Målet med projektet var att undersöka samt implementera en fysikbaserad DFN modell för att simulera kalender samt cyklingåldrande av litiumbatterier som används i elbilar. Den fysikbaserade modellen var konstruerad baserad på ett Python biblioteket vid namn PyBaMM, vilket till skillnad från datadrivna modeller ger essentiell information om de kemiska processerna inuti batteriet. Den första delen av projektet täcker konceptet av kalenderåldring, vilket inkluderar en jämförelse mellan tre olika tre olika hastighetsbegränsande SEI modeller. Parametrar som påverkar det erhållna resultatet från modellen är identifierade, estimerade, och till slut validerade för att säkerhetsställa att modellen och parametrarna är identifierbara gentemot experimentella data. Resultatet av jämförelsen gav att SEI tillväxt begränsad av litium interstitiell diffusion är den mest optimala modellen att applicera när kalenderåldring för litiumbatterier ska modelleras. Resultaten visade också att endast en parameter, inre SEI litium interstitiell diffusivitet ska justeras för att erhålla optimal anpassning mot experimentella data. Andra delen av projektet använde resultatet från den första delen och litium plätering implementerades som en andraåldringsmekanism som undersöktes under tre olika laddningsprotokoll. Modellen var optimerad och anpassad gentemot experimentella data, där parametervärdet för kinetisk hasighetskonstanten för plätering var estimerad. Den optimerade modellen användes därefter för att erhålla mer information om elektrokemiska variabler för att kunna analysera samt beskriva åldringsprocessen utan att behöva genomföra praktiska laborationer. Resultaten visade att mängden pläterat litium på den negativa elektroden ökade för celler som var exponerade till högre ström under laddningsprocessen, samt när cellerna var laddade vid höga SoC nivåer. Sammanfattningsvis, visade modellen hög potential att representera och evaluera experimentella data, samt tillhandahålla en inblick i elektrokemiska processer och kapacitetsförluster länkade till SEI tillväxt och litium plätering. Däremot, för att erhålla en högre grad noggrannhet av elektrokemiska åldringsmekanismer i litiumbatterier, fler ytterligare mekanismer måste implementeras såsom mekanisk stress av både negativ och positiv elektrod. / The aim of this study was to investigate and apply a physics-based DFN model to simulate the calendar and cycling ageing of lithium-ion batteries manufactured for EV applications. The physics-based cell ageing model was constructed based on the open-source software Python library PyBaMM, which in comparison to data-driven models provides more essential information about the chemical process within the battery cell. The first part of the project covers the concept of calendar ageing which includes comparisons between three different rate-limiting SEI growth models. Parameters that affect the output from the physics-based model are isolated, estimated with numerical methods, and lastly validated to ensure that the model and the parameters rep- resent the physics behind the experimental data. It was found that the SEI growth limited by lithium interstitial diffusion is the most optimal model to apply for a physics-based model when modeling calendar ageing. It was also found that the only parameter that should be tuned against experimental data is the inner SEI lithium interstitial diffusivity. The second part of the project utilizes the results from the first part and introduces lithium plating as a second cell ageing mechanism under three different charging protocols. The model was optimized and fitted against experimental data by sweeping the lithium plating kinetic rate constant parameter. The optimized model was thereafter used to generate outputs that more thoroughly can explain the degradation effects of the cell without constructing real-world experiments. Where increased rate of plated lithium could be observed for the cell subjected to higher charging C-rate, and when the cells were charged at high SoC levels. To summarize, the model showed great potential in representing and evaluating the experimental data and providing the project with insight into the electrochemical processes and cell capacity losses of SEI growth and lithium plating. However, in order to achieve a higher accuracy of cell ageing model in relation to the lithium-ion cells used in customer vehicles, several additional cell degradation mechanisms have to be introduced, such as mechanical degradation of the two electrodes.

This thesis proposes that a defining feature of Pirandello???s 1921 play ??? Six Characters in Search of an Author, is a relentless transcendentalism. It argues that the play embodies a fascination with existential and conceptual ???occult???, and my hypothesis is that by exploring Pirandello's transcendentalism we may enhance our understanding of how and why Pirandello's play points a mirror up to the invisible and suggests that we could be a reflection of that. Pirandello's drama alludes to some of the most convoluted and enduring debates in western philosophy. However, there is very little English-language material on Pirandello???s relation to philosophy or the relevance of analytical philosophy, metaphysics or epistemology to Pirandello???s playwriting. Even foreign-language studies focus on existentialism, phenomenology and other Continental traditions of philosophy. My contribution is to craft a subjective response to Six Characters in accordance with the methods of analytical philosophy, making use of paradigms and techniques that stem from aesthetics and metaphysics to elucidate a complex self-reflexive play. Chapter One presents analytical philosophy as a potential interpretative framework for the play, whereas chapters two and three explore the metacharacters specifically. This thesis does not seek to offer conclusive assertions about the peculiar ontological status of Pirandello???s metacharacters, rather, it introduces some frameworks and conceptual tools for better approaching their ontolo

