This work is aimed to design power supply for nodes of wireless sensors networks using solar energy in indoor spaces. The proposal is made for the particular layout, but the process described can be applied generally. The result is the proposed involvement of the operating power circuit for node of wireless sensor network used indoors.

The talk will discuss recent synthesis strategies to oxides and carbons with 3-D architecture and will try to evaluate the advantages, challenges and perspectives of such materials for Li ion insertion and diffusion in view of improved performance in battery systems.

Performance degradation of lithium-ion batteries (LIBs) from in-service abuse was analyzed using novel dynamic abuse tests and sensor-based in-situ monitoring of battery state of health (SOH). The relation between dynamic impact and structure changes of LiCoO₂ (LCO) electrode was analyzed through a nano-impact test directly applied to the electrode and Raman imaging. After the electrode structure damage induced by the dynamic loading was analyzed, the performance of the LIBs with the abused electrodes was evaluated to establish the relation between the number of impact cycles and LIB performance degradation. The mechanism of impact related LIB capacity decrease was analyzed, and the capacity change can be predicted based on the impact abuse history using this approach. In order to provide more detailed information on the battery performance degradation caused by the in-service dynamic loads, a dynamic aging testing platform was designed to simulate in-service vibration and impact experienced by the LIBs. Based on the lessons learned, a sensor network was constructed to provide a comprehensive in-situ evaluation of the SOH of commercial batteries. Mechanisms of LIB capacity fade, temperature increase, and cell deformation from cycling in representative dynamic environments were analyzed and correlated with theoretical predictions. Difference between the aging of a battery pack and that of a single cell was also investigated, which presented the influence of current imbalance on the SOH decay of battery packs. SEM imaging, Raman imaging, and electrochemical impedance spectroscopy (EIS) analysis were also applied to support the sensor network measurements.<br><div> In order to provide an early detection of catastrophic LIB failure such as thermal runaway, an internal resistance temperature detector (RTD) based electrode temperature monitoring approach was developed. By embedding the RTD into LIBs with 3D printing technique, electrode temperature can be collected during ordinary cycling and electrical abuse of LIBs, such as external short circuit and overcharge. The internal RTD presented high measuring efficiency, while there was no interference between the sensor measurement and battery operation. The internal RTD detected the short circuit event and overcharge failure prior of time: the efficiency of the internal RTD was 6-10 times higher than the external RTD in the short circuit test. This provided the chance for early detection and prevention of catastrophic LIB failures. Besides, with the detailed information on electrode temperature evolution during LIB thermal runaway available, the internal RTD also provided the chance to enhance the understanding of the thermal runaway mechanism.</div>

<div>Electrochemical energy storage devices play an integral role in the energy transition from fossil fuels to renewable. Still, technological breakthroughs are warranted to expand this progress and enable their use where hydrocarbons are still the dominant option. The requirements restricting further adoption of electrochemical devices are related to energy density, hampering costs of raw materials with the increased global demand, and safety in large scale operations. Furthermore, new applications in flexible electronics add new requisites to this list. Pushing these limits involves multidisciplinary efforts where the mechanics are a crucial part.</div><div> </div><div>This thesis explores the mechanical and kinetic behaviors of batteries at the nano to micro-meter scale through operando mechanical and optical characterization during ongoing electrochemical reactions. A unique experimental platform that enables simultaneous nanoindentation and electrochemical testing of active materials is developed. The validity of mechanical testing during operation in the customized liquid cell is systematically addressed. The evolution of the mechanical properties of electrodes as a function of lithium concentration is probed in real-time. This functional dependence between mechanical properties and composition is then used to introduce the concept of mechanics-informed chemical profiling. This new capability enables characterizing transport kinetics in a detailed and quantitative way, including the role of pressure gradients on diffusion. Pairing these experiments with multi-physics modeling led to a new understanding of the mechanisms regulating charging-rate capability and capacity loss in Li-ion batteries. Experiments on composite electrodes showed that liquid electrolytes change the mechanical properties of both conductive matrix and secondary particles. These observations help understand the interactions between the different components of a battery and demonstrate the need for in-situ mechanical characterization capabilities. </div>

