Decoupling Thermoelectric Performance and Stability in Liquid-Like Thermoelectric Materials
Decoupling Thermoelectric Performance and Stability in Liquid-Like Thermoelectric Materials
复制标题
类液热电材料的热电性能和稳定性的解耦
DOI：
10.1002/advs.201901598
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发表时间：
2020
期刊：
影响因子：
15.1
通讯作者：
Chen Lidong
中科院分区：
文献类型：
--
作者：
Mao Tao;Qiu Pengfei;Hu Ping;Du Xiaolong;Zhao Kunpeng;Wei Tian-Ran;Xiao Jie;Shi Xun;Chen Lidong
类液体热电材料是近年来发现的一类有前途的热电材料，由于其热电优值（zT）的范围宽，成本低，并且环境友好。然而，在大电流和/或温度梯度下，Cu/Ag金属沉积的低工作稳定性极大地限制了它们的实际应用。对于类液体材料，既需要高的zT以获得高效率，又需要大的临界电压以获得良好的稳定性，但它们通常是强相关的，并且难以单独调谐。在此，基于热力学分析，它表明，这种相关性可以通过掺杂不动离子到类液体的子晶格去耦。以Cu 2-δ S为例，在Cu 1.90 S中掺杂固定的Fe离子几乎没有降低初始大临界电压，但通过将载流子浓度调节到最佳范围，在1000 K下将zT显著提高到1.5。这些Fe掺杂的Cu 2-δ S基化合物结合了低成本和环境友好的特点，在民用领域显示出巨大的应用潜力。这项研究揭示了实现良好的稳定性和高性能的许多其他液体状热电材料，没有考虑到真实的应用之前。
Liquid-like materials are one family of promising thermoelectric materials discovered in the past years due to their advantanges of ultrahigh thermoelectric figure of merit (zT), low cost, and environmental friendliness. However, their practial applications are greatly limited by the low service stability from the Cu/Ag metal deposition under large current and/or temperature gradient. Both high zT for high efficiency and large critical voltage for good stability are required for liquid-like materials, but they are usually strongly correlated and hard to be tuned individually. Herein, based on the thermodynamic analysis, it is shown that such a correlation can be decoupled through doping immobile ions into the liquid-like sublattice. Taking Cu2-delta S as an example, doping immobile Fe ions in Cu1.90S scarcely degrades the initial large critical voltage, but significantly enhances the zT to 1.5 at 1000 K by tuning the carrier concentration to the optimal range. Combining the low-cost and environmentally friendly features, these Fe-doped Cu2-delta S-based compounds show great potential in civil applications. This study sheds light on the realization of both good stability and high performance for many other liquid-like thermoelectric materials that have not been considered for real applications before.