Thermoelectric power generation is an emerging renewable energy technology, while its widespread application has been limited by its constrained output capacity. The figure of merit ( \({\text{ZT}}\) ) of thermoelectric materials serves as a crucial metric for performance assessment. However, researchers primarily focus on increasing the numerical value of \({\text{ZT}}\) , neglecting the fact that a high \({\text{ZT}}\) does not directly translate into superior performance. In this study, we employed finite element simulations to analyze the temperature-dependent properties of thermoelectric materials and examined the impact of the Seebeck coefficient, electrical and thermal conductivity on output performance of thermoelectric generators (TEG) during operation. The results reveal that a high \({\text{ZT}}\) does not guarantee superior output performance. Conversely, thermal property of materials exerts more influence on output capacity than electrical property. Through appropriate adjustments, the maximum output power can be increased by up to 13%, or the maximum efficiency can be enhanced by 6% even maintaining the same \({\text{ZT}}\) . Furthermore, we discuss the practical scenarios during operation and demonstrate that excessive external loads or low thermal conductivity can induce significant thermal stress on the thermoelectric device. This study would provide valuable reference for future optimal utilization of TEG to achieve high output performance and stable operation.
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