| dc.description.abstract | In recent years, the depletion of energy resources and the increasing awareness of environmental issues have driven the development of renewable and recyclable energy materials, making it a prevailing trend. Thermoelectric materials, capable of directly converting electrical energy into thermal energy and vice versa, have emerged as functional materials with significant potential in waste heat recovery. They possess desirable characteristics such as energy efficiency, zero carbon emissions, and low pollution, making them a subject of extensive research. However, relying on a single N-type thermoelectric material is insufficient. The formation of thermoelectric devices and modules requires the series connection of multiple pairs of N-type and P-type thermoelectric materials. Moreover, considering the utilization of thermoelectric modules in high-temperature environments, the bonding technology between thermoelectric block materials and electrodes, as well as the prevention of element diffusion, holds paramount importance.
The focus of this study is the N-type Mg2(SiSn) thermoelectric material. To enhance the production of thermoelectric (TE) blocks, we have refined the manufacturing process to increase the yield of Mn5Si3. Simultaneously, it is crucial to identify contact metals with low resistivity, high mechanical strength, excellent thermal stability, and minimal reactivity with the thermoelectric samples. These metals were bonded to the surface of the thermoelectric materials through cold pressing, followed by annealing to ensure reliable bonding. Additionally, a low-temperature annealing process was conducted after extended annealing to facilitate the attachment of various metals to the samples using solid-state diffusion bonding. Subsequently, electrical measurements and bonding strength tests were carried out. Based on the outcomes obtained from testing different contact metals, the optimal series connection method was determined by combining them with P-type MgAgSb using techniques such as spot welding and low-temperature annealing. Consequently, thermoelectric devices were fabricated, and their performance was evaluated through electrical measurements. Furthermore, thermoelectric modules were assembled for subsequent electrical assessments. | en_US |