The Soret effect results in a concentration gradient when a mixture is exposed to a temperature gradient. It is a balance between diffusion of mass driven by the temperature gradient (thermal diffusion) and mass diffusion acting to remove the concentration gradient. Thus, the Soret effect is measured at steady state. In this work, the Soret effect was studied in a thermogalvanic cell with lithium metal electrodes and a dry polymer electrolyte composed of poly(ethylene oxide) and lithium bis-trifluoromethanesulfonylimide (LiTFSI). The concentration gradient was determined by measuring the voltage of the thermogalvanic cell. This was examined at several different temperature gradients and with four different salt concentrations. The Soret coefficient was found to be similar to that observed in small-molecule mixtures and electrolytes and significantly less than polymeric systems. An explanation for this unexpected result is proffered. The Soret coefficient was found to be concentration dependent, which requires further investigation. Finally, it was demonstrated that the thermogalvanic cells used to measure the Soret coefficient can also be used to generate power. Thus, polymer electrolytes are potentially of interest for waste heat recovery, and thermal diffusion might be used to improve battery efficiency.

中文翻译：

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干聚合物电解质中的Soret效应

当混合物暴露于温度梯度时，Soret效应会导致浓度梯度。它是由温度梯度驱动的质量扩散（热扩散）与起到消除浓度梯度作用的质量扩散之间的平衡。因此，在稳态下测量了索雷特效应。在这项工作中，在具有锂金属电极和由聚环氧乙烷和双三氟甲烷磺酰亚胺锂（LiTFSI）组成的干聚合物电解质的热原电池中研究了索雷特效应。通过测量热原电池的电压来确定浓度梯度。在几种不同的温度梯度和四种不同的盐浓度下对此进行了检查。发现Soret系数与在小分子混合物和电解质中观察到的相似，并且显着小于聚合物体系。提供对此意外结果的解释。发现Soret系数与浓度有关，这需要进一步研究。最后，证明了用于测量Soret系数的热原电池也可以用于发电。因此，聚合物电解质可能对于废热回收是令人感兴趣的，并且热扩散可以用于提高电池效率。结果表明，用于测量Soret系数的热原电池也可以用于发电。因此，聚合物电解质可能对于废热回收是令人感兴趣的，并且热扩散可以用于提高电池效率。结果表明，用于测量Soret系数的热原电池也可以用于发电。因此，聚合物电解质可能对于废热回收是令人感兴趣的，并且热扩散可以用于提高电池效率。