Solid-state Li-ion batteries operating at room temperature using new borohydride argyrodite electrolytes

Using a new class of (BH4)- substituted argyrodite Li6PS5Z0.83(BH4)0.17, (Z = Cl, I) solid electrolyte, Li-metal solid-state batteries operating at room temperature have been developed. The cells were made by combining the modified argyrodite with an In-Li anode and two types of cathode: an oxide, LixMO2 (M = 1/3Ni, 1/3Mn, 1/3Co; so called NMC) and a titanium disulfide, TiS2. The performance of the cells was evaluated through galvanostatic cycling and Alternating Current AC electrochemical impedance measurements. Reversible capacities were observed for both cathodes for at least tens of cycles. However, the high-voltage oxide cathode cell shows lower reversible capacity and larger fading upon cycling than the sulfide one. The AC impedance measurements revealed an increasing interfacial resistance at the cathode side for the oxide cathode inducing the capacity fading. This resistance was attributed to the intrinsic poor conductivity of NMC and interfacial reactions between the oxide material and the argyrodite electrolyte. On the contrary, the low interfacial resistance of the TiS2 cell during cycling evidences a better chemical compatibility between this active material and substituted argyrodites, allowing full cycling of the cathode material, 240 mAhg-1, for at least 35 cycles with a coulombic efficiency above 97%

Algorithms hardware implementation for ultrasonic data processing in SHM system

Nowadays, devices that monitor the health of structures consume a lot of power and need a lot of time to acquire, process, and send the information about the structure to the main processing unit. To decrease this time, fast electronic devices are starting to be used to accelerate this processing. In this paper some hardware algorithms implemented in an electronic logic programming device are described. The goal of this implementation is accelerate the process and diminish the information that has to be send. By reaching this goal, the time the processor needs for treating all the information is reduced and so the power consumption is reduced too

Integration of embedded data processing algorithms inside PAMELA devices

PAMELA (Phased Array Monitoring for Enhanced Life Assessment) SHMTM System is an integrated embedded ultrasonic guided waves based system consisting of several electronic devices and one system manager controller. The data collected by all PAMELA devices in the system must be transmitted to the controller, who will be responsible for carrying out the advanced signal processing to obtain SHM maps. PAMELA devices consist of hardware based on a Virtex 5 FPGA with a PowerPC 440 running an embedded Linux distribution. Therefore, PAMELA devices, in addition to the capability of performing tests and transmitting the collected data to the controller, have the capability of perform local data processing or pre-processing (reduction, normalization, pattern recognition, feature extraction, etc.). Local data processing decreases the data traffic over the network and allows CPU load of the external computer to be reduced. Even it is possible that PAMELA devices are running autonomously performing scheduled tests, and only communicates with the controller in case of detection of structural damages or when programmed. Each PAMELA device integrates a software management application (SMA) that allows to the developer downloading his own algorithm code and adding the new data processing algorithm to the device. The development of the SMA is done in a virtual machine with an Ubuntu Linux distribution including all necessary software tools to perform the entire cycle of development. Eclipse IDE (Integrated Development Environment) is used to develop the SMA project and to write the code of each data processing algorithm. This paper presents the developed software architecture and describes the necessary steps to add new data processing algorithms to SMA in order to increase the processing capabilities of PAMELA devices.An example of basic damage index estimation using delay and sum algorithm is provided

Plant diversity patterns in neotropical dry forests and their conservation implications

