Thermoelectric performance of Ni compensated cerium and neodymium double filled p-type skutterudites
Abstract
We have synthesized Ni compensated Ce and Nd double filled p-type skutterudites CexNdxFe3.7Ni0.3Sb12 with x = 0.35, 0.40, 0.45, and 0.5 by a melting–quenching–annealing method. The samples were made by directly hot pressing the hand ground powder at 650 °C for 5 minutes at a pressure of about 80 MPa. Since Ni has two more electrons than Fe, a lower power factor and a stronger bipolar effect in thermal conductivity are expected at higher temperature. In the experiments, we have demonstrated that by suitably tuning the Fe–Ni ratio and filler concentration, we can achieve both a higher power factor (∼35 μW cm−1 K−2 at 535 °C) and a lower thermal conductivity (∼2.1 W m−1 K−1 at room temperature and ∼2.7 W m−1 K−1 at 535 °C) in Ce0.4Nd0.4Fe3.7Ni0.3Sb12. A peak thermoelectric figure-of-merit of ∼1.1 at 475 °C is achieved in Ce0.4Nd0.4Fe3.7Ni0.3Sb12.