摘要
Thermoelectric semiconductors based on CoSb_(3)hold the best promise for recovering industrial or automotive waste heat because of their high efficiency and relatively abundant,lead-free constituent elements.However,higher efficiency is needed before thermoelectrics reach economic viability for widespread use.In this study,n-type In_(x)Ce_(y)Co_(4)Sb_(12+z)skutterudites with high thermoelectric performance are produced by combining several phonon scattering mechanisms in a panoscopic synthesis.Using melt spinning followed by spark plasma sintering(MS-SPS),bulk In_(x)Ce_(y)Co_(4)Sb_(12+z)alloys are formed with grain boundaries decorated with nano-phase of InSb.The skutterudite matrix has grains on a scale of 100-200 nm and the InSb nano-phase with a typical size of 5e15 nm is evenly dispersed at the grain boundaries of the skutterudite matrix.Coupled with the presence of defects on the Sb sublattice,this multi-scale nanometer structure is exceptionally effective in scattering phonons and,therefore,InxCey-Co_(4)Sb_(12)/InSb nano-composites have very low lattice thermal conductivity and high zT values reaching in excess of 1.5 at 800 K.
基金
H.L.,X.T.,and Q.Z.acknowledge financial supports of the National Basic Research Program of China(Grant No.2013CB632502)
Natural Science Foundation of China(Grant Nos.51402222,51172174,and 51002112)
the 111 Project of China(Grant No.B07040).U.A.and G.J.S.acknowledge funding from the Solid-State Solar-Thermal Energy Conversion Center(S3TEC),an Energy Frontier Research Center,funded by the U.S.Department of Energy,Office of Science,Basic Energy Sciences(DE-SC0001299).
