Lattice distortion realizing the “treble-high” thermoelectric module

Abstract

Desirable diffusion barrier layers play a fatal role in achieving long-term high-temperature stable service for the skutterudites (SKDs)-based thermoelectric (TE) device. Consequently, we proposed a screening strategy for diffusion barrier layers based on the lattice distortion design, identifying the Fe₈₀V₂₀ alloy as a promising candidate barrier layer for p-type SKD materials. Theoretically, we found that the significant lattice distortion induced by the addition of V can lead to a higher activation energy barrier for Fe migration (155% higher than Cr addition). Experimentally, compared to Fe₈₀Cr₂₀ joints, the Fe₈₀V₂₀ joints exhibit outstanding interfacial reliability and stability. Eventually, we achieved a “treble-high” SKDs-based TE module, which possesses a record high conversion efficiency of 10.7% and a high-power density of 2.18 W·cm^-2 under a temperature difference of 585 K, and high long-term reliability. This work demonstrates a novel and effective strategy for screening diffusion barrier layers in TE devices, laying a solid foundation for their practical application in power generation.