Les batteries à électrode lithium métal ont des capacités théoriques élevées, une différence de potentiel importante, des géométries adaptables. Leur développement à l'échelle industrielle est pourtant compromis par l'électrodépôt d'agrégats irréguliers de lithium (dendrites) lors de la recharge de la batterie. La croissance dendritique à faible densité de courant est mal comprise, et semble liée à une mauvaise distribution de la densité de courant locale du fait des inhomogénéités à l'interface lithium/électrolyte. Ce manuscrit présente nos résultats sur des cellules symétriques Li/Electrolyte/Li qui permettent d'étudier simultanément le dépôt et la dissolution du lithium. Ces cellules sont basées sur des systèmes à base de POE+LiTFSI fonctionnant à 80°C, et sur des systèmes à base de PVdF-HFP/POE imbibé en EC:PC+LiTFSI et fonctionnant à température ambiante. Nous avons étudié ces cellules par visualisation in situ de l'espace inter-électrodes, et par spectroscopie d'impédance. Sur des cellules de visualisation à base d'électrolyte polymère fondu chargé en sel coloré, nous avons observé l'évolution des profils d'absorption optique directement liés aux profils de concentration dans l'électrolyte. Sur le système à base d'électrolyte gélifié nous avons constaté des variations locales de densité de courant en cours de polarisation. Par impédance, nous mettons en évidence la présence de deux couches de passivation à l'interface lithium/électrolyte qui évoluent différemment en vieillissement. Lorsqu'on polarise une cellule à courant constant, sa réponse en tension met en évidence la présence d'un milieu peu diffusif à l'interface entre le lithium et l'électrolyte.

The stability of electrode/electrolyte interfaces in Li-ion batteries is crucial to the performance, lifetime and safety of the entire battery system. In this work, interface processes have been studied in LiFePO4/graphite Li-ion battery cells.  The first part has focused on improving photoelectron spectroscopy (PES) methodology for making post-mortem battery analyses. Exposure of cycled electrodes to air was shown to influence the surface chemistry of the graphite. A combination of synchrotron and in-house PES has facilitated non-destructive interface depth profiling from the outermost surfaces into the electrode bulk. A better understanding of the chemistry taking place at the anode and cathode interfaces has been achieved. The solid electrolyte interphase (SEI) on a graphite anode was found to be thicker and more inhomogeneous than films formed on cathodes. Dynamic changes in the SEI on cycling and accumulation of lithium close to the carbon surface have been observed.    Two electrolyte additives have also been studied: a film-forming additive propargyl methanesulfonate (PMS) and a flame retardant triphenyl phosphate (TPP). A detailed study was made at ambient and elevated temperature (21 and 60 °C) of interface aging for anodes and cathodes cycled with and without the PMS additive. PMS improved cell capacity retention at both temperatures. Higher SEI stability, relatively constant thickness and lower loss of cyclable lithium are suggested as the main reasons for better cell performance. PMS was also shown to influence the chemical composition on the cathode surface. The TPP flame retardant was shown to be unsuitable for high power applications. Low TPP concentrations had only a minor impact on electrolyte flammability, while larger amounts led to a significant increase in cell polarization. TPP was also shown to influence the interface chemistry at both electrodes. Although the additives studied here may not be the final solution for improved lifetime and safety of commercial batteries, increased understanding has been achieved of the degradation mechanisms in Li-ion cells. A better understanding of interface processes is of vital importance for the future development of safer and more reliable Li-ion batteries.

This thesis proposes that a defining feature of Pirandello???s 1921 play ??? Six Characters in Search of an Author, is a relentless transcendentalism. It argues that the play embodies a fascination with existential and conceptual ???occult???, and my hypothesis is that by exploring Pirandello's transcendentalism we may enhance our understanding of how and why Pirandello's play points a mirror up to the invisible and suggests that we could be a reflection of that. Pirandello's drama alludes to some of the most convoluted and enduring debates in western philosophy. However, there is very little English-language material on Pirandello???s relation to philosophy or the relevance of analytical philosophy, metaphysics or epistemology to Pirandello???s playwriting. Even foreign-language studies focus on existentialism, phenomenology and other Continental traditions of philosophy. My contribution is to craft a subjective response to Six Characters in accordance with the methods of analytical philosophy, making use of paradigms and techniques that stem from aesthetics and metaphysics to elucidate a complex self-reflexive play. Chapter One presents analytical philosophy as a potential interpretative framework for the play, whereas chapters two and three explore the metacharacters specifically. This thesis does not seek to offer conclusive assertions about the peculiar ontological status of Pirandello???s metacharacters, rather, it introduces some frameworks and conceptual tools for better approaching their ontolo

