”Coin cell”-tillverkningen täcker hela processen från NMC-pulver till faktisk cell- och prestandautvärdering genom att cykla celler. Nydanande utveckling av elektrodmaterialen är nyckeln till att öka energitätheten hos litium-jon/metall-batterier för elfordon och nätlagring. Prestandan hos nya katodmaterial utvärderas vanligtvis genom att sätta samman knappcellsbatterier (coin cell) som s.k. halvceller med katodmaterialet som arbetselektrod och litium som motelektrod. Detta dokument beskriver ingående metodvalideringen för tillverkning av knappcellsbatterier. Dokumentet innehåller metodik, resultat och slutsatser från den genomförda metodvalideringen. Syftet med denna studie var att validera en befintlig metod för tillverkning av knappceller, och förbättra metoden genom att upptäcka de största källorna till avvikelser och eliminera dem. För validering Gauge R och R görs linjäritetstest för att validera noggrannhet och precision av metoden vilket är en del av sex sigma-strategin som används i många industrier. Verifieringen görs med livscykeltest och impedansspektroskopi. Den validerade metoden kommer att implementeras som standard i kvalitetskontrollabbet vid Northvolt Labs för att testa de elektrokemiska egenskaperna och prestandan hos kalcinerat NMC-material. / Coin cell manufacturing involves the entire process from NMC powder to the actual cell and performance evaluation through cycling. The development of novel positive electrodes is the most important way to increase the energy density of lithium-ion/metal batteries for electric vehicles and grid storage. The performance of new cathode/anode materials is usually evaluated by assembling coin half cells with a working electrode as the cathode and lithium as the counter electrode. This document describes in detail the procedure used in method validation for coin cell fabrication. The document includes the validation study methodology, results, and conclusions. The objective of this study was to validate an existing method for coin cell manufacturing, to identify and eliminate the main sources of variation, and thus to improve the method. For validation, Gage R and R measurements, linearity and bias tests are performed to verify the accuracy and precision of the method, which is part of the Six Sigma strategy used by many companies. Cycle life and electrochemical impedance spectroscopy are used to verify the developed methods. The validated method will be implemented as a standard in Northvolt’s quality control laboratory to test the electrochemical properties and performance of calcined NMC material.

Use of arsenic-rich groundwater for crop irrigation can increase the arsenic (As) content in food crops and act as a carcinogen, compromising human health. Using aquatic plant based phytofiltration is a potential eco-technique for removing arsenic from water. The aquatic moss species Warnstorfia fluitans grows naturally in mining areas in northern Sweden, where high concentrations of arsenic occur in lakes and rivers. This species was selected as a model for field, climate chamber and greenhouse studies on factors governing arsenic removal and arsenic phytofiltration of irrigation water. The arsenic and silicon (Si) concentrations in soil, water and plant samples were measured by AAS (atomic absorption spectrophotometry), while arsenite and arsenate species were determined using AAS combined with high pressure liquid chromatography (HPLC) with an anion exchange column. The arsenic content in grains of hybrid and local aromatic rice (Oryza sativa) cultivars with differing arsenic accumulation factor (AF) values was investigated in an arsenic hotspot in Bangladesh. The results showed that arsenic AF was important in identifying arsenic-safer rice cultivars for growing in an arsenic hotspot. The study based on silicon effect on arsenic uptake in lettuce showed that arsenic accumulation in lettuce (Lactuca sativa) could be reduced by silicon addition. The aquatic moss had good phytofiltration capacity, with fast arsenic removal of up to 82% from a medium with low arsenic concentration (1 µM). Extraction analysis showed that inorganic arsenic species were firmly bound inside moss tissue. Absorption of arsenic was relatively higher than adsorption in the moss. Regarding effects of different abiotic factors, plants were stressed at low pH (pH 2.5) and arsenic removal rate was lower from the medium, while arsenic efflux occurred in arsenate-treated medium at low (12°C) and high (30°C) temperature regimes. Besides these factors, low oxygenation increased the efficiency of arsenic removal from the medium. Finally, combining W. fluitans as a phytofilter with a lettuce crop on a constructed wetland significantly reduced the arsenic content in edible parts (leaves) of lettuce. Thus W. fluitans has great potential for use as an arsenic phytofilter in temperate regions. / <p>QC 20170323</p>