Moderna företag inom nyhetsindustrin samlar stora mängder data för att evaluera effektiviteten av sin dagliga verksamhet, förbättra kundvärdet och fatta långsiktiga, strategiska beslut. Multimedia och datormolnets framfart under de senaste åren har lett till stora omvandlingar av hela nyhetsindustrin, men de ledande affärsmodellerna har varit långsamma på att anpassa sig till de nya förhållandena. En fallstudie har utförts hos ett digitalt nyhetsmedieföretag med säte i Stockholm. Vi har utvecklat ett verksamhetsutvecklingsverktyg i Java som samlar stora mängder mätdata och sammanställer detta i en databas. Det ska gå att visualisera och plotta data som en användare väljer genom att kommunicera med databasen. Vi använder vårt verktyg för att skapa och utveckla affärsmodeller som håller givet de förhållanden som råder inom industrin. Vi ger förslag på hur de strategiska målen kan nås genom att skapa ett balanserat styrkort med nyckeltal vi sammanställer från vårt verktyg. Våra resultat indikerar på att mått på användarbehållande, värde till användare och nyhetsleverantörer, och bidrag till välgörenhetsorganisationer som agerar via företaget är några av de viktigare nyckeltalen för att tillfredsställa de nuvarande strategiska målen. Vi ger råd om hur de strategiska målen för företaget ska nås genom att skapa ett balanserat styrkort med nyckeltal som vi bygger med hjälp av vår applikation. Våra resultat tyder på att företaget ska fokusera på att behålla befintliga användare och tydliggöra värdeskapandet till användare, nyhetsleverantörer och annonsörer. För att uppnå detta föreslår vi nya typer av tjänster som företaget ska tillhandahålla. / Modern companies in the news industry gather large quantities of data in order to evaluate the efficiency of their daily operations, to enhance customer value and make long-term, strategic decisions. With the rise of multimedia and cloud computing, the industry itself has transformed over the years, but the leading business models are slow to adapt to this change. At the same time, with technology becoming more of a commodity, companies are putting less emphasis on leveraging technology to a competetive edge, instead opting for stronger, more complex business models to create superior value. This thesis aims to link together valuable data measured by companies, with the creation of strong business models and strategic goals. A case study was performed at a Swedish digital news media startup based in Stockholm. We develop a business intelligence tool in Java that gathers large amounts of raw data, compiles the data into a database, and enables visualisation and plotting of selected data by performing query runs on the database. We use this application to develop and enhance business models that is viable in the current state of the industry. We give advise on how to reach the strategic goals of the company by creating a balanced scorecard with key performance indicators that we develop using our application. Our results indicate that the company should focus on user retention and increase its value proposition to users, news providers and advertisers. We will propose new types of services that the company should provide in order to accomplish this.

Next-generation batteries with improved microstructure and performance are on their way to meet the market demands for high-energy and power storage systems. Among different types of batteries, Li-ion batteries remain the best choice for their high energy density and long lifetime. There is a constant but slow improvement in Li-ion batteries by developing new materials and fabrication techniques. However, further improvements are still needed to meet government and industry goals for cost, cycling performance, and cell lifetime. A fundamental understanding of particle-level interactions can shed light on designing new porous electrodes for high-performance batteries. This is a complex problem because electrodes have a multi-component, multi-phase microstructure made through multiple fabrication processes (i.e., mixing, coating, drying, and calendering). Each of these processes can affect the final microstructure (particle and pore locations) differently. This work seeks to understand the porous microstructure evolution of Li-ion electrodes during the drying and calendering fabrication processes by a combination of modeling and experimental approaches. The goal is to understand the mechanisms by which the electrode components and fabrication processes determine the battery microstructure and subsequent cell performance. A multi-phase smoothed particle (MPSP) model has been developed on a publically available simulation platform known as LAMMPS. This model was used to simulate particle-level interactions and predict the mechanical and transport properties of four fabricated electrodes (i.e. a graphite anode and three traditional metal oxide cathodes). One challenge was to include different electrode components and their interactions and relate them to physical properties like density and viscosity that can be measured experimentally. Another challenge was to generate required electrode property data for model validation, which in general was not found in the literature. Therefore, a series of experiments were conducted to provide that information, namely slurry viscosity, electronic conductivity, porosity, tortuosity, elastic modulus, and electrode crosssections. Understanding these properties has value to the battery community independent of their use in this study. The MPSP model helps us explain observed transport heterogeneity after calendering but brings up new questions about the drying process that have not been addressed in previous works. Therefore, the drying fabrication step was studied experimentally in more detail to fill this knowledge gap and explain our simulation results. The MPSP model can also be used as a predictive tool to explore the design space of Li-ion electrodes where conducting the actual experiments is very challenging. For example, the distinct effect of particle size, shape, orientation, and stiffness on electrode transport and mechanical properties are difficult to determine independently, and therefore this model is an ideal tool to understand the effect of these properties. The final model, which is publically available, could be used with adjustments by future workers to test new materials, fabrication processes, or electrode design (e.g., a multi-layered structure).

