Fabrication and performance of an oxide thermoelectric power generator

A box-type thermoelectric power generation module was fabricated using polycrystalline oxide materials, /spl gamma/-Na/sub 0.70/CoO/sub 2/ (p-type) and Ca/sub 0.92/La/sub 0.08/MnO/sub 3/ (n-type). The present module (25 mm/spl times/25 mm/spl times/15 mm) implements two p-n couples connected in series and supplied the maximum electric power of 7.6 mW to an external load resistor under the condition of hot side temperature, T/sub h/=345/spl deg/C, and temperature difference, 281/spl deg/C. The module was sufficiently tough for repeated heat cycles up to T/sub h/=345/spl deg/C in air. After a continuous operation at T/sub h/=345/spl deg/C for 10 days, the maximum electric power decreased to 5.6 mW due to the increase in electric resistivity of /spl gamma/-Na/sub 0.70/CoO/sub 2/.