服役热电器件界面损伤演化的热-电-力-化学耦合行为及寿命预测

热电器件能利用温差发电，且具有结构简单、无噪音、无机械振动和无需维护等优点，在航天航空、交通运输、生物器件等领域有着广阔的应用前景。然而，在热电器件的服役过程中，其热电材料与连接金属的界面失效问题十分突出，导致器件使用寿命大幅降低，成为制约其进一步发展的关键瓶颈。由于服役热电器件界面受到电迁移、热迁移、热变形、界面扩散和化学反应等因素的耦合作用，其界面失效机理十分复杂，建立界面失效理论和预测器件服役寿命非常具有挑战性。为了进一步拓展热电器件的工程应用，本项目实时评估服役热电器件的性能退化并定时表征界面三维形貌演化，揭示其界面失效机理，建立界面热-电-力-化学耦合失效理论，给出器件的服役寿命预测模型，并提出热电器件耐久性优化设计方法。本项目属于前沿的基础研究，具有较强挑战性，其研究成果将对高耐久性热电器件的设计和优化提供理论基础和技术储备，同时丰富和发展热-电-力-化学多场耦合力学理论。

Thermoelectric generators (TEGs) can directly convert heat flux into electrical energy, and possess the advantages of structural simplicity, noiseless, no mechanical vibration, and maintenance-free, leading to wide engineering applications such as aerospace, transportation, and biological devices. However, the problem of interface failure between thermoelectric materials and electrodes has always been quite outstanding for in-service TEGs, causing a great reduction in its service life and restricting its further development. The interface of working TEGs usually subject to the combined effects of electromigration, thermal conduction, thermal deformation, interfacial diffusion, and chemical reactions, which makes the analysis of the interface failure problems very challenging. To further broaden the applications of TEGs, this project assess the real-time performance degradation and characterize the 3D interface evolution of in-service TEG, aims to i) revealing the interface failure mechanism, ii) establishing the thermo-electro-mechano-chemical coupling theory of interface failure, iii) developing the lifetime prediction model, and iv) proposing the device optimization method of TEGs. This project is cutting-edge basic research with strong challenges. The research results will enrich and develop the theory of thermo-electro-mechano-chemical multi-field coupling mechanics. Furthermore, it will provide a theoretical foundation and technical reserves for the design and optimization of high-endurance thermoelectric devices.