Rechargeable lithium-ion batteries are a staple of modern society, providing power to a significant portion of the world's electronics and rapidly replacing older power sources. The advent of widely available electric cars with batteries of up to 200 kWh, with an increasing emphasis on fast charging, has only increased their importance. Lithium-ion battery electronic and ionic properties are largely determined by the microstructure of the battery electrode film and can be heavily influenced by relatively small variations in film makeup, including the formation of voids or distribution of carbon and binder. Prior to this research, electrical properties, which are some of the most important characteristics to battery cost, performance, and safety, were either difficult or, in the case of contact resistance, impossible to directly measure. This dissertation focuses on the development and use of a micro-surface probe for measurement and mapping of lithium-ion battery film electronic characteristics. The measurement apparatus, inversion and mapping routines, and experimental data presented provide manufacturers and researchers with a better understanding of battery heterogeneity and the influence of microstructure on electrical properties. The micro-surface probe was used to map spatial variation on both a macro and micro scale; compare physical, electrical, and ionic properties; and validate tests that were previously used to estimate electronic parameters. Experiments on commercial-quality battery electrode films showed higher micro-heterogeneity than was previously assumed by a significant margin. Additionally, electronic and ionic properties were shown to not always be inversely related and some physical explanations for observed variation were explored. Macro-variations were measured and shown to exist across electrode films which were previously assumed to be uniform. Finally a comparison to the mechanical peel test, a common test used in industry as a proxy measurement of electrical contact resistance, proved the peel test to be inconclusive and showed that it will not always accurately reflect electrical properties of films. Direct measurements of both electrical conductivity and contact resistance provide a new and important tool to advance understanding and development of lithium-ion batteries. The magnitude of the measured resistivities and their significant variation demonstrates that a better understanding of film properties is needed and will significantly influence our understanding of modern battery parameters and the effects of manufacturing techniques on battery performance.

