Thermoelectric MgAgSb alloys for sustainable energy application

Abstract

Summary Solid‐state thermoelectric (TE) devices are known for converting solar energy and waste heat into electricity, which provides a substitute path for energy production and utilization to commence the challenges of energy sustainability. To develop TE devices, it is important to identify thermoelectrically active materials with the potential converting solar energy and heat into electrical energy. In ambient settings, TE devices are one of the most pollution‐free methods of energy conversion since it is noiseless, essentially maintenance‐free, and able to provide electricity continuously for several years. A surge in interest in TE harvesting for diverse uses, including extracting waste heat from automobile exhaust and industrial processes has occurred in recent years. For an efficient TE device, a number of variables must be addressed. These include the availability of TE materials with high ZT, construction of ohmic connections between thermoelements and metallic interconnect, material engineering and defects systems, and the control of maximum heat transport through the device. The current review summarized a recent understanding of a reliable and eco‐friendly strategy for synthesizing pure MgAgSb alloy and its TE performance enhancement. First, a discussion on the various strategies employed to improve ZT and band structure determination is described. Then, we provided an overview of excellent TE performance, applications of bandgap engineering to enhance TE ZT value and their capacity to produce energy, and good quality nanostructured a‐MgAgSb to produce long‐term, thermally stable microstructure. Finally, we will look at how well a single‐leg device converts power. The current mysteries, along with future perspectives and challenges for this material system, are described in the outlook section.

Defect Engineering in Nanocatalysts: From Design and Synthesis to Applications

“…Defect engineering shows potential as defects' appearance, types, concentration, and distribution significantly influence the regulation of the chemical, electronic, and surface properties of the nanostructure of catalysts. [ 24 ] Due to their finely calibrated electrical and surface characteristics, defects often seen in nanomaterials are known as the active sites for catalytic reactions. Theoretical studies corroborate experimental findings that specific defects induce active sites for distinct electrochemical reactions (ORR, OER, and HER) due to the highly desirable reactant binding energy associated with each response.…”

Structure and Thermoelectric Properties of Mg1–xTixNiSb Quaternary Half-Heusler Alloys

“…Half-Heusler (HH) alloys hold broad application prospects in various fields, including thermoelectrics, spintronics, topological insulators, and semiconductor thin films . In recent years, HH alloys have garnered growing interest, particularly as viable candidates for medium- to high-temperature thermoelectric applications, owing to their exceptional attributes including remarkable thermal stability, mechanical properties, and electrical properties . Traditional ternary HH compounds with the chemical formula XYZ typically crystallize in the face-centered-cubic (fcc) MgAgAs-type structure with the space group F 4̅3 m .…”

“…4 In recent years, HH alloys have garnered growing interest, particularly as viable candidates for medium-to high-temperature thermoelectric applications, owing to their exceptional attributes including remarkable thermal stability, mechanical properties, and electrical properties. 5 Traditional ternary HH compounds with the chemical formula XYZ typically crystallize in the facecentered-cubic (fcc) MgAgAs-type structure with the space group F4̅ 3m. This typical structure features three distinct atomic positions: 4a (0, 0, 0), 4b (0.5, 0.5, 0.5), and 4c (0.25, 0.25, and 0.25), each occupied by X, Z, and Y atoms, respectively.…”

“…Consequently, it is imperative to explore effective strategies to reduce the lattice thermal conductivity of HH thermoelectric materials. 5,8 Recently, Anand et al noted that quaternary HH alloys (referred as "double HH" in their work) offer a significantly large composition space for materials exploration. 9 These quaternary HH alloys are solid solutions formed by combining 17-with 19-electron HH compounds, all while retaining the cubic MgAgAs-type structure of the parent compound.…”

“…However, HH alloys face the challenge of relatively high thermal conductivity, which can exceed 10 W m –1 K –1 at room temperature. Consequently, it is imperative to explore effective strategies to reduce the lattice thermal conductivity of HH thermoelectric materials. , …”