Silver Nanoparticles Could Be the Ideal Connective for Thermoelectric Materials

Silver could play an important role when working with thermoelectric materials. A new study found that it could be the ideal connective material.

Silver Nanoparticles for Thermoelectric Materials

Researchers from the University of Houston produced an effective connector of the metallization layers of the modules. They used silver nanoparticles to do the job. The project is anticipated to hasten the creation of cutting-edge modules for power generation and other applications, Mining.com reported

According to the study, the use of silver nanoparticles was examined for stability in modules made of three different cutting-edge thermoelectric materials intended to function at various temperatures.

Because of their potential as a clean energy source, thermoelectric materials have attracted more attention. These materials use the flow of heat current from a warmer area to a cooler area to convert heat, such as waste heat produced by power plants or other industrial processes, into electricity.

Finding a material that can connect the hot and cold sides of the material both electrically and thermally without affecting the material's performance is necessary to take advantage of this capability.

For the solder to remain stable while the device is operating, the connective substance, or solder, must have a higher melting point than the operating temperature since it is often heated to create an interface between the two sides. The connecting layer will remelt if the thermoelectric material runs at hotter temperatures.

High temperatures can impair the stability and performance of the thermoelectric materials during the connecting procedure. Therefore difficulties can also arise if the connective material has a very high melting point, according to Zhifeng Ren, author of the paper and director of the Texas Center for Superconductivity at the University of Houston.

The ideal connecting material would have a relatively low melting point to prevent the thermoelectric materials from becoming unstable during module assembly. However, it could also resist high working temperatures without melting again.

Silver could be the answer due to its high thermal and electrical conductivity. However, it has a comparatively high melting point - 962 degrees Celsius - which may affect the stability of many thermoelectric materials.

Silver Nanoparticles Put to the Test

Silver nanoparticles have far lower melting points than bulk silver, so researchers opted to use them. After the module was put together, the nanoparticles returned to a bulk condition and regained their higher melting point.

Depending on the size of the particles, the melting point of silver made into nanoparticles could be as low as 400 or 500 degrees C. According to Ren, as long as the working temperature stays below the melting point of bulk silver, or 962 C, you can operate the gadget without experiencing any issues at 600 C or 700 C.

They tested the silver nanoparticles' performance with three well-known thermoelectric materials at different temperatures.

A lead tellurium-based module produced a heat-to-electricity conversion efficiency of around 11% and remained stable after 50 thermal cycles. This module operates at low temperatures of about 300 C to 550 C.

Furthermore, they used the silver nanoparticles as the connecting material in modules made of low-temperature bismuth telluride and a half-Heusler high-temperature material, demonstrating that the idea may be used in a variety of thermoelectric materials and applications.

According to Ren, various materials are chosen depending on the intended heat source to make sure the materials can endure the heat.

However, this study demonstrates that, regardless of the material, we may use the same silver nanoparticles for solder if the heat doesn't exceed 960 degrees C, staying below the melting point.

A lead tellurium-based module produced a heat-to-electricity conversion efficiency of around 11% and remained stable after 50 thermal cycles. This module operates at low temperatures of about 300 C to 550 C.

Furthermore, they used the silver nanoparticles as the connecting material in modules made of low-temperature bismuth telluride and a half-Heusler high-temperature material, demonstrating that the idea may be used in a variety of thermoelectric materials and applications.

According to Ren, various materials are chosen depending on the intended heat source to make sure the materials can endure the heat.

Regardless, the study demonstrates that silver nanoparticles could be used for the solder as long as the heat applied doesn't exceed 960 degrees C and stays below the melting point of bulk silver.

The study was published in the journal Nature Energy.

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