Caracterización, modelación y comparación de baterías empleadas en electromovilidad en base a su carga y descarga

En el presente artículo de investigación se realiza la caracterización, modelación y comparación de tres baterías eléctricas usadas en electromovilidad: ion-Litio, Plomo Acido e Hidruro metálico de Níquel; con el fin de determinar cuál es la más eficiente, en función de los datos obtenidos en la estimación del estado de carga. Para realizar la estimación del estado de carga se realiza la modelación la batería con el modelo de circuito equivalente de Thévenin y el algoritmo de Conteo de Amperios de Coulomb para la caracterización y modelación de parámetros eléctricos, los cuales nos servirán para estimar el estado de carga de la batería. Al realiza la simulación de los parámetros eléctricos, los datos obtenidos indican que la batería más eficiente es la batería de ion-Litio, ya que es la que presenta un mejor rendimiento en el estado de carga, en comparación a las otras baterías analizadas; mientras que la batería de Plomo acido es la menos eficiente en el escenario de carga y en el escenario de descarga, presentando una descarga profunda.In this article, the characterization, modeling and comparison of three electric batteries used in electromobility are carried out: Lithium-ion, Lead Acid and Nickel Metal Hydride; in order to determine which is the most efficient, based on the data obtained in the estimation of the state of charge. To estimate the state of clyharge, the battery uses the Thevenin equivalent circuit model and the Coulomb Amp Counting algorithm for the characterization and modeling of electrical parameters, which will help estimate the state of charge of the battery. When performing the simulation of the electrical parameters, the data obtained indicate that the most efficient battery is the Lithium-Ion battery, since it has better performance in the state of charge, compared to the other batteries analyzed; while the lead acid battery is the least efficient, in both scenarios, charge and in the discharge, presenting a deep discharge

Development of X-ray Tomography Tools for Characterisation of Lithium-Sulfur Batteries

Electrochemical energy storage devices are becoming increasingly ubiquitous in both consumer and industrial applications, driven by a pressing need to reduce carbon emissions for the mitigation of global warming. The electrification of the transport and mobility sector and growth in portable electronic devices demand portable power sources with high energy densities, and lithium-ion (Li-ion) batteries have been adopted extensively in these applications. However, conventional transition metal oxide-based intercalation materials used at the positive electrode are reaching their theoretical limitations, and only relatively minor improvements in theoretical specific capacity can be achieved. // Lithium-sulfur (Li-S) batteries offer higher gravimetric theoretical specific capacity and energy density and are billed as a potential successor to Li-ion technology but suffer from limited cycle life and self-discharge due to complex multi-phase chemistry and parasitic side reactions. // To better understand the fundamental mechanisms behind these processes, advanced characterisation methods involving the use of penetrating radiation (such as X-rays and neutrons) have become invaluable tools to capture the operation and degradation of the Li-S battery. Three-dimensional techniques such as X-ray micro-tomography (micro-CT) are particularly suited to probe the heterogeneous nature of battery electrode microstructures. // In this thesis, main areas of focus will include the application of ex situ and in situ X-ray micro-CT on Li-S batteries and the broader development of in situ tomography cells. The overall scientific aims of this thesis include: measuring the three-dimensional microstructural characteristics of sulfur electrodes; elucidating the three-dimensional nature of both sulfur dissolution and redeposition as a function of state of charge; and developing a better understanding of the transport processes occurring within the Li-S battery and the influence of porosity and tortuosity on electrochemical performance. In parallel, the development of in situ tomography cells capable of electrochemical cycling is an extensive component of this thesis, with applications not solely limited to Li-S batteries or X-ray micro-CT

NASA/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program, 1985

The 1985 NASA/ASEE Summer Faculty Fellowship Research Program was conducted by Texas A&M University and the Johnson Space Center. The ten week program was operated under the auspices of the American Society for Engineering Education (ASEE). The faculty fellows spent the time at JSC engaged in research projects commensurate with their interests and background and worked in collaboration with NASA/JSC colleagues. This document is a compilation of the final reports of their research during the summer of 1985

Cumulative index to NASA Tech Briefs, 1986-1990, volumes 10-14

Tech Briefs are short announcements of new technology derived from the R&D activities of the National Aeronautics and Space Administration. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This cumulative index of Tech Briefs contains abstracts and four indexes (subject, personal author, originating center, and Tech Brief number) and covers the period 1986 to 1990. The abstract section is organized by the following subject categories: electronic components and circuits, electronic systems, physical sciences, materials, computer programs, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

Development of microtubular solid oxide fuel cells design, fabrication and performance.

