Novel multilayer composite structured thermoelectric module with high output power

Output power is a vital criterion for evaluating the heat–electricity conversion capability of thermoelectric power generators (TEGs). This study for the first time proposes a novel (Bi,Sb)2Te3-based multilayer composite structured thermoelectric module (MCTEM) that can achieve high power output. Parallel heat transfer and electrical parallel connection are simultaneously achieved in an n-type single-leg MCTEM which is composed of several alternately stacked thermoelectric slices and inner electrodes. The extremely low inner resistance (Rin) and high current (I) are 0.03 and 12.7 times those measured in a single-leg traditional module, respectively, and then a maximum output power (Pmax) of 5.8 mW is achieved at ΔT = 35 °C. The effect of the slice number on module performance has been investigated, and the optimal Pmax for n- and p-type single-leg MCTEMs has been achieved when using 3 slices. Based on the optimized single-leg MCTEMs mentioned above, a π-type MCTEM has been designed to improve the output voltage (V) and further enhance the Pmax. The π-type MCTEM achieves a high V of 3.1 mV while maintaining a low Rin of 0.94 mΩ and a large I value of 3.3 A, and then a Pmax of 10.5 W is obtained which is 4.2 times that of the traditional module at ΔT = 35 °C. This new design of a MCTEM provides enlightenment for fabrication and commercialization through the development of high-power TEGs.