Effects of SiC doping on the thermoelectric properties of Bi1.9Ba0.1Sr2Co2Oy ceramics

As a new type of clean and environmentally friendly energy material that can mutually transform thermal energy and electric energy, thermoelectric materials have received extensive attention from researchers. In this study, the traditional high-temperature solid-phase reaction method was used to prepare Bi 1.9 Ba 0.1 Sr 2 Co 2 O y  +  g wt% SiC ( g  = 0, 0.025, 0.05, 0.1 and 0.15) polycrystalline samples. Ba element was used to substitute the Bi site of Bi 1.9 Ba 0.1 Sr 2 Co 2 O y , in an attempt to change the carrier concentration and raise its electrical transport performance. Then, based on Ba substituting, nano-SiC was introduced as the second phase to increase the grain boundary number, which would enhance phonon scattering and reduce its heat transport performance. Finally, the ZT value of Bi 1.9 Ba 0.1 Sr 2 Co 2 O y + 0.025 wt% SiC reaches 0.35 at 923 K, which is approximately 35 % higher than that of the pure sample Bi 2 Sr 2 Co 2 O y .