This is the author accepted manuscript. The final version is available from American Association for the Advancement of Science via the DOI in this record.Seasonally dry tropical forests are distributed across Latin America and the Caribbean and are highly threatened, with less than 10% of their original extent remaining in many countries. Using 835 inventories covering 4660 species of woody plants, we show marked floristic turnover among inventories and regions, which may be higher than in other neotropical biomes, such as savanna. Such high floristic turnover indicates that numerous conservation areas across many countries will be needed to protect the full diversity of tropical dry forests. Our results provide a scientific framework within which national decision-makers can contextualize the floristic significance of their dry forest at a regional and continental scale.This paper is the result of the Latin American and Caribbean Seasonally Dry Tropical Forest Floristic Network (DRYFLOR), which has been supported at the Royal Botanic Garden Edinburgh by a Leverhulme Trust International Network Grant (IN-074). This work was also supported by the U.K. Natural Environment Research Council grant NE/I028122/1; Colciencias Ph.D. scholarship 529; Synthesys Programme GBTAF-2824; the NSF (NSF 1118340 and 1118369); the Instituto Humboldt (IAvH)–Red colombiana de investigación y monitoreo en bosque seco; the Inter-American Institute for Global Change Research (IAI; Tropi-Dry, CRN2-021, funded by NSF GEO 0452325); Universidad Nacional de Rosario (UNR); and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). The data reported in this paper are available at www.dryflor.info. R.T.P. conceived the study. M.P., A.O.-F., K.B.-R., R.T.P., and J.W. designed the DRYFLOR database system. K.B.-R. and K.G.D. carried out most analyses. K.B.-R. R.T.P., and K.G.D. wrote the manuscript with substantial input from A.D.-S., R.L.-P., A.O.-F., D.P., C.Q., and R.R. All the authors contributed data, discussed further analyses, and commented on various versions of the manuscript. K.B.-R. thanks G. Galeano who introduced her to dry forest research. We thank J. L. Marcelo, I. Huamantupa, C. Reynel, S. Palacios, and A. Daza for help with fieldwork and data entry in Peru

Functionalized adsorbent materials using supercritical CO2

La silica (SiO2) porosa es uno de los adsorbentes históricamente más utilizado a nivel industrial en multitud de procesos. Sin embargo, el crecimiento acelerado de la demanda de nuevos materiales basados en nanotecnología y de nuevos procesos límpios y sostenibles ha hecho necesario el desarrollo de adsorbentes con nuevas o mejores propiedades fisico-químicas. Una de las opciones más empleadas para modificar la silica porosa es la incorporación de moléculas orgánicas con grupos funcionales dando lugar a materiales híbridos en los que se combinan las propiedades de ambos componentes. En esta tesis doctoral, se ha optado por el uso de dióxido de carbono supercrítico (scCO2) como disolvente para llevar a cabo ésta funcionalización. Estos procesos supercríticos, diseñados como sostenibles, actúan como sustitutos de técnicas convencionales que emplean disolventes orgánicos. En esta tesis se ha trabajado principalmente con matrices de sílica amorfa de poros structuralmente ordenados (MCM-41, 4 nm) y de poros desordenados (silica gel, 4-9 nm), analizándose sólo marginalmente las propiedades conferidas mediante la funcionalización a matrices cristalinas microporosas tipo zeolitas. Como agentes funcionalizantes, se han estudiado alkyl- y aminosilanos (octiltrietoxisilano y (methylamino)propyltrimethoxysilane ) y la aziridina que mediante una reacción de polimerización catalizada por CO2 forma la polietilenimina (PEI) dentro de los poros de la sílica, dando lugar a una red polimérica hiper-ramificada de grupos amino. Se trata de un método novedoso que únicamente requiere CO2 comprimido como reactivo y catalizador de la reacción de polimerización de la aziridina, que habitualmente requiere el empleo de disolventes orgánicos, catalizadores sólidos, altas temperaturas y largos tiempos de reacción. La funcionalización de silica porosa con aminosilanos en scCO2 es de mayor complejidad que en el caso de los alquilsilanos, ya que la alta reactividad entre los grupos amino y el CO2 da lugar a la formación de carbamatos insolubles en scCO2. Sin embargo, la reacción de formación de carbamatos pudo ser parcialmente inhibida mediante el control de la presión y la temperatura del medio de reacción. Los materiales obtenidos se han caracterizado mediante técnicas de estado sólido: adsorción de N2 a baja temperatura, análisis térmico, espectroscopia de infrarojo, método de tritación de Karl-Fischer, difracción de rayos X, espectrometría de masas por MALDI-ToF y difracción de luz estática. No obstante, también se han empleado técnicas de modelado y simulación molecular como herramientas complementarias, que permiten el estudio de estos sistemas de adsorción complejos con mayor nivel de detalle. La cadena alquílica del alkylsilano confiere al sistema poroso propiedades hidrofóbicas, preparándose de esta manera materiales útiles en la adsorción de aceites. La funcionalización con moléculas orgánicas que presentan el grupo amino ha permitido la preparación de materiales utilizados en procesos de adsorción y separación de CO2 en mezclas diluidas de gases (secuestro de CO2). Las propiedades adsorbentes de CO2 de las aminosílicas sintetizadas han sido evaluadas combinando técnicas experimentales de adsorción con simulaciones moleculares. La caracterización de estos materiales se basa en la evaluación de propiedades tales como la capacidad total de adsorción de CO2 y la influencia de la temperatura, la selectividad en la adsorción de CO2 en mezclas de gases, la estabilidad en la adsorción/desorción por ciclos y las cinéticas de estos procesos que han sido determinadas mediante tanto medidas termogravimétricas como mediante isotermas de adsorción de CO2 a diferentes temperaturas.Historically, porous silica (SiO2) is one of the most used adsorbents for a wide variety of processes in the industry. However, the fast grown on the demand of new nanotechnology based materials and sustainable green processes have made necessary the development of adsorbents with improved physico-chemical properties. One of the most applied options to modify porous silica is the incorporation on the surface of organic functional molecules, giving place to hybrid materials, in which the properties of both components are combined. In this doctoral thesis, supercritical carbon dioxide (scCO2) has been used as the solvent to carry out the functionalization processes. Carbon dioxide is a sustainable solvent and its use has been preferred in front of toxic organic liquid solvents, often applied in the traditional methods of synthesis. Amorphous silica matrices with structural ordered pores (MCM-41, 4 nm) and disordered pores (silica gel, 4-9 nm) were selected for the functionalization processes. Besides, the properties conferred by functionalization to microporous crystaline zeolites have been preliminary studied. The modifying agents applied in this thesis were either alkyl (octyltriethoxysialane) or amino (methylaminopropyltrimethoxisilane) silane and aziridine. The later compound is a monomer which polymerizes in presence of CO2, leading to hyperbranched polyethyleneimine (PEI) with multiple amino groups formed into the silica pores. This novel method only requires compressed CO2 as the reagent and the catalyst of the polymerization reaction of aziridine, which usually requires the use of organic solvents, a solid catalyst, high temperatures and long processing times. The functionalization of porous silica with aminosilane in scCO2 is more complex than the case of alkysilanes due to the high reactivity between amino groups and CO2 to form unsoluble carabamate species. However, in this study a protocol was designed to partially inhibit carabamate formation by controlling the pressure and temperature of the reaction media. The obtained materials were characterized using solid state characterization tools: low temperature N2 and CO2 adsorption, thermal analysis, infrared spectroscopy and X-Ray diffraction. Moreover, modeling and simulation methods were used as complementary tools that allowed the study of this complex systems with a high level of detail. The alkyl chain of the alkylsilane induced to the porous system a hydrophobic behavior, hence, obtaining materials candidates for oil adsorption. The functionalization with organic molecules containing the amino group allowed the preparation of materials for the adsorption and separation of CO2 from diluted gases (CO2 sequestration). The CO2 adsorption properties of the synthesized aminosilicas were evaluated combining experimental adsorption tools with molecular simulations. The characterization of these materials was based on the evaluation of the overall CO2 adsorption capacity and the influence of the temperature, the selectivity of the CO2 adsorption in gas mixtures, the stability in the cyclic adsorption/desorption process and the kinetics, which were determined by performing both microbalance and CO2 adsorption isotherms at different temperatures

