Fabrication and thermoelectric power of π-shaped Ca3Co4O9/CaMnO3 modules for renewable energy conversion

The thermoelectric modules of π-shaped 1-, 2-, and 4-pairs are constructed using p-type Ca2.76Cu0.24Co4O9 and n-type Ca0.8Dy0.2MnO3 oxide materials. The reacted phases at the interfaces of the Ca2.76Cu0.24Co4O9/Ag electrode and Ca0.8Dy0.2MnO3/Ag electrode are not observed. The output powers of the fabricated π-shaped modules are measured, depending on the operating parameters and number of thermoelectric module pairs. The output powers of single thermoelectric modules increase with an increase in temperature difference ΔT between the hot- and cold-side temperatures of the modules, i.e., 2.42, 3.65, 4.26, 5.70, 7.13, and 8.42 mW for ΔT = 250, 269, 293, 305, 324, and 346 °C, respectively. The maximum output powers of 1-, 2-, and 4-pair thermoelectric modules are roughly proportional to the number of p-n pairs. Oxide-based thermoelectric devices can be considered useful tools for green energy generation.