In a fast ion-conductor Cu₂Se, phase instability and the loss of Cu under operational conditions are the major impediments to its thermoelectric applications. Herein, a fast and low-cost pulse electric current method is developed to rapidly synthesize Cu₂Se-based materials with high thermoelectric performance. The Cu₂Se microstructures under an external current and high temperature close to the real working conditions have been investigated by both ex situ and in situ transmission electron microscopy. Due to the presence of Bi interstitials, dynamic Cu-ion fluctuation zones on the nanometer scale have been stabilized through the pinning effect of dislocations and the action of interfacial/boundary phases steric hindrance, both preventing Cu ions from escaping from the lattice. The hierarchical structure spanning from interstitial atoms to nanometer-scale precipitates, created by the pulse electric current method, forms a network of ion-blocking but electrically conducting barriers that greatly improve the stability of Cu₂Se-based thermoelectric materials.

在快速离子导体Cu ₂ Se中，相不稳定和工作条件下Cu的损失是其热电应用的主要障碍。在本文中，开发了快速且低成本的脉冲电流方法以快速合成具有高热电性能的Cu ₂ Se基材料。异位和原位研究了外部电流和高温下接近实际工作条件的Cu ₂ Se的微观结构。透射电子显微镜。由于Bi间隙的存在，通过位错的钉扎效应和界面/边界相空间位阻的作用，稳定了纳米级的动态Cu离子波动区，都防止了Cu离子从晶格逸出。通过脉冲电流方法创建的从间隙原子到纳米级沉淀物的分层结构形成了离子阻挡但导电的屏障网络，该屏障极大地提高了基于Cu ₂ Se的热电材料的稳定性。