High performance p-type segmented leg of misfit-layered cobaltite and half-Heusler alloy

In this study, a segmented p-type leg of doped misfit-layered cobaltite Ca_2.8Lu_0.15Ag_0.05Co₄O_9+δ and half-Heusler Ti_0.3Zr_0.35Hf_0.35CoSb_0.8Sn_0.2 alloy was fabricated and characterized. The thermoelectric properties of single components, segmented leg, and the electrical contact resistance of the joint part were measured as a function of temperature. The output power generation characteristics of segmented legs were characterized in air under various temperature gradients, DT, with the hot side temperature up to 1153 K. At ΔT ≈756 K, the maximum conversion efficiency reached a value of ∼5%, which is about 65% of that expected from the materials without parasitic losses. The long-term stability investigation for two weeks at the hot and cold side temperatures of 1153/397 K shows that the segmented leg has good durability as a result of stable and low electrical resistance contacts. 2015 Elsevier Ltd. All rights reserved.