Revisiting the temperature dependence in material properties and performance of thermoelectric materials

Thermoelectric materials play a significant role in energy production and utilization for the near future. However, the temperature-dependent material properties including thermal conductivity, electric resistivity and Seebeck coefficient make the theoretical analysis challenging. In this work, we propose an approximate analytical solution, in which we evaluate the distribution of the electric resistivity and Thomson coefficient linearly, but the distribution of electric resistivity and Thomson coefficient are still nonlinear. The temperature profile obtained from our approximate analytical model agrees well with numerical prediction. More importantly, the derivative of temperature, which has great influence on the heat flux distribution and efficiency, also agrees well with the numerical results. Then the model is applied to analyze the performance of a thermoelectric element. We show that thermal conductivity is critical factor in the performance of thermoelectric materials including the efficiency.