Copper Sulfides: Earth‐Abundant and Low‐Cost Thermoelectric Materials

Abstract

The depletion of nonrenewable energy sources insisted the search for new types of energy solutions. Thermoelectric conversion is one possible energy solution which converts waste heat into useful electricity. In the past several years, thermoelectric research developed many novel materials. Among these, most of the practically useful materials with better performance are based on Bi, Pb, Te, and Sb, but are toxic and expensive. There is a need of earth‐abundant, low‐cost, and less‐toxic compounds with superior thermoelectric performance so as to realize the large‐scale commercial applications. Recent studies have identified eco‐friendly thermoelectric materials based on the alloys of copper and sulfur, suggesting an alternative to the well‐established expensive thermoelectric materials. These compounds exhibit interesting electronic properties with better thermoelectric efficiency (zT). The structural properties permit to decouple electrical and thermal conductivities, which is an essential requirement to get improved efficiency. Several approaches, such as phase tuning, doping, nanostructure/microstructure designing, compound formation, etc., are chosen to increase the performance. On the whole, the present review summarizes the strategies and techniques that have been adopted to improve the thermoelectric behavior of copper sulfides and its compounds.

Promising and Eco‐Friendly Cu2X‐Based Thermoelectric Materials: Progress and Applications

“…Through nonequilibrium processing, Tan et al have achieved a record‐high zT value of 2.5 in Pb 0.98 Na 0.02 Te‐8%SrTe at 923 K. As a potential substitution for highly toxic PbTe, peak zT values of SnTe of ≈1.5 have also been widely reported . More interestingly, multiple studies demonstrate that the peak zT values of superionic Cu 2 X‐based thermoelectric materials can be higher than 2 in the temperature range from ≈800 to ≈1000 K (mainly Cu 2 Se‐based ones) . Strongly anisotropic and stable BiCuSeO with layered structure has also secured the zT values as high as ≈1 at ≈900 K .…”

“…[48,136,138,139] More interestingly, multiple studies demonstrate that the peak zT values of superionic Cu 2 X-based thermoelectric materials can be higher than 2 in the temperature range from ≈800 to ≈1000 K (mainly Cu 2 Se-based ones). [2,120,[122][123][124][125]129,[145][146][147] Strongly anisotropic and stable BiCuSeO with layered structure has also secured the zT values as high as ≈1 at ≈900 K. [94,95] When the temperature is above 1000 K, peak zT values of half Heusler-based thermoelectric materials can reach as high as ≈1.5, [7,9,148,149] especially the NbFeSb-based ones. [7,9,149] From above comparison, Cu 2 X-based thermoelectric materials shows ultrahigh zT values, especially in the temperature range from ≈800 to ≈1000 K, indicating that Cu 2 X-based thermoelectric materials are potential alternatives for the traditional PbTebased thermoelectrics.…”

Thermodynamic study of a synthetic analog of the famatinite mineral - Cu3SbS4

“…From this perspective, copper antimony sulfides (CAS) are being intensively studied as functional materials possessing remarkable properties such as low fabrication temperature, low thermal conductivity, suitable optical band gap, high absorption coefficient, high thermoelectric figure of merit, etc. [1][2][3][4][5][6].…”

From Renewable Energy to Renewable Fuel: A Sustainable Hydrogen Production

“…The low efficiency of the thermoelectric generators is a major drawback to be used independently in the production of hydrogen, and therefore they can be used as a supplementary source by coupling with photovoltaic to improve overall efficiency or production rate (Mulla & Dunnill, 2019). At present, the commercial thermoelectric generators are mainly contained materials like Bi 2 Te 3 and PbTe which makes them quite expensive, and also the elements like tellurium (Te) are highly toxic and scarce hence, a large-scale implementation facing difficulties (Mulla & Dunnill, 2019;Mulla & Rabinal, 2019). Nevertheless, rigorous scientific investigations are under progress which produced many new, low-cost and non-toxic materials and improvements can be realized in the near future (Mulla & Rabinal, 2018;Mulla & Dunnill, 2019).…”