El acelerado crecimiento del mercado de Aparatos Eléctricos y Electrónicos (AEE), la obsolescencia programada y el aumento del descarte de los Residuos de Aparatos Eléctricos y Electrónicos (RAEE) están generando impactos socioambientales en todo el mundo. Los RAEE contienen substancias tóxicas, que aumentan los riesgos para la salud y el medioambiente. La gestión de dichos residuos ha motivado a varios países a reflexionar sobre los prerrequisitos para la gestión de RAEE de forma ambientalmente saludable, a través de la Logística Inversa (LI) de RAEE. Europa surge en el escenario mundial como ejemplo en la implementación de la LI de RAEE debido a los modelos de alto desempeño, que revelan varios factores en común. Trabajo conjunto, compromiso de los consumidores, intercambio de información, leyes claras, con roles bien definidos, esfuerzos coordinados de los actores de la LI para alcanzar los mismos objetivos. Tales elementos de comportamiento cooperativos y colaborativos entre los actores da LI de RAEE pueden explicar en parte el éxito de algunos europeos. El acelerado crecimiento del mercado de Aparatos Eléctricos y Electrónicos (AEE), la obsolescencia programada y el aumento del descarte de los Residuos de Aparatos Eléctricos y Electrónicos (RAEE) están generando impactos socioambientales en todo el mundo. Los RAEE contienen substancias tóxicas, que aumentan los riesgos para la salud y el medioambiente. La gestión de dichos residuos ha motivado a varios países a reflexionar sobre los prerrequisitos para la gestión de RAEE de forma ambientalmente saludable, a través de la Logística Inversa (LI) de RAEE. Europa surge en el escenario mundial como ejemplo en la implementación de la LI de RAEE debido a los modelos de alto desempeño, que revelan varios factores en común. Trabajo conjunto, compromiso de los consumidores, intercambio de información, leyes claras, con roles bien definidos, esfuerzos coordinados de los actores de la LI para alcanzar los mismos objetivos. Tales elementos de comportamiento cooperativos y colaborativos entre los actores da LI de RAEE pueden explicar en parte el éxito de algunos europeos. En este contexto, es esencial entender la distinción entre cooperación y colaboración para proyectar políticas que faciliten las relaciones de trabajo conjunto entre los actores de la cadena inversa de RAEE. Sin embargo, pocas investigaciones hacen la diferenciación de estos conceptos, y casi ninguna se ha dedicado a entender el impacto de la colaboración y cooperación en la implementación de la LI de RAEE. Además, países en desarrollo como Brasil han enfrentado muchos obstáculos para implementar la LI de RAEE. Esta investigación buscó entender cómo la colaboración y la cooperación están influenciando la implementación del modelo de LI de RAEE en el escenario europeo y en el brasileño. Para ello, esta investigación tuvo un enfoque cualitativo, exploratorio y descriptivo, ya que su objetivo es entender lo que motiva a los actores a implementar la LI de RAEE y cómo la colaboración y cooperación tienen impacto sobre su resultado. La recolección de datos fue hecha por medio de estudios de caso múltiples, entrevistas en profundidades semiestructuradas, aplicadas a los principales drivers de la LI de RAEE en Brasil, España, Portugal y Suiza. El análisis de los datos usó la técnica de análisis de contenido. Los resultados muestran que, aplicando la matriz de los atributos de determinantes de colaboración y cooperación, elaborada a partir del marco teórico, en los cuatro países estudiados, aquellos que presentaron el mayor número de conformidades con el modelo propuesto fueron también los que registraron mayor eficiencia en sus sistemas de LI. Además, se puede inferir que atributos motivacionales como predisposición e histórico en trabajos conjuntos aumentan positivamente el impacto de la colaboración o cooperación en la LI de RAEE. También se notó que la obligatoriedad de hacer algo, solo por fuerza de ley, no estimula a los actores a superar las metas exigidas, aunque sea una motivación importante, principalmente si ésta es externa, como es el caso de la Directiva europea de RAEE. En ese escenario, sin ninguna no conformidad y con predisposición para el trabajo conjunto para solucionar desafíos socioambientales, Suiza es el país con el mejor resultado en la recogida de RAEE. En segundo lugar está Portugal con 1 no conformidad en la dimensión Estructura y la necesidad de atender a la Directiva como principal factor motivacional. España sigue al modelo portugués, con igual necesidad de atender a la legislación externa, pero con 1 no conformidad en motivación, ya que no se sentía obligada a cumplir con las metas hasta el 2019. Por otro lado, Brasil registró el mayor número de no conformidades con la matriz propuesta. Se destaca, en el caso brasileño, la falta de motivación en colaborar, de parte de todos los actores de la cadena inversa, lo que explica los pocos avances registrados tras 8 años de aprobación de la PNRS. La matriz propuesta ayuda también a identificar elementos de la estructura operacional que favorezcan procesos de colaboración y cooperación en el modelo brasileño de LI, de modo de contribuir con impactos positivos.

The present talk will briefly summarize our activities in the FOR 1277 “Mobility of Li Ions in Solids” (molife) thankfully funded by the DFG.

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