Perspectives on manufacturing simulations of Li-S battery cathodes

Lithium-Sulfur Batteries (LSBs) are one of the main contenders for next generation post lithium-ion batteries. As the process of scientific discovery advances, many of the challenges that prevent the commercial deployment of LSBs, specially at the most fundamental materials level, are slowly being addressed. However, batteries are complex systems that require not only from identifying suitable materials, but also from knowing how to assemble and manufacture all the components together in order to obtain an optimally working battery. This is not a simple task, as battery manufacturing is a multi-stepped, multi-parameter, highly correlated process, where many parameters compete, and deep knowledge of the systems is required in order to achieve the optimal manufacturing conditions, which has already been shown in the case of Lithium-Ion Batteries (LIBs). In these regards, manufacturing simulations have proven to be invaluable in order to advance in the knowledge of this exciting and technologically relevant field. Thus, in this work, we aim at providing future perspectives and opportunities that we think are interesting in order to create digital twins for the LSB manufacturing process. We also provide comprehensive and realistic ways in which already existing models could be adapted to LSBs in the short-term, and which are the challenges that might be found in the way.

Key properties of inorganic thermoelectric materials – tables (version 1)

This paper presents tables of key thermoelectric properties, which define thermoelectric conversion efficiency, for a wide range of inorganic materials. The 12 families of materials included in these tables are primarily selected on the basis of well established, internationally-recognised performance and their promise for current and future applications: Tellurides, Skutterudites, Half Heuslers, Zintls, Mg-Sb Antimonides, Clathrates, FeGa3–type materials, Actinides and Lanthanides, Oxides, Sulfides, Selenides, Silicides, Borides and Carbides. As thermoelectric properties vary with temperature, data are presented at room temperature to enable ready comparison, and also at a higher temperature appropriate to peak performance. An individual table of data and commentary are provided for each family of materials plus source references for all the data.

2022 Roadmap on 3D Printing for Energy

This roadmap aims to define the guidelines to maximise the impact of the 3D printing revolution on the next generation of devices for the energy transition. It also outlines the current status, challenges and required advances in Science and Technology for a series of power generation technologies (fuel cells, solar cells, thermoelectric generators and turbomachinery) and energy storage technologies (electrolysers, batteries and supercapacitors). Finally, the roadmap discusses the role of 3D printing in improving the mass and heat transfer to improve the energy efficiency of chemical reactors (CO2 conversion) and novel cooling systems. With this document, the authors intend to provide a valuable tool for researchers, technology developers, and policymakers when defining their strategies for the energy sector's future.

Photo de-mixing in mixed halide perovskites: the roles of ions and electrons

Mixed halide perovskites have attracted great interest for applications in solar cells, light emitting diodes and other optoelectronic devices due to their tunability of optical properties. However, these mixtures tend to undergo de-mixing into separate phases when exposed to light, which compromises their operational reliability in devices (photo de-mixing). Several models have been proposed to elucidate the origin of the photo de-mixing process, including the contribution of strain, electronic carrier stabilization due to composition dependent electronic energies, and light induced ionic defect formation. In this perspective we discuss these hypotheses and focus on the importance of investigating defect chemical and ion transport aspects in these systems. We discuss possible optoionic effects that can contribute to the driving force of de-mixing and should therefore be considered in the overall energy balance of the process. These effects include the selective self-trapping of photo-generated holes as well as scenarios involving multiple defects. This perspective provides new insights into the origin of photo de-mixing from a defect chemistry point of view, raising open questions and opportunities related to the phase behavior of mixed halide perovskites.

Faradaic efficiency in protonic-ceramic electrolysis cells

Proton-conducting ceramics (e.g., doped barium zirconates or cerates) are typically mixed ionic-electronic conductors (MIEC). The electronic conduction, typically in the form of positively charged small polarons or electron holes, leads to “electronic leakage.” In an ideal steam-electrolysis cell, one gas-phase H2 molecule is produced from every two electrons delivered from an external power source. In other words, such ideal behavior achieves 100% faradaic efficiency. However, the electronic flux associated with MIEC membranes contributes to reduced faradaic efficiency. The present paper develops a model that predicts the behavior of faradaic efficiency as a function of electrolysiscell operating conditions. Although the model framework is more general, the paper focuses on the behavior of a cell based upon a BaCe0.7Zr0.1Y0.1Yb0.1O3−δ (BCZYYb) membrane. The study predicts the effects of operating conditions, including temperature, pressure, and gas compositions.

Thermoelectric efficiency of anisotropic materials with an application in layered systems

Thermoelectric transport in anisotropic materials is investigated based on most general thermodynamical concepts. Currents and power conversion efficiency are studied in SnSe and SnS in different directions. The design of composites whose thermoelectric performance along different principles directions is the same is proposed. Although such features do not occur naturally, such man-made anisotropic materials can be constructed using bilayers achieving much broadened working conditions of thermoelectric conversion devices. Intricate relationships between the anisotropy and the direction of the electric and heat currents are revealed, which further help us understand how transport occurs in such composites.