In this thesis, a Sb/C composite electrode for sodium-ion batteries isprepared by a simple high energy ball milling and calenderingmethod. The prepared Sb/C composite electrode was assembled in ahalf-cell and symmetrical cell setups in order to perform avariety of electrochemical measurements.The composite electrode showed a reversible specific capacity of595 mAh/g, at a discharge/charge current rate of 15 mA/g. Theelectrode also showed a relatively good performance (compared toprevious studies) of 95% capacity retention after more than 100cycles, at a higher discharge/charge current rate of 60 mA/g. Theelectrode furthermore showed excellent self-dischargecharacteristics, in pause tests implemented over 200 hours (overeight days), which underlined the electrode materials good shelflife properties. A series of Sb/C symmetrical cells assembledthrough-out the project, furthermore, highlighted the stability ofthe solid electrolyte interface (SEI) layer formed on the Sb/Ccomposite electrode during cycling. Scanning electron microscopy(SEM) and Energy-dispersive X-ray spectroscopy (EDS) were used tocharacterize the surface morphology and composition of the Sb/Celectrode, respectively.A non-milled and milled (12 hours) graphite electrodes were alsoprepared for reference and comparison. The milled graphite matrixelectrode provided a reversible capacity of 95 mAhg-1 and acoulombic efficiency (CE) of 99% in over 250 cycles, at a currentrate of 30 mA/g. Milled and non-milled graphite were characterizedwith SEM and Raman spectroscopy, to help have a fundamentalunderstanding of the particle size and material phase,respectively.

During the past decades, emission of greenhouse gases has accelerated to unsustainable levels. This is a serious issue that can have a devastating impact on everything from global economy to the terrestrial or marine ecosystem. A method for reducing the emission is named carbon capture and storage, which this project is based on. In this study, different concentrations of citric acid (CA) is used (as an additive) for the enhancement and optimization of carbon dioxid sorption properties of amorphous calcium carbonate (ACC), mesoporous magnesium carbonate (MMC) and calcium magnesium carbonate composite (CMC). These materials were heat treated in a calcination and an alternating carbonation process in order to study the carbon dioxid sorption performance. During the calcination process, CA undergoes a pyrolysis reaction in order to increase the specific surface area of the individual nanoparticles, which is an important factor for the sorption capacity. In the case of CMC, different molar ratios of magnesium oxide and calcium oxide were used in order to alter the concentration of the resulting magnesium oxide prior to heating. All three materials consisted of aggregations of nanometer-sized particles. Thermogravimetric analysis, scanning electron microscopy, surface area and porosimetry and infrared spectroscopy analysis suggest that the carbon dioxid sorption properties and the sintering stability of ACC and MMC do not improve since CA evaporates due to pyrolysis. Sintering was a greater problem for the evaluated CA treated ACC sample. However, in the case of CMC, the sorption and sintering properties were enhanced due to the higher Tamman-temperature of magnesium oxide, specifically for the lower concentration of magnesium oxide. After 19 carbonation cycles, CMC-1:1-25% CA showed signs of improved sintering stability and sorption capacity, compared to ACC-75% CA. / <p>Presentationen genomfördes på distans.</p>

