Oxidation Protective Hybrid Coating for Thermoelectric Materials

Gucci, Francesco; D’Isanto, Fabiana; Zhang, Ruizhi; Reece, Michael J.; Smeacetto, Federico; Salvo, Milena

doi:10.3390/ma12040573

Cited by 14 publications

(10 citation statements)

References 48 publications

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“…The investigation of suitable coating and annealing conditions should therefore be prioritized for further TEG development, see, e.g., Refs. [58][59][60][61][62][63].…”

Section: Discussionmentioning

confidence: 99%

Overcoming Asymmetric Contact Resistances in Al-Contacted Mg2(Si,Sn) Thermoelectric Legs

et al. 2021

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Thermoelectric generators are a reliable and environmentally friendly source of electrical energy. A crucial step for their development is the maximization of their efficiency. The efficiency of a TEG is inversely related to its electrical contact resistance, which it is therefore essential to minimize. In this paper, we investigate the contacting of an Al electrode on Mg2(Si,Sn) thermoelectric material and find that samples can show highly asymmetric electrical contact resistivities on both sides of a leg (e.g., 10 µΩ·cm2 and 200 µΩ·cm2). Differential contacting experiments allow one to identify the oxide layer on the Al foil as well as the dicing of the pellets into legs are identified as the main origins of this behavior. In order to avoid any oxidation of the foil, a thin layer of Zn is sputtered after etching the Al surface; this method proves itself effective in keeping the contact resistivities of both interfaces equally low (<10 µΩ·cm2) after dicing. A slight gradient is observed in the n-type leg’s Seebeck coefficient after the contacting with the Zn-coated electrode and the role of Zn in this change is confirmed by comparing the experimental results to hybrid-density functional calculations of Zn point defects.

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“…The investigation of suitable coating and annealing conditions should therefore be prioritized for further TEG development, see, e.g., Refs. [58][59][60][61][62][63].…”

Section: Discussionmentioning

confidence: 99%

Overcoming Asymmetric Contact Resistances in Al-Contacted Mg2(Si,Sn) Thermoelectric Legs

et al. 2021

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“…(a) T -dependent S 2 σ of Cu 11.5 Zn 0.5 Sb 4 S 13 pellets before and after aging in air and protected by resin after aging in air; inset cross-sectional SEM images show the surface of pellets after aging in the air without and with resin protection. Reprinted from ref under the terms of a Creative Common CC BY License. Copyright 2019 MDPI.…”

Section: Device Designmentioning

confidence: 99%

“…Figure 41a shows T-dependent S 2 σ of Cu 11.5 Zn 0.5 Sb 4 S 13 pellets before and after aging in air and pellets protected by resin after aging in air. 905 The inset cross-sectional SEM images show the surface of pellets after aging in the air without and with resin protection. 905 The pellets were fabricated by a combination of ball-milling and hot-pressing.…”

Section: Chemicalmentioning

confidence: 99%

“…905 The inset cross-sectional SEM images show the surface of pellets after aging in the air without and with resin protection. 905 The pellets were fabricated by a combination of ball-milling and hot-pressing. The fresh pellet has a high S 2 σ of ∼11.6 μW cm −1 K −2 at ∼623 K. After aging at 623 K in the air for 48 h, there was a thick inhomogeneous layer of oxide (mainly Sb 2 O 3 around 3−5 μm confirmed by XRD) on the surface of the pellet, resulting in a drop of S 2 σ in the entire temperature range, especially at ∼623 K with a low value of ∼6.5 μW cm −1 K −2 .…”

Section: Chemicalmentioning

confidence: 99%

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Advanced Thermoelectric Design: From Materials and Structures to Devices

2020

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The long-standing popularity of thermoelectric materials has contributed to the creation of various thermoelectric devices and stimulated the development of strategies to improve their thermoelectric performance. In this review, we aim to comprehensively summarize the state-of-the-art strategies for the realization of high-performance thermoelectric materials and devices by establishing the links between synthesis, structural characteristics, properties, underlying chemistry and physics, including structural design (point defects, dislocations, interfaces, inclusions, and pores), multidimensional design (quantum dots/wires, nanoparticles, nanowires, nano-or microbelts, few-layered nanosheets, nano-or microplates, thin films, single crystals, and polycrystalline bulks), and advanced device design (thermoelectric modules, miniature generators and coolers, and flexible thermoelectric generators). The outline of each strategy starts with a concise presentation of their fundamentals and carefully selected examples. In the end, we point out the controversies, challenges, and outlooks toward the future development of thermoelectric materials and devices. Overall, this review will serve to help materials scientists, chemists, and physicists, particularly students and young researchers, in selecting suitable strategies for the improvement of thermoelectrics and potentially other relevant energy conversion technologies.

