In today’s fast adjustment to renewable energy, new battery technologies are needed to meetthe ever-growing demands of energy storage. Cheaper and easier to produce materials areneeded, as well as materials with a lower environmental impact. One new and interestingtechnology is the dual-ion battery, and more specifically the aluminum dual-ion battery. Thisbattery uses cheap and abundant aluminum together with a graphitic cathode to work. However,a lot of research today uses expensive and sophisticated cathode materials to make this type ofbattery work. Therefore, this thesis focuses on creating a cheap and easy to produce graphitecathode material through the phase inversion method for the use in aluminum dual-ionbatteries, that is also freestanding for better energy density. Graphene is also used as anadditive to improve the electrical conductivity of the material, and the material is later tested in afull cell with the typical ionc liquid electrolyte EMImCL/AlCl4.Through phase inversion, a freestanding graphite cathode is produced with 8 wt% PVDF binderand 0.4 wt% graphene. The material has a porous structure and an enhanced electricalconductivity with the graphene added. Through CV cycling and symmetric Al-Al tests the batteryreactions are shown to work. However, when cycling the cell with a constant current there areproblems, probably coming from some sort of soft shorting or side reactions. It is revealed thatapart from the expected reactions, Ni dissolution from the contact tabs also takes place, andmay cause problems. Further tests are needed to validate if this material works. However,because no new active materials have been introduced to the battery chemistry, it is reasonableto believe that the battery will work with some small changes.Tek nisk-naturvetensk apliga fak ulteten, Upps ala universitet. Utgiv nings ort U pps al a/Vis by . H andledare: Anwar Ahniy az , Äm nesgranskar e: D aniel Brandell, Ex aminator: Lena Klintberg

Water pollution is a profound ecological concern, exerting detrimental effects on human well-being, ecological systems, and animal life. Among the emerging contaminants that critically influence water quality and have garnered substantial scientific interest in recent times are per- and polyfluoroalkyl substances (PFAS). It is crucial to investigate the de- velopment of an easy technique for PFAS detection and measurement that can be used for quick analysis. This thesis explores the possibility to use amine-functionalized mesoporous carbon as an adsorbent to develop a detection method based on sequential adsorption of per- and polyfluoroalkyl substances (PFAS) and a dye, Rose Bengal, onto the adsorbent. The hypothesis is that the concentration of non-adsorbed dye is dependent on the amount of PFAS present, making the color intensity of the remaining solution proportional to the PFAS concentration. Mesoporous carbon was chosen as the adsorbent due to their high specific surface area, providing a high adsorption capacity, and the potential to functionalize the surface with amine groups which will attract the PFAS. Rose Bengal was selected as a concentration indicator as it has been shown that it can be used as a proxy for PFAS. In this study, the most prevalent PFAS compounds, namely PFOA and PFOS, were investigated. Prior to testing, the adsorbent underwent characterization using diverse techniques to show the porosity and particle morphology. The adsorption experiments encompassed varying PFAS concentrations and a range of dye solutions to determine the detection range, the powder-to-solution ratio necessary for discernible differentiation, and the adsorption or saturation time for both PFAS and dye. This thesis concludes that it was not possible to detect neither PFOA nor PFOS in the range of 0.1 pg/mL to 1 μg/mL with the setup, even though Rose Bengal adsorption could be detected down to 0.6 μg/mL. It was further observed that amine-functionalized hard templated mesoporous carbon has a higher adsorption capacity compared to the soft templated material.

Metallic films are important in various applications, such as electric devices where it can act as contacts. In electrical devices, the substrate typically consists of silicon dioxide (SiO2) which is a temperature-sensitive substrate. Therefore, plasma enhanced chemical vapor deposition (PECVD) are better suited than thermally activated chemical vapor deposition (CVD). Depositing metallic films with PECVD demands co-reactants that act as reducing agents. However, these are not well-studied and do not always have the power enough to perform the reduction reaction for metals. Recently it has been concluded that electrons can act as reducing agents in the deposition of first row transition metallic films in a PECVD process. By supplying a positive bias to the substrate, the electrons got attracted to the surface of the substrate, which facilitated metal growth. The study concluded that metal growth only occurred at conductive -and semiconductive substrates and that the substrate bias and plasma power affected the metal growth. The process is however not well understood, which causes a knowledge gap, signifying that studies of the surface chemistry are needed. Here a new modified analytical method to study the surface chemistry in the newly developed process mentioned above is presented. The analytical method consists of an electrically modified quartz crystal microbalance (QCM) with gold electrodes as a conductive substrate. This allows the electron current to run through the QCM during the measurement. By supplying a DC-voltage to the front electrode it gets readily biased (negative and positive) and by placing a capacitor in the circuit, it connects the AC-circuit (oscillator circuit) and the DC-circuit (DC-voltage bias circuit). At the same time, it blocks the DC-current from going back to the oscillator but allows the high-frequency signal to pass from the QCM. The results in this thesis concluded that the QCM can be electrically modified to allow an electron flux to the QCM while using it as a substrate when electrons are used as reducing agents. Scanning electron microscopy (SEM) of a QCM crystal revealed that a 2 µm film had been deposited while SEM coupled with energy dispersive X-ray spectroscopy (EDS) showed that the film indeed contained iron. Further analysis was made by high-resolution X-ray photoelectron spectroscopy (HR-XPS) to find the elemental composition of the film, which revealed that the thin film contained 41 at.% iron. In addition, this study investigated if the QCM could be used to study CVD processes where electrons were used as reducing agents. The results indeed revealed that it is possible to study the