Förbrukat kärnbränsle är mycket radioaktivt och behöver därför lagras i djupa geologiska förvar i tusentals år innan det säkert kan återföras till naturen. På grund av de långa lagringsperioderna görs säkerhetsanalyser av de djupa geologiska förvaren. Under säkerthetsanalyserna görs upplösningsexperiment på förbrukat kärnsbränsle för att utvärdera konsekvenserna av att grundvatten läcker in i bränslet vid barriärbrott. Dessa experiment är både dyra och tidskrävande, varför beräkningsmodeller som kan förutsäga förburkat kärnbränsles upplösningsbeteende är önskvärda. Denna avhandling fokuserar på att samla in tillgängliga experimentella data från upplösningsexperiment för att uppdatera och utöka en databas. Med hjälp av databasen har upplösningsbeteendet för varje radionuklid utvärderats och jämförts med tidigare kunskap från befintlig litteratur. Även om det var svårt att vara avgörande om beteendet hos element där en begränsad mängd data fanns tillgänglig, motsvarar de upplösningsbeteenden som hittats för olika radionuklider i denna avhandling inte bara tidigare studier utan ger också ett verktyg för att hantera och jämföra förbrukat kärnbränsles upplösningsdata från olika utgångsmaterial, bestrålningshistorik och betingeleser under upplösning. Dessutom gjorde sammanställningen av en så stor mängd experimentella data det möjligt att förstå var framtida experimentella ansträngningar bör fokuseras, exempelvis finns det en brist på data under reducerande förhållanden. Dessutom utvecklades och kördes maskininlärningsmodeller med hjälp av Artificial Neural Network (ANN), Random Forest (RF) och XGBoost-algoritmer med hjälp av databasen, varefter prestandan utvärderades. Prestanda för varje algoritm jämfördes för att få en förståelse för vilken modell som presterade bäst, men också för att förstå om dessa typer av modeller är lämpliga verktyg för att förutspå förbrukat kärnbränsles upplösningsbeteende. Den bäst presterande modellen, med träning och test R2 resultat nära 1, var XGBoost-modellen. Även om XGBoost hade en hög prestanda, drogs slutsatsen att mer experimentell data behövs innan maskininlärningsmodeller kan användas i verkliga situationer. / Spent nuclear fuel (SNF) is highly radioactive and therefore needs to be stored in deep geological repositories for thousands of years before it can be safely returned to nature. Due to the long storage times, performance assessments (PA) of the deep geological repositories are made. During PA dissolution experiments of SNF are made to evaluate the consequences of groundwater leaking into the fuel canister in case of barrier failure. These experiments are both expensive and time consuming, which is why computational models that can predict SNF dissolution behaviour are desirable.  This thesis focuses on gathering available experimental data of dissolution experiments to update and expand a database. Using the database, the dissolution behaviour of each radionuclide (RN) has been evaluated and compared to previous knowledge from existing literature. While it was difficult to be conclusive on the behaviour of elements where a limited amount of data was available, the dissolution behaviours found of different radionuclides in this thesis not only correspond to previous studies but also provide a tool to manage and compare SNF leaching data from different starting materials, irradiation history and leaching conditions. Moreover, the compilation of such a large amount of experimental data made it possible to understand where future experimental efforts should be focused, i.e. there is a lack of data during reducing conditions. In addition, machine learning models using Artificial Neural Network (ANN), Random Forest (RF) and XGBoost algorithms were developed and run using the database after which the performances were evaluated. The performances of each algorithm were compared to get an understanding of which model performed best, but also to understand whether these kinds of models are suitable tools for SNF dissolution behaviour predictions. The best performing model, with training and test R2 scores close to 1, was the XGBoost model. Although XGBoost, had a high performance, it was concluded that more experimental data is needed before machine learning models can be used in real situations.

’Netto-noll utsläpp’ i EU vid 2050 är ett av målen för att påskynda övergången från fossila bränslen till mer förnyelsebara och hållbara alternativ. Detta har däremot introducerat mer turbulens på elnäten. Ett av verktygen för att reglera och förbättra eldistributionen är stor-skaliga batterier, där litium-jon är den mest förekommande kemin. Men på grund av oro kring resursutbud och hopp om teknologidiversifiering har det påbörjat en sökning efter alternativ som kan användas i stället eller tillsammans med litium-jon batterier. Från en lång lista så har tre alternativ med hög potential identifierats. Dessa är nickel-vätgasbatteri, zink-brom flödesbatteri och järn-luftbatteri. Deras lämplighet undersöktes och diskuterades för flertalet användningsområden och för ett speciellt användarfall av Vattenfall. Slutsatsen var att utav de tre, så är det endast nickel-vätgas som kan förväntas vara ett bra alternativ för specifika fall, att zink-brom har få möjligheter att konkurrera och att järn-luft har väldigt hög potential men också många oklarheter som gör det svårt att förutspå dess utveckling. / With net-zero emissions set to be achieved in the EU by 2050, the transition from fossil-based energy sources to more renewable and green options are ever expanding. This puts a strain on the electricity grids because of the intermittent nature from these energy sources. To mitigate this battery systems are used, of which the lithium-ion battery is the most prevalent, and expected to only increase in use. However, material resource concerns and possible danger of over-reliance on one technology has opened for a search to find other alternatives that could be used instead or in conjunction with the battery. Out of a long list of batteries, the nickel-hydrogen battery, zinc-bromide flow battery and iron-air battery are three alternatives that have been identified to have potential. Their suitability was researched and discussed for various grid-applications. The result show that out of the three, it is only believed that the nickel-hydrogen battery have a definitive competitiveness, that the zinc bromide flow battery has few things going for it, and that the iron-air battery has large potential but just as large uncertainty surrounding its future. Lastly, a specific off-shore wind park case was investigated to see the practicality and competitiveness of the nickel-hydrogen battery compared to a specific lithium-ion chemistry.

