Comparative Study of the Microstructure and Thermoelectric Properties of ZnSb Prepared via Different Synthesis Processes and Evaluated in Thermoelectric Modules

In this study, we investigate the effects of fabrication processes on the microstructure and thermoelectric performance of ZnSb mid-temperature thermoelectric materials.Among the examined routes, mechanical alloying combined with spark plasma sintering produces ZnSb with an ultrafine average grain size of ~10.7 nm, a markedly high relative density of >99%, and lower thermal conductivity, achieving a maximum figure of merit of approximately 1.0 at 600 K.In contrast, melting-based processes suffer from Zn volatilization and grain coarsening.Module testing and energy analysis further demonstrate that the optimized process enables practical thermoelectric performance, achieving a power density of 19.0 mW/cm 2 , with reduced energy consumption and carbon emissions.