Thermodynamic Considerations for Improved Renewable Energy Production

Developing technologies essential to the transition towards a decarbonized energy future require discovery of new energy materials with unique properties and wider thermal and chemical stability ranges. To facilitate this discovery, comprehensive databases of inorganic materials critical to advanced clean energy technologies need to be developed. Recent efforts in advanced energy materials research have made progress in identifying and optimizing promising materials for high-performance energy applications. For instance, Bi-Te-based alloys with high ZT (figure-of-merit) values at room temperature are competitive options for thermoelectric applications in refrigeration and green power conversion from low-temperature waste heat.1

The search for these high-performance energy storage and conversion materials involves the determination of thermal stabilities, phase transformations, phase equilibria with coexisting phases, and other application-relevant thermodynamic properties. The availability of such data also enables efficient and cost-effective materials processing. Figure 1 illustrates the relationship of experimental techniques, computational tools, and materials design that facilitates materials discoveries with unique properties.

Fig. 1

Schematic of components of a comprehensive framework for materials discovery.

The JOM advisors of the Recycling and Environmental Technologies and Process Technology and Modeling technical committees of The Minerals, Metals & Materials Society have organized special topics focused on improved extractions and recoveries of the strategic metals including those important components of energy materials. The most recent publications are summarized in “Thermodynamic Modeling of Sustainable Non-Ferrous Metals Production: Part II”.2 This special topic complements the series by inviting original research papers focusing on the research of energy materials and energy efficiency processes. After peer-review by several experts in the field, six original research articles were selected for publication.

In the work entitled “Synthesis and Thermodynamic Investigation of Energy Materials in the Ag–Te–Cl System by the Solid-State Galvanic Cells”, Moroz et al. have reviewed and experimentally investigated phase stabilities and thermodynamic properties of potential energy materials in the Ag–Te–Cl system. They presented new thermodynamic data of the candidate energy materials, Ag₁₉Te₆Cl₇, Ag₁₀Te₄Cl₃, Ag₅Te₂Cl, and Ag₂₃Te₁₂Cl, below 500 K. Hasanova et al. optimized the phase diagram of the Bi-Te system in their work “Refinement of the Phase Diagram of The Bi-Te System and the Thermodynamic Properties of Lower Bismuth Tellurides”. Their optimization of the phase diagram incorporating Bi₂Te₃, Bi₄Te₅, Bi₈Te₉, BiTe, Bi₄Te₃, Bi₂Te, and Bi₇Te₃ compounds was based on high-temperature synthesis, differential thermal analysis (DTA), X-ray diffraction (XRD), and scanning electron microscopic analyses, as well as electromotive force (EMF) measurements of the samples. The paper “Solid-Phase Equilibria in the Cu-Sb-S System and Thermodynamic Properties of Copper-Antimony Sulfides” by Mashadiyeva et al. investigated the solid-phase equilibria and thermodynamics in the system Cu-Sb-S by means of powder X-ray diffraction (PXRD), DTA, and EMF techniques. Their proposed phase diagram suggests that the chalcogenide functional compounds, Cu₃SbS₄, CuSbS₂, Cu₃SbS₃, Cu₁₂Sb₄S₁₃, and Cu₁₄Sb₄S₁₃, are thermodynamically stable at 300 K. The fourth paper “Solid-Phase Relations in the Tl₂Te-Tl₂Te₃-TlTbTe₂ System and Thermodynamic Properties of Thallium-Terbium Tellurides” by Imamaliyeva et al. presents phase equilibria and thermodynamic data of phases in the Tl–Tb–Te ternary system. According to them, one of the objectives of studying such systems was to explore improved performance and additional functionality of materials because of the introduction of rare-earth elements. They applied the EMF and PXRD analysis techniques to investigate the thermodynamic properties of the equilibrium phases and their relationships in the system.

The last two papers in this topic, “Production of High Purity TiO₂ Powder from FeTiO₃ via High Temperature Sulfurization” by Shin et al. and “A Study on the Roasting Process for Efficient Selective Chlorination of Ilmenite Ores” by Kim et al., present interesting thermodynamic considerations for efficient titanium production through high-temperature processes. Titanium is used in various applications ranging from aerospace parts, power plants, and automotive parts to the medical and steel industries owing to its lightweight and excellent corrosion resistance. In particular, its light weight combined with the other important properties make titanium the choice as an alloying element for energy-efficient applications.

The peer-reviewed articles in this special topic could be of interest to a broad readership, including those promoting efficient recovery of low-temperature waste heat. All the titles and authors of the articles published in the May issue of JOM (volume 73, issue 5) under the special topic “Thermodynamic Considerations for Improved Renewable Energy Production” are listed below. The articles can be fully accessed on the journal’s web page at: http://link.springer.com/journal/11837/73/5/page/1.

• “Synthesis and Thermodynamic Investigation of Energy Materials in the Ag–Te–Cl System by the Solid-State Galvanic Cells” by M. Moroz, F. Tesfaye, P. Demchenko, M. Prokhorenko, S. Prokhorenko, D. Lindberg, O. Reshetnyak, and L. Hupa.

• “Refinement of the Phase Diagram of the Bi-Te System and the Thermodynamic Properties of Lower Bismuth Tellurides” by G. Hasanova, A. Aghazade, S. Imamaliyeva, Y. Yusibov, and M. Babanly.

• “Solid-Phase Equilibria in the Cu-Sb-S System and Thermodynamic Properties of Copper-Antimony Sulfides” by L.F. Mashadiyeva, P.R. Mammadli, D.M. Babanly, G.M. Ashirov, A.V. Shevelkov, and Y.A. Yusibov.

• “Solid-Phase Relations in the Tl₂Te-Tl₂Te₃-TlTbTe₂ System and Thermodynamic Properties of Thallium-Terbium Tellurides” by S. Imamaliyeva, D. Babanly, V. Qasymov, and M. Babanly.

• “Production of High Purity TiO₂ Powder from FeTiO₃ via High Temperature Sulfurization” by S.-H. Shin and S.-J. Kim.

• “A Study on the Roasting Process for Efficient Selective Chlorination of Ilmenite Ores” by J. Kim, Y.R. Lee, and E.J. Jung.