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 beskrivaåldringsprocessen 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 elektrokemiskaåldringsmekanismer 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.

The demand for today's material resources for energy storage is rapidly increasing and can result in both environmental and political conflicts that can affect the development of electronic devices due to high prices and limitations of raw materials for batteries. In this study, potential future composite electrodes were synthesised with an ex-situ approach by compositing redox-active 2,6-Diaminoanthraquinone and 1,3,5-Triformylphloroglucinol covalent organic framework (DAAQ-TFP COF) with conductive delaminated Ti3C2Tx MXene to maximise the number of redox-active moieties during cycling. In addition, solvothermal synthesis with the implementation of mechanical grinding as an exfoliation method was used to try to obtain DAAQ-TFP nanosheets to increase both the contact area between the two materials and the number of charge carriers. The sample was analysed with PXRD and BET surface analysis to characterise the crystallinity meanwhile SEM was utilised to study the morphology of the COF and the composite material. The specific capacitance of each electrode was estimated by cyclic voltammetry. The study showed a decrease in reduced specific capacitance with lower MXene content. Hence, this concludes pure Ti3C2Tx sheets have the highest capacitance contribution with a value of 48.79 Fg-1 meanwhile the composite electrode with a ratio of 1:1 was estimated to 32.26 Fg-1 with 0.0928 % of its moieties undergoing a redox reaction. A reduced capacitance with an increased COF-MXene ratio indicates that MXene contributes with more capacity relative to the COF, in combination with a non-successful exfoliation of DAAQ-TFP to single-layered nanosheets, reducing the interactions between the two materials.

Energiförbrukning är ett hett ämne i världen idag, eftersom världens befolkning fortsätter att växa. Som ett resultat ökar också den globala energiförbrukningen snabbt och utsläppen av koldioxid därmed, vilket påverkar global uppvärmning och klimatförändringar. Således kommer utvecklingen av förnybara energikällor att bli en av nödvändighet. Solenergi utgör en förnybar energikälla och uppvisar en enorm potential för att tillgodose det globala energibehovet. En solcell är kan användas för att omvandla solljus till elektricitet. Många typer av solceller har utvecklats under det senaste decenniet, och forskning för att förbättra effektiviteten kommer att fortsätta i framtiden. Material baserade på kopparhalogenidkomplex har uppvisat intressanta optiska och elektrokemiska egenskaper på grund av flera laddningsöverföringsexciterade tillstånd. Genom att kombinera kopparhalogenidsystem med organiska ligander med två bindningsgrupper, kommer komplexet att kunna bilda nätverksstrukturer i flera dimensioner och därmed effektivt kunna leda ström. Eftersom kopparhalogenidkomplex uppvisar unika optiska och elektriska egenskaper, är det värt att undersöka dem för användning i solceller. Syftet med examensarbete har varit att undersöka kopparhalogenidkomplex med optiska och elektrokemiska egenskaper. Kopparhalogenidkomplex med bidentatligander har syntetiserats och applicera som tunna filmer undersöktes. I kapitel 1 och 2 av uppsatsen presenteras bakgrunden och en introduktion av denna studie, samt de experimentella metoderna. I kapitel 3 beskrivs syntesen av kopparjodid-4,4'-bipyridinkomplex och karakteriseringen av detsamma. Applicering av det resulterande materialet på glassubstrat diskuteras också. I kapitel 4 beskrivs syntesen av kopparhalogenid-N-oxid-4,4'-bipyridinkomplex med efterföljande karakterisering. I kapitel 5 undersöks metoder för att applicera kopparjodidpyridin på koppar-folie och FTO-belagda glassubstrat. / Energy consumption is presently a hot topic in the world since the world’s population continues to grow. As a result, global energy consumption is increasing rapidly and the emission of carbon dioxide is also increasing, which causes global warming and climate change. Thus, the development of renewable energy sources will be one of the solutions. Solar energy is one of the renewable energy sources and has a huge potential to satisfy the global energy demand. A solar cell harvests light and converts it to electricity. Many kinds of solar cells have been developed in the past decades, and investigation for the improvement of the efficiency will be continued in the future. Copper halide organic complex materials have some potential for optical and electrochemical properties due to several charge transfer states inside the structure. By combining copper halide with bidentate organic ligands, the complex will form high dimensional network structure and will have electrical property due to the formation of electron conducting paths. Since copper halide complex has potential for unique optical and electrical properties, it is worth investigating for the further photovoltaic application. The aim of the thesis is to investigate copper halide complex material showing optical and electrochemical property. Copper halide complex with bidentate ligands were synthesized and the way to apply copper halide complex to films were also investigated in this thesis. In chapter 1 and 2, the background and the introduction of this study and the experimental methods are presented. In chapter 3, the synthesis of copper iodide 4,4’-bipyridine complex and the characterization of the complex sample are presented. The application of the complex to glass substrate is also discussed. In chapter 4, the synthesis of copper halide N-oxide-4,4’-bipyridine complex and the characterization are discussed. In chapter 5, the way to apply copper iodide pyridine to copper foil and FTO-coated glass substrate is discussed.

