Abstract
Although many thermoelectric materials, such as Bi2Te3, PbTe and CoSb3, possess excellent thermoelectric properties, they often contain toxic and expensive elements. Moreover, most of them are synthesized by processes such as vacuum melting, mechanical alloying or solid-state reactions, which are highly energy and time intensive. All these factors limit commercial applications of the thermoelectric materials. Therefore, it is imperative to develop efficient, inexpensive and non-toxic materials and explore rapid and low-cost synthesis methods. Herein we demonstrated a rapid, facile and low-cost synthesis route that combines thermal explosion (TE) with plasma-activated sintering and used it to prepare environmentally benign CuFeS2+2x. The phase transformation that occurred during the TE and correlations between the microstructure and transport properties were investigated. In a TE process, single-phase CuFeS2 was obtained in a short time and the thermoelectric performance of the bulk samples was better than that of the samples that were synthesized using traditional methods. Furthermore, the effect of phase boundaries on the transport properties was investigated and the underlying physical mechanisms that led to an improvement in the thermoelectric performance were revealed. This work provides several new ideas regarding the TE process and its utilization in the synthesis of thermoelectric materials.
Highlights
In the past few decades, increased concerns regarding environmental degradation and rising energy costs have sparked vigorous research activities to identify alternative energy sources and develop novel energy materials
To determine whether CuFeS2 can be synthesized by thermal explosion (TE) and how the formation of CuFeS2 proceeded during the TE synthesis, differential scanning calorimetry (DSC) was employed to track the heat flow during the process
We tested whether CuFeS2 can be synthesized by TE by heating the pellet in the DSC apparatus to 823 K
Summary
In the past few decades, increased concerns regarding environmental degradation and rising energy costs have sparked vigorous research activities to identify alternative energy sources and develop novel energy materials. A canonical example is the non-toxic and earth-abundant chalcopyrite compound CuFeS2, which possesses a high Seebeck coefficient (–480 μV K − 1 at room temperature)[34,35] and is considered a promising n-type thermoelectric material. Researchers at the Wuhan University of Technology[46] have developed a combustion synthesis technology that is suitable for the rapid fabrication of many thermoelectric materials, including Bi2Te347, CoSb348, Cu2Se46 and MnSi1.7549, and proposed a new criterion for the applicability of this technology. To investigate the effect of the phase boundary on the transport properties, the Bergman-Fel model[50,51] was used to analyze the thermal conductivity, electrical conductivity and Seebeck coefficient, and in the process we demonstrated the critical role of the phase boundary in improving the thermoelectric properties of the composite structure. We estimated the overall accuracy of the measured ZT values to be approximately ± 10%
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