Designing Spinel Li₄Ti₅O₁₂ Electrode as Anode Material for Poly(ethylene)oxide-Based Solid-State Batteries

The development of a promising Li metal solid-state battery (SSB) is currently hindered by the instability of Li metal during electrodeposition; which is the main cause of dendrite growth and cell failure at elevated currents. The replacement of Li metal anode by spinel Li4Ti5O12 (LTO) in SSBs would avoid such problems, endowing the battery with its excellent features such as long cycling performance, high safety and easy fabrication. In the present work, we provide an evaluation of the electrochemical properties of poly(ethylene)oxide (PEO)-based solid-state batteries using LTO as the active material. Electrode laminates have been developed and optimized using electronic conductive additives with different morphologies such as carbon black and multiwalled carbon nanotubes. The electrochemical performance of the electrodes was assessed on half-cells using a PEO-based solid electrolyte and a lithium metal anode. The optimized electrodes displayed an enhanced capability rate, delivering 150 mAh g−1 at C/2, and a stable lifespan over 140 cycles at C/20 with a capacity retention of 83%. Moreover, postmortem characterization did not evidence any morphological degradation of the components after ageing, highlighting the long-cycling feature of the LTO electrodes. The present results bring out the opportunity to build high-performance solid-state batteries using LTO as anode material

