Thermoelectric properties of BiSbTe/graphene nanocomposites

In this work, BiSbTe based graphene composites with different vol% of graphene were processed by the pressure assisted high frequency induction heated sintering. The exfoliated graphene was uniformly dispersed in the BiSbTe powder through magnetic stirring and ball milling. The pristine BiSbTe and composites powders were consolidated by the high frequency induction heated sintering. Thermoelectric properties of the developed bulks were investigated in the temperature range 300–500 K. The results suggest that ball milling as well as incorporation of graphene substantially changes the transport properties of nanostructured BiSbTe composites from pristine bulk. The electrical conductivity of the composites degraded somewhat gradually with the addition of graphene. The effective thermal conductivity reduces by incorporation of graphene, which is attributed to increased phonon scattering by the enormous nanostructured phase boundaries and graphene. The enhanced Seebeck coefficient accompanied by the reduction in thermal conductivity leads to improved figure of merit up to ~ 1.2 at ~ 375 K for 0.5 vol% graphene/BiSbTe composite.