Solid oxide fuel cells (SOFCs) are the most efficient energy conversion devices known. Many designs exist, with most current ones based on planar, tubular or so-called hybrid geometries. Tubular designs have many advantages over planar ones, including robustness and simpler sealing. They suffer from somewhat lower area-specific power density and considerably lower volume-specific power density. The miniaturization of tubular cells offers great improvement to both, and more besides. Pushing the boundaries of state-of-the-art manufacture to ever thinner films increases performance further, greatly advancing the long road to large scale commercialisation of SOFCs. This is only possible via the rigorous selection of materials and careful design – both for optimal performance and for mass manufacture. Previous work by the author established the potential of a novel anode fabrication route as well as showing that even un-optimized electron beam physical vapour deposition (EB-PVD) was capable of creating demonstrator cells. In this work these manufacturing processes receive at least two passes of optimization towards both reproducible fabrication and maximising microtubular SOFC performance. The former was achieved by creating statistically significant quantities to assess reproducibility and studying the underlying science, and the latter was investigated in three aspects: gas transport, electrical and electrochemical. The unique oxidation-reduction route creates robust, highly reproducible anodes with excellent through porosity offering as much as 5 orders of magnitude superior gas permeance to published sources. Nickel tubes (Ni200 5.9 mm OD, 125 μm wall thickness, 100 mm long) were oxidised in air at 1,100 for 42 h and reduced in pure hydrogen at four different temperatures. The extremes (400 °C and 1,000 °C) proved sufficiently promising that both were considered in subsequent stages of experiments and analysis for the final anode design. The morphology of the electrolyte (in particular with respect to gas-tightness) is a critical aspect of SOFC miniaturisation, and a challenge to achieve via mass-manufacture-friendly EB-PVD. The yttria-stabilized zirconia (YSZ) electrolyte deposition was optimized as far as proved possible with the available equipment. While results are more than encouraging there are a number of important concerns to be addressed in future to assure successful commercialization of the design. Accurately measuring gas permeance through the anode-electrolyte tube (sometimes called a half-cell) provides quantified justification. Finally a porous platinum cathode film 300 nm thick was successfully magnetron-sputtered onto the YSZ electrolyte at p Aᵣ100 mTorr, demonstrating the fabrication process and creating complete cells for electrical and electrochemical characterisation.PhD in Manufacturin

Energy, Science and Technology 2015. The energy conference for scientists and researchers. Book of Abstracts, EST, Energy Science Technology, International Conference & Exhibition, 20-22 May 2015, Karlsruhe, Germany

We are pleased to present you this Book of Abstracts, which contains the submitted contributions to the "Energy, Science and Technology Conference & Exhibition EST 2015". The EST 2015 took place from May, 20th until May, 22nd 2015 in Karlsruhe, Germany, and brought together many different stakeholders, who do research or work in the broad field of "Energy". Renewable energies have to present a relevant share in a sustainable energy system and energy efficiency has to guarantee that conventional as well as renewable energy sources are transformed and used in a reasonable way. The adaption of existing infrastructure and the establishment of new systems, storages and grids are necessary to face the challenges of a changing energy sector. Those three main topics have been the fundament of the EST 2015, which served as a platform for national and international attendees to discuss and interconnect the various disciplines within energy research and energy business. We thank the authors, who summarised their high-quality and important results and experiences within one-paged abstracts and made the conference and this book possible. The abstracts of this book have been peer-reviewed by an international Scientific Programme Committee and are ordered by type of presentation (oral or poster) and topics. You can navigate by using either the table of contents (page 3) or the conference programme (starting page 4 for oral presentations and page 21 for posters respectively)

Bibliography of Lewis Research Center technical publications announced in 1992

This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific and engineering work performed and managed by the Lewis Research Center in 1992. All the publications were announced in the 1992 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses

Space station systems: A bibliography with indexes (supplement 9)

This bibliography lists 1,313 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1989 and June 30, 1989. Its purpose is to provide helpful information to researchers, designers and managers engaged in Space Station technology development and mission design. Coverage includes documents that define major systems and subsystems related to structures and dynamic control, electronics and power supplies, propulsion, and payload integration. In addition, orbital construction methods, servicing and support requirements, procedures and operations, and missions for the current and future Space Station are included