High temperature thermoelectric properties and energy transfer devices of Ca3Co4−xAgxO9 and Ca1−ySmyMnO3

The high temperature oxide thermoelectric materials of p-type Ca3Co4−xAgxO9 (denoted as p-Co349/Agx) and n-type Ca1−ySmyMnO3 (denoted as n-Mn113/Smy) were prepared by the self-ignition method combined with a sintering technique. The influence of doping Ag and Sm on the thermoelectric properties of the corresponding materials was evaluated. The figures of merit, ZT, for the p-Co349/Ag0.2 and n-Mn113/Sm0.02 materials reached maxima of 0.20 and 0.15 at 973 K, respectively. The performances of thermoelectric devices constructed with the p- and n-type pairs were evaluated in terms of the maximum output power (Pmax) and manufacturing factor. The Pmax and volume power density for the four-leg devices reached 36.8 mW and 81.9 mW cm−3 at ΔT of 523 K, respectively.

► Doping of Ag and Sm on the thermoelectric properties of high temperature oxide thermoelectric materials of Ca3Co4O9 and CaMnO3 was evaluated.
► The figures of merit ZT for p-Ca3Co3.8Ag0.2O9 and n-Ca0.98Sm0.02MnO3 materials were up to 0.20 and 0.15 at 973 K, respectively.
► The devices constructed with the p- and n-type pairs could generate up to 36.8 mW, which corresponds to volume power density of 81.9 mW cm−3 at ΔT of 523 K.