The engineering applications of thermoelectric (TE) devices require TE materials possessing high TE performance and robust mechanical properties. Research on thermal and electrical transport properties of TE materials has made significant progress during the last two decades, developing TE materials on the threshold of commercial applications. However, research on mechanical strength and toughness has lagged behind, restricting application of TE materials. Mechanical failure in these materials involves multi-scale processes spanning from atomistic scale to macro scale. We have proposed an integral stress-displacement method to estimate fracture toughness from intrinsic mechanical behavior. In this review, we summarize our recent progress on fracture toughness of TE materials. This is in three parts:

(1) Predicting fracture toughness of TE materials from intrinsic mechanical behavior;

(2) Intrinsic mechanical behavior and underlying failure mechanism of TE materials; and

(3) Nanotwin and nanocomposite strategies for enhancing the mechanical strength and fracture toughness of TE materials.

These findings provide essential comprehensive understanding of fracture behavior from micro to the macro scale, laying the foundation for developing reliable TE devices for engineering applications.

热电（TE）装置的工程应用要求TE材料具有高TE性能和强大的机械性能。在过去的二十年中，TE材料的热和电传输性能研究取得了重大进展，在商业应用的门槛下开发了TE材料。但是，有关机械强度和韧性的研究落后，限制了TE材料的应用。这些材料的机械故障涉及从原子尺度到宏观尺度的多尺度过程。我们提出了一种整体应力位移方法，以根据固有力学行为估算断裂韧性。在这篇综述中，我们总结了我们在TE材料断裂韧性方面的最新进展。这分为三个部分：

（1）根据内在的力学行为预测TE材料的断裂韧性；

（2）TE材料的内在力学行为和潜在破坏机理；和

（3）纳米孪生和纳米复合材料策略，以提高TE材料的机械强度和断裂韧性。

这些发现为从微​​观到宏观的断裂行为提供了必不可少的全面理解，为开发用于工程应用的可靠TE设备奠定了基础。