Analysis of two Leveling Courses in Chemistry: objectives, methodology, assessments and future prospects

[EN] The purpose of this report is to analyze different aspects of two levelling courses in Chemistry, offered to entry-levels students in the Degree in Geology (Universidad Complutense de Madrid) and in the degree in Agricultural Engineering (Universidad de Almería). We comparatively analyze the motivations for offering the course, its aims and objectives, the course design and finally the methodology ans assessments of the course in both universities. The assessment of the learning process is done through quizzes at the beginning and at the end of the courses. Voluntary and anonymous surveys show that the students are very satisfied with the courses. In the future, the aim is to improve the learning methodology in order to achieve greater student motivationAuthors thank financial support from Universidad de Almería across the “Convocatoria de Grupos Docentes para la Creación de Materiales Didácticos en la Universidad de Almería” program and Prof. J. Luque (Vicedean for Studies and Quality, Faculty of Geology, UCM) for his careful reading of this manuscript.http://ocs.editorial.upv.es/index.php/HEAD/HEAD18Arroyo-De Dompablo, E.; Ibáñez-González, M. (2018). Analysis of two Leveling Courses in Chemistry: objectives, methodology, assessments and future prospects. Editorial Universitat Politècnica de València. 177-184. https://doi.org/10.4995/HEAD18.2018.792917718

Problemas de Química Inorgánica: elementos metálicos y sus compuestos

6 horasDepto. de Química InorgánicaFac. de Ciencias QuímicasunpubLos problemas aquí presentados se han elaborado para estudiantes de la asignatura de Química Inorgánica I del Grado en Química de la Facultad de Ciencias Químicas de la Universidad Complutense de Madrid. Se abordan aspectos relevantes de los elementos metálicos, como la fortaleza del enlace y su reactividad. Se estudian también algunos de los tipos de compuestos que pueden forman, prestando espacial atención a los sólidos iónicos

Cuestiones para el laboratorio de Química General para geólogos

Este trabajo propone una serie de adaptaciones de las prácticas de Química General de cara a su especialización en el ámbito de la Geología. En concreto, las propuestas se refieren a las prácticas que suelen recogerse bajo los nombres de “Purificación de sólidos por recristalización” y “Equilibrios de oxidación-reducción”. Las modificaciones sugeridas no pretenden sustituir a las prácticas tradicionales, si no completar la formación del alumno en aspectos fundamentales que le permitan establecer una relación entre los conceptos químicos que está adquiriendo y los geológicos que ya conoce

Primer cuaderno de actividades de “Química de Campo” para geólogos: propuestas para la enseñanza de la Química General en Grados en Geología y afines

Este cuaderno, destinado a la enseñanza de la Química General el Geología y grados afines, recoge una serie de Actividades de “Química de Campo” que abordan importantes conceptos del temario de Química General como son el enlace, la termodinámica de sólidos, y el equilibrio químico

Ejercicios de Introducción a la teoría de bandas

Ejercicios elaborados para alumnos de la asignatura Quñimica Inorgánica I del Grado en Químicas de la UCM, como primera aproximación a la teoría de bandas en sólidos, a partir de los modelos del enlace firme y del electrón libre. A través del estudio de hipotéticos casos sencillos y de fácil compresión, el alumno se familiariza con conceptos fundamentales como pueden ser el solapamiento orbital, el vector de ondas o la densidad de estados