Coalescence of lateral spreading magma ascending through dykes: a mechanism to form a granite canopy (El Hongo pluton, Sierras Pampeanas, Argentina)

This study deals with the structure of the El Hongo trondhjemite, a ENE–WSW elongate pluton belonging to the Famatinian magmatic arc that developed from Late Cambrian to Silurian times in the Sierras Pampeanas (Argentina). Anisotropy of magnetic susceptibility (AMS) measurements combined with structural and microstructural data permit the correlation of magmatic and magnetic fabrics within this ferromagnetic pluton. Magnetic foliations strike north–south and dip steeply west but in the marginal facies the foliation becomes parallel to the ENE–WSW pluton contacts. Magnetic lineations mostly trend north–south and plunge SE. Gravity data reveal that the pluton is in the form of a very thin horizontal sheet resting on two north–south-trending root zones detected below the central portion of the pluton. These root zones represent feeder dykes that exploited tension fractures. The emplacement of the El Hongo pluton took place during the action of a buried sinistral shear zone, parallel to the elongation of the pluton, corresponding to a transfer fault associated with the late extensional exhumation of the Famatinian domain. The emplacement of other Famatinian granites of the Sierras Pampeanas could be related to similar late shear zones

Functionalized adsorbent materials using supercritical CO2

Premi Extraordinari de Doctorat concedit pels programes de doctorat de la UAB per curs acadèmic 2017-2018La silica (SiO2) porosa es uno de los adsorbentes históricamente más utilizado a nivel industrial en multitud de procesos. Sin embargo, el crecimiento acelerado de la demanda de nuevos materiales basados en nanotecnología y de nuevos procesos límpios y sostenibles ha hecho necesario el desarrollo de adsorbentes con nuevas o mejores propiedades fisico-químicas. Una de las opciones más empleadas para modificar la silica porosa es la incorporación de moléculas orgánicas con grupos funcionales dando lugar a materiales híbridos en los que se combinan las propiedades de ambos componentes. En esta tesis doctoral, se ha optado por el uso de dióxido de carbono supercrítico (scCO2) como disolvente para llevar a cabo ésta funcionalización. Estos procesos supercríticos, diseñados como sostenibles, actúan como sustitutos de técnicas convencionales que emplean disolventes orgánicos. En esta tesis se ha trabajado principalmente con matrices de sílica amorfa de poros structuralmente ordenados (MCM-41, 4 nm) y de poros desordenados (silica gel, 4-9 nm), analizándose sólo marginalmente las propiedades conferidas mediante la funcionalización a matrices cristalinas microporosas tipo zeolitas. Como agentes funcionalizantes, se han estudiado alkyl- y aminosilanos (octiltrietoxisilano y (methylamino)propyltrimethoxysilane ) y la aziridina que mediante una reacción de polimerización catalizada por CO2 forma la polietilenimina (PEI) dentro de los poros de la sílica, dando lugar a una red polimérica hiper-ramificada de grupos amino. Se trata de un método novedoso que únicamente requiere CO2 comprimido como reactivo y catalizador de la reacción de polimerización de la aziridina, que habitualmente requiere el empleo de disolventes orgánicos, catalizadores sólidos, altas temperaturas y largos tiempos de reacción. La funcionalización de silica porosa con aminosilanos en scCO2 es de mayor complejidad que en el caso de los alquilsilanos, ya que la alta reactividad entre los grupos amino y el CO2 da lugar a la formación de carbamatos insolubles en scCO2. Sin embargo, la reacción de formación de carbamatos pudo ser parcialmente inhibida mediante el control de la presión y la temperatura del medio de reacción. Los materiales obtenidos se han caracterizado mediante técnicas de estado sólido: adsorción de N2 a baja temperatura, análisis térmico, espectroscopia de infrarojo, método de tritación de Karl-Fischer, difracción de rayos X, espectrometría de masas por MALDI-ToF y difracción de luz estática. No obstante, también se han empleado técnicas de modelado y simulación molecular como herramientas complementarias, que permiten el estudio de estos sistemas de adsorción complejos con mayor nivel de detalle. La cadena alquílica del alkylsilano confiere al sistema poroso propiedades hidrofóbicas, preparándose de esta manera materiales útiles en la adsorción de aceites. La funcionalización con moléculas orgánicas que presentan el grupo amino ha permitido la preparación de materiales utilizados en procesos de adsorción y separación de CO2 en mezclas diluidas de gases (secuestro de CO2). Las propiedades adsorbentes de CO2 de las aminosílicas sintetizadas han sido evaluadas combinando técnicas experimentales de adsorción con simulaciones moleculares. La caracterización de estos materiales se basa en la evaluación de propiedades tales