Performance of Low-Cost Thermoelectric Modules Fabricated from Hot Pressing and Cold Pressing Materials

The present work is focus on thermoelectric materials synthesized by economical technique and less production time for low-cost thermoelectric module fabrication. Bi _x Sb _2-x Te ₃ polycrystalline with x = 1.6 for n-type and x = 0.45 for p-type thermoelectric materials were synthesized using two different methods, hot pressing and cold pressing process. The thermoelectric properties were measured at room temperature. The obtained ingots were cut into pellets of 3.5 x 3.5 mm ² in cross-section and 3.8 mm in height. Two kinds of thermoelectric modules consist of seven pairs of n-p pellets from each process were constructed on aluminum substrates with polymer layer and copper layer on the top. The performances of the two modules were evaluated with temperature difference between hot side and cold side up to 100 degC. The internal resistance of hot pressing material modules is 152 mOmega, the open circuit generated voltage is 152 mVK ^-1 . For cold pressing materials module, the internal resistance is 175 mOmega, the opened circuit voltage generated is 1.75 mVK ^-1 .The maximum output power of 70.1 mW and 71.1 mW at 100 degC in temperature difference were obtained from the hot pressing material module and the cold pressing materials module respectively