The United Nations have set a number of sustainability goals, Agenda 2030, in order to combat the worlds largest challenges and injustices. The energy market is one of these urgent issues which must be solved. Solar energy is expected to be the fastest growing energy source in the future energy mix. It can be a great way to provide zero emission energy and also become a key part in equality as it can provide energy to people who live off the grid today and raise quality of life all over the world. The aim of this study is to compare different ligands in a copper halide complex to conclude what structural properties of the ligand might be better suited for photoluminescent applications, and especially in solar cells. Eight ligands were chosen for the complexes depending on their level of conjugation: 4,4’-bipyridine, tri(o-tolyl)phosphine, 3,6-di-2-pyridyl-1,2,4,5-tetrazine, pyridine, pyrimidine, pyrazine, phenanthroline, and 2,2’-bipyridine. A series of analytical methods were used to compare the complexes properties; X-Ray diffraction, emission and excitation spectroscopy, time-resolved photoluminescence spectroscopy, microscopy and thermochromism. From these measurements, pyridine and pyrimidine proved to have the greatest potential for working in a solar cell. This was deduced because of the detected crystallinity, having luminescence under UV-light, forming distinct wavelength peaks during excitation and emission in the flourometer, having the longest excited state lifetime and and finally, emitting distinctive colours during thermochromism. When creating the solar cell, pyridine was chosen as ligand due to higher availability than pyrimidine. The method used in this project for making the solar cell is directly applied form a previously tested method, but which was designed for another type of electron donor. This project compared the different ways of applying the copper halide complex on to the cell. The methods used were spin-coating and SILAR for creating the copper iodide thin film and vapour diffusion and immersion to introduce the ligand. These four methods were combined systematically for all combinations. The solar cells were then put in a solar simulator where voltage, current, efficiency and fill factor was measured. The best results came form the solar cell where spin coating and immersion was used, though the overall efficiency of the created cells were low. Copper halide complexes in previous studies have been proven to be reactive with oxygen and the experiments in this project were not carried out in an inert environment. This could have had significant impact on the measurements, as reactions between the complexes and oxygen may have resulted in oxidation and thus inactivation of the complexes. Therefore, it would be interesting to conduct the syntheses again but instead in an inert environment to determine whether oxygen made a major impact on the measurements. In further studies, it would also be worthwhile to investigate how the different layers of the solar cell would have to be adapted for this particular complex to obtain higher efficiency and voltage. Also, making thin film of pyrimidine to be used in a solar cell as it showed the attributes required for a solar cell. Furthermore, it would be interesting to use derivatives of pyrimidine, such as uracil and cytosine which are abundant in nature, as they might be more sustainable choices. This is due to their inherent biodegradability and not posing a threat to either health or environment when handled.