Development of Skutterudite Thermoelectric Materials and Modules

Multifilling with La, Ba, Ga, and Ti in -type skutterudite and Yb, Ca, Al, Ga, and In in -type skutterudite remarkably reduces their thermal conductivity, resulting in enhancement of their dimensionless figure of merit to = 0.75 for -type (La,Ba,Ga,Ti)(1)(Fe,Co)(4)Sb-12 and = 1.0 for -type (Yb,Ca,Al,Ga,In)(0.7)(Co,Fe)(4)Sb-12. A thermoelectric module technology suitable for these skutterudites including diffusion barrier and electrode materials has been established. The diffusion barrier materials allow the electrode to coexist stably with the / skutterudites in the module's working temperature range of room temperature to 600A degrees C. Under conditions of hot/cold-side temperatures of 600A degrees C/50A degrees C, a skutterudite module with size of 50 mm x 50 mm x 7.6 mm exhibited generation performance of 32 W power output and 8% thermoelectric conversion efficiency.