Ca_(2.7)Bi_(0.3)Co_(4)O_(9)/La_(0.9)Bi_(0.1)NiO_(3) thermoelectric devices with high output power density

摘要

Different versions of a thermoelectric unicouple composed of p-type Ca_(2.7)Bi_(0.3)Co_(4)O_(9) (Co-349) and n-type La_(0.9)Bi_(0.1)NiO_(3) (Ni-113) bulks were constructed using Ag paste containing p- and n-type oxide powders, prepared from the same bulks, for connection of the p and n legs, respectively. Internal resistance (R_(I)) of the unicouple corrected using Ag paste containing 6 wt. % of the oxide powders is 26.2 mΩ at 1073 K in air and decreases with increasing temperature. Maximum output power (P_(max)), evaluated using the formula P_(max)=V_(O)~(2)/4R_(I), (V_(O) is open-circuit voltage), is 94 mW at 1073 K (ΔT=500 K) and increases with temperature. This value corresponds to a volume power density of 0.66 W/cm~(3).