Evaluation of cobalt oxides for calcium battery cathode applications

The identification of potential cathode materials is a requirement for the development of a rechargeable calcium based battery technology. In this work, we use Density Functional Theory (DFT) calculations to explore the electrode characteristics of three ternary calcium cobalt oxides with distinct CoeO dimensionality: 3D-Ca2Co2O5 (brownmillerite type structure), 2D-Ca3Co4O9 (a misfit compound) and 1D-Ca3Co2O6 (K4CdCl6 structural type). For the three compounds calculations predict Co3+/Co4+ voltages in the 3–4 V range, with a volume variation below 8% upon Ca deinsertion. Further Co4+ oxidation is predicted at too high voltages not reachable in practice. The maximum specific capacities are therefore 192 mAh/g (Ca2Co2O5), 165 mAh/g (Ca3Co4O9) and 160 mAh/g (Ca3Co2O6). The potential application of Ca2Co2O5 is discarded based on a large energy barrier for Ca diffusion (1.3 eV). With energy barriers for Ca diffusion of 0.9 eV, the 2D and 1D oxides are appealing as low rate cathode materials. To complete a previous experimental investigation, we have analyzed the reversibility of the Ca deinterclation reaction of 1D-Ca3Co2O6. It is found that a phase transformation takes place upon decalciation driven by the change in the electronic configuration of Co ions (from High Spin-trigonal prismatic Co3+ to octahedral Low Spin-Co4+) and involving the Ca diffusion pathways

Achievements, Challenges, and Prospects of Calcium Batteries

This Review flows from past attempts to develop a (rechargeable) battery technology based on Ca via crucial breakthroughs to arrive at a comprehensive discussion of the current challenges at hand. The realization of a rechargeable Ca battery technology primarily requires identification and development of suitable electrodes and electrolytes, which is why we here cover the progress starting from the fundamental electrode/electrolyte requirements, concepts, materials, and compositions employed and finally a critical analysis of the state-of-the-art, allowing us to conclude with the particular roadblocks still existing. As for crucial breakthroughs, reversible plating and stripping of calcium at the metal-anode interface was achieved only recently and for very specific electrolyte formulations. Therefore, while much of the current research aims at finding suitable cathodes to achieve proof-of-concept for a full Ca battery, the spectrum of electrolytes researched is also expanded. Compatibility of cell components is essential, and to ensure this, proper characterization is needed, which requires design of a multitude of reliable experimental setups and sometimes methodology development beyond that of other next generation battery technologies. Finally, we conclude with recommendations for future strategies to make best use of the current advances in materials science combined with computational design, electrochemistry, and battery engineering, all to propel the Ca battery technology to reality and ultimately reach its full potential for energy storage

In quest of cathode materials for Ca ion batteries: the CaMO3 perovskites (M = Mo, Cr, Mn, Fe, Co, and Ni)

Basic electrochemical characteristics of CaMO3 perovskites (M = Mo, Cr, Mn, Fe, Co, and Ni) as cathode materials for Ca ion batteries are investigated using first principles calculations at the Density Functional Theory level (DFT). Calculations have been performed within the Generalized Gradient Approximation (GGA) and GGA+U methodologies, and considering cubic and orthorhombic perovskite structures for CaxMO3 (x = 0, 0.25, 0.5, 0.75 and 1). The analysis of the calculated voltage–composition profile and volume variations identifies CaMoO3 as the most promising perovskite compound. It combines good electronic conductivity, moderate crystal structure modifications, and activity in the 2–3 V region with several intermediate CaxMoO3 phases. However, we found too large barriers for Ca diffusion (around 2 eV) which are inherent to the perovskite structure. The CaMoO3 perovskite was synthesized, characterized and electrochemically tested, and results confirmed the predicted trends.The authors would like to thank F. Rosciano for advice and support in synthesizing the perovskite material and A. Ponrouch and D. Tchitchekova for assistance with the electrochemical tests. The Toyota Battery Research division at Higashi Fuji (M6) is acknowledged for financial support and ICMAB authors are grateful to the Spanish Ministry of Economy and Competitiveness for support through the ‘‘Severo Ochoa’’ Programme for Centres of Excellence in R&D (SEV-2015-0496). M. E. Arroyo acknowledges access to computational resources from Universidad de Oviedo (MALTA-Consolider cluster) and to A. Saracibar for assistance in the analysis of DFT data and fruitful discussions.Peer reviewe

Polymorphs by Pressure

Depto. de Química InorgánicaFac. de Ciencias QuímicasTRUEpu