady state, the thermovoltage across it and the charge accumulation near its two ends depend strongly on its thickness, with the sensitivity of the thermovoltage being more pronounced. The discrepancy between the computed thermovoltage and experimental measurements is analyzed. The analysis shows that, although thermoelectric effects in ice were discovered 50 years ago, significant gaps, ranging from the bulk and interfacial properties of defects to the measurement of thermovoltage, exist in the quantitative understanding of these effects. Filling these gaps requires further experimental, theoretical, and computational studies.