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“…Many materials for a variety of energy applications are susceptible to rapid oxidation under potential operating conditions. − While excellent properties of a material might be exhibited under an inert atmosphere or vacuum, in the presence of even small amounts of water, oxygen, and heat, these beneficial properties may degrade. In the example of thermoelectric materials, new materials have been prepared, showing high thermoelectric efficiencies, but in many cases, little is known about their oxidation kinetics and chemical reactions at device working temperatures. − …”

Section: Introductionmentioning

confidence: 99%

Probing High-Temperature Oxidation of Thermoelectric Phases Yb₁₄MSb₁₁ (M = Mg, Mn, Zn)

Justl

Kauzlarich

2022

ACS Appl. Mater. Interfaces

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Yb14 MSb11 (M = Mg, Mn, Zn) are p-type Zintl phases with high thermoelectric efficiencies at 1000 °C and melting points above 1200 °C under vacuum and/or inert atmosphere. In a thermoelectric generator, even within a vacuum jacket, small amounts of oxygen may be present, and therefore, elucidating chemical reactions in the presence of air or oxygen provides a framework for engineering design. The oxidation of Yb14 MSb11 was investigated from room temperature to 1000 °C in dry air with thermogravimetric/differential scanning calorimetry (TG/DSC) on small pellets and visually after heat treatment to 1000 °C under ambient conditions on large pellets. Scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS) and powder X-ray diffraction provide identification of the oxidation products. In the presence of dry air, Yb14 MSb11 initially oxidizes initially slowly at room temperature with a sweeping exotherm and weight gain with rapid oxidation at 400 °C, after which the exotherm signal plateaus at about 600 °C, with M = Zn showing the smallest overall exothermic curve. All samples showed a paired endo-/exotherm at 785–803 °C, consistent with the melting/solidification of YbSb2, which in the case of M = Mg, Mn extrudes from the sample. The various sections of the pelletsouter layer, inner layer, and core are analyzed, and oxidation reactions are proposed. After cycling to 1000 °C, the outer layer is composed of Yb2O3 with small amounts of the corresponding metal oxides. The inner layer shows delamination by inward diffusion of oxygen and outward diffusion of Sb or Sb oxide-containing phases, and the core shows Yb14 MSb11. Yb14ZnSb11 shows the best resistance to oxidation and may provide a promising material for further passivation optimization.

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Oxidation Protective Hybrid Coating for Thermoelectric Materials

Cited by 14 publications

References 48 publications

Overcoming Asymmetric Contact Resistances in Al-Contacted Mg2(Si,Sn) Thermoelectric Legs

Overcoming Asymmetric Contact Resistances in Al-Contacted Mg2(Si,Sn) Thermoelectric Legs

Advanced Thermoelectric Design: From Materials and Structures to Devices

Probing High-Temperature Oxidation of Thermoelectric Phases Yb₁₄MSb₁₁ (M = Mg, Mn, Zn)

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Oxidation Protective Hybrid Coating for Thermoelectric Materials

Cited by 14 publications

References 48 publications

Overcoming Asymmetric Contact Resistances in Al-Contacted Mg2(Si,Sn) Thermoelectric Legs

Overcoming Asymmetric Contact Resistances in Al-Contacted Mg2(Si,Sn) Thermoelectric Legs

Advanced Thermoelectric Design: From Materials and Structures to Devices

Probing High-Temperature Oxidation of Thermoelectric Phases Yb14MSb11 (M = Mg, Mn, Zn)

Contact Info

Product

Resources

About

Probing High-Temperature Oxidation of Thermoelectric Phases Yb₁₄MSb₁₁ (M = Mg, Mn, Zn)