como la capacidad total de adsorción de CO2 y la influencia de la temperatura, la selectividad en la adsorción de CO2 en mezclas de gases, la estabilidad en la adsorción/desorción por ciclos y las cinéticas de estos procesos que han sido determinadas mediante tanto medidas termogravimétricas como mediante isotermas de adsorción de CO2 a diferentes temperaturas.Historically, porous silica (SiO2) is one of the most used adsorbents for a wide variety of processes in the industry. However, the fast grown on the demand of new nanotechnology based materials and sustainable green processes have made necessary the development of adsorbents with improved physico-chemical properties. One of the most applied options to modify porous silica is the incorporation on the surface of organic functional molecules, giving place to hybrid materials, in which the properties of both components are combined. In this doctoral thesis, supercritical carbon dioxide (scCO2) has been used as the solvent to carry out the functionalization processes. Carbon dioxide is a sustainable solvent and its use has been preferred in front of toxic organic liquid solvents, often applied in the traditional methods of synthesis. Amorphous silica matrices with structural ordered pores (MCM-41, 4 nm) and disordered pores (silica gel, 4-9 nm) were selected for the functionalization processes. Besides, the properties conferred by functionalization to microporous crystaline zeolites have been preliminary studied. The modifying agents applied in this thesis were either alkyl (octyltriethoxysialane) or amino (methylaminopropyltrimethoxisilane) silane and aziridine. The later compound is a monomer which polymerizes in presence of CO2, leading to hyperbranched polyethyleneimine (PEI) with multiple amino groups formed into the silica pores. This novel method only requires compressed CO2 as the reagent and the catalyst of the polymerization reaction of aziridine, which usually requires the use of organic solvents, a solid catalyst, high temperatures and long processing times. The functionalization of porous silica with aminosilane in scCO2 is more complex than the case of alkysilanes due to the high reactivity between amino groups and CO2 to form unsoluble carabamate species. However, in this study a protocol was designed to partially inhibit carabamate formation by controlling the pressure and temperature of the reaction media. The obtained materials were characterized using solid state characterization tools: low temperature N2 and CO2 adsorption, thermal analysis, infrared spectroscopy and X-Ray diffraction. Moreover, modeling and simulation methods were used as complementary tools that allowed the study of this complex systems with a high level of detail. The alkyl chain of the alkylsilane induced to the porous system a hydrophobic behavior, hence, obtaining materials candidates for oil adsorption. The functionalization with organic molecules containing the amino group allowed the preparation of materials for the adsorption and separation of CO2 from diluted gases (CO2 sequestration). The CO2 adsorption properties of the synthesized aminosilicas were evaluated combining experimental adsorption tools with molecular simulations. The characterization of these materials was based on the evaluation of the overall CO2 adsorption capacity and the influence of the temperature, the selectivity of the CO2 adsorption in gas mixtures, the stability in the cyclic adsorption/desorption process and the kinetics, which were determined by performing both microbalance and CO2 adsorption isotherms at different temperatures

Spatially Offset Raman Spectroscopy for Characterization of a Solid-State System

Solid-state batteries represent a promising technology in the field of high-energy-density and safe storage systems. Improving the understanding of how defects form within these cells would greatly facilitate future development, which would be best served by applying nondestructive analytical tools capable of characterization of the key components and their changes during cycling and/or aging. Spatially offset Raman spectroscopy (SORS) represents a potentially useful technique, but currently there is a lack of knowledge regarding its use in this field. To fill this gap, we present an investigation into the use of simple defocused micro-SORS on systems constructed using typical components found within solid-state cells. By analyzing the constituents and the assembled system, it was possible to obtain depth profiling spectra and show that spectra may be obtained from layers which are normally obscured, demonstrating the technique’s potential for nondestructive chemical analysis of the subsurface. In this way, the results presented validate the potential of micro-SORS as a technique to develop to support future solid-state battery development, as well as the nondestructive battery analytical field