Nanostructure Approach Enhancing the Thermoelectric Performance of a p-Type HMS-CrSi2 Composite Synthesized by the MS-SPS Technique

Significant variations in figure-of-merit (zT) values between n and p-type silicides impede the thermoelectric performance of cost-effective silicide-based thermoelectric power generators (TEGs). We report a significantly enhanced and compatible zT value in a p-type higher manganese silicide (HMS)-CrSi2 nanocomposite synthesized using a combination of liquid-phase melt-spinning (MS) and solid-phase spark plasma sintering (SPS). The MS-SPS-processed HMS-CrSi2 (80-20 wt %) composite material shows substantially enhanced electrical conductivity and a high power factor value. Also, a remarkable enhancement of the HMS-20 wt % CrSi2 composite materials' zT similar or equal to 0.92 is realized due to a concurrent reduction in its thermal conductivity (kappa). This 2-fold increase in the zT value compared to pure HMS exhibited by the composite material, consisting of nanoscale dimensional grain features, mainly originates from a rapid solidification melt-spinning process. The composite of HMS-CrSi2 synthesized using the combination of MS and SPS techniques is investigated to realize a high thermoelectric figure-of-merit (zT) value in a p-type thermoelectric material, which is considered a potential compatible counterpart for n-type silicides.

Automated summary

In this study, a p-type higher manganese silicide (HMS)-CrSi2 nanocomposite with significantly enhanced and compatible thermoelectric performance was synthesized using a combination of liquid-phase melt-spinning and solid-phase spark plasma sintering. The composite material showed a 2-fold increase in the thermoelectric figure-of-merit (zT) value compared to pure HMS, mainly due to a reduction in thermal conductivity.