Improved Thermoelectric Performance Achieved by Regulating Heterogeneous Phase in Half-Heusler TiNiSn-Based Materials
Improved Thermoelectric Performance Achieved by Regulating Heterogeneous Phase in Half-Heusler TiNiSn-Based Materials
复制标题
通过调节 Half-Heusler TiNiSn 基材料的异相来提高热电性能
DOI：
10.1007/s11664-017-6013-8
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发表时间：
2018-06-01
影响因子：
2.1
通讯作者：
Shu, Mingzheng
中科院分区：
文献类型：
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作者：
Chen, Jun-Liang;Liu, Chengyan;Shu, Mingzheng
tinni基半赫斯勒（HH）合金具有优异的高温稳定性（高达1000 K）和热电应用的良好电学性能，有望成为在700 K至900 K温度范围内回收废热的热电材料。然而，它们的导热系数总是相对较高（5-10 W/mK），这使得它们的热电性能系数（ZT）难以进一步提高。在过去的十年中，在HH合金基体中引入纳米级二次相已被证明是优化TiNiSn热电性能的可行方法。在本研究中，通过简单的固相反应成功合成了一系列tinisn基合金。通过精确调控非均相（tin2sn和Sn）的含量和组成，成功地将热导率从4.9 Wm(-1) K-1降低到3.0 Wm(-1) K-1 （750 K）。因此，我们的tinins基热电材料在750 K时达到了0.49的ZT值。此外，通过减少Sn物质相，TiNiSn合金的热稳定性得到提高。
With excellent high-temperature stability (up to 1000 K) and favorable electrical properties for thermoelectric application, TiNiSn-based half-Heusler (HH) alloys are expected to be promising thermoelectric materials for the recovery of waste heat in the temperature ranging from 700 K to 900 K. However, their thermal conductivity is always relatively high (5-10 W/mK), making it difficult to further enhance their thermoelectric figure-of-merit (ZT). In the past decade, introducing nano-scale secondary phases into the HH alloy matrix has been proven to be feasible for optimizing the thermoelectric performance of TiNiSn. In this study, a series of TiNiSn-based alloys have been successfully synthesized by a simple solid-state reaction. The content and composition of the heterogeneous phase (TiNi2Sn and Sn) is accurately regulated and, as a result, the thermal conductivity successfully reduced from 4.9 W m(-1) K-1 to 3.0 Wm(-1) K-1 (750 K) due to multi-scale phonon scattering. Consequently, a ZT value of 0.49 is achieved at 750 K in our TiNiSn-based thermoelectric materials. Furthermore, the thermal stability of TiNiSn alloys is enhanced through reducing the Sn substance phase.