abstract: This multilevel, institutional case study used ethnographic methods to explore the intersections of local language policies and emergent bilingual students’ identities in dual language and structured English immersion (SEI) classrooms at one urban elementary school. Using a sociocultural policy approach as means to explore the ways that educational language policies are appropriated and practiced in schools and classrooms and an intersectional literacy identity framework, I engaged in a multilevel qualitative analysis of one school, two fifth-grade classrooms, and four focal emergent bilingual students. At the school and classroom levels, I sought to understand the ways educators practiced and enacted language policies as well as how they conceptualized (bi)literacy for emergent bilingual students. At the student level, I engaged in identity-text writing sessions designed around student interests yet aligned with the opinion/argumentation writing style the students were working on in class at the time of data collection. Additionally, I conducted one-on-one interviews with the participants at each level of analysis (i.e. school-level, classroom-level, and student-level). The primary data analysis sources included participant interviews, classroom observations, and student identity-text artifacts. Findings highlight the dynamic in-school and classroom-level realities of emergent bilingual students in an Arizona educational-language policy context. Specifically, at the school level, there was an ongoing tension between compliance and resistance to state-mandated policies for emergent bilingual students. At the school and classroom levels, there were distinct differences in the ways students across the two classrooms were positioned within the larger school environment as well as variation surrounding how language and culture were positioned as a resource in each classroom context. The role of teachers as language policymakers is also explored through the findings. Analysis of student texts revealed the centrality of intersectional student identities throughout the writing processes. The discussion and conclusions more broadly address implications for educational practice, policy, and future research directions. / Dissertation/Thesis / Doctoral Dissertation Educational Leadership and Policy Studies 2018

Lithium Ion Batteries (LIBs) are important in today's society, powering cars and mobile devices. LIBs consist of a negative anode commonly made of graphite, and a positive cathode commonly made from transition metal oxides. Between these electrodes are separators and organic solvent based electrolyte. Due to the high potential of LIBs the electrolyte is reduced at the anode. The electrolyte reduction results in the formation of a layer called the Solid Electrolyte Interphase (SEI), which prohibits the further breakdown of the electrolyte. Despite being researched for over50 years, the composition formation of the SEI is still poorly understood. The aim of this project is to develop strategies for efficient identification and classification of various active and intermediate components in the SEI, to, in turn, gain an understanding of the reactions taking place, which will help find routes to stabilize and tailor the composition of the SEI layer for long-term stability and optimal battery performance. For a model gold/li-ion battery electrolyte system, Raman spectra will be obtained using Surface Enhanced Raman Spectroscopy (SERS) in a spectroelectrochemical application where the voltage of the working gold electrode is swept from high to low potentials. Spectra of common components of the SEI as well as similar compounds will be simulated using Density Functional Theory (DFT). The DFT data is also used to calculate the spontaneity of reactions speculated to form the SEI. The simulated data will be validated by comparing it to experimental spectra from pure substances. The spectroelectrochemical SERS results show a clear formation of Li-carbonate at the SERS substrate, as well as the decomposition of the electrolyte into other species, according to the simulated data. It is however shown that there are several issues when modelling spectra, that makes it harder to correlate the simulated spectra with the spectroelectrochemical spectra. These issues include limited knowledge of the structure of the compounds thought to form on the anode surface, and incorrect choices in simulational parameters. To solve these issues, more work is needed in these areas, and the spectroelectrochemical methods used in this thesis needs to be combined with other experimental methods to narrow down the amount of compounds to be modelled. More work is also needed to avoid impurities in the electrolyte. Impurities leads to a thick inorganic layer which prohibits the observation of species in the organic layer.

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En enkel melodi spelad på en ensam fiol är allt som behövs för att öppna ett uiversum av funderingar, tankar och känslor. Det konstnärliga examensarbetet ”Komplext, enkelt och ensamt” är en undersökning kring likheterna mellan språk och musik. Målet är att få musiken att tala och att hitta min ärligaste tolkning av Allemandan ur Bachs andra solopartita för violin. Genom att analysera satsen som om det vore poesi, med hjälp av den grekiska metrikens versfötter, har jag hittat nya rytmiska mönster i musiken som ger en djupare förståelse av styckets form och struktur. Undersökningen har gjort en genuinare tolkning möjlig. Den har också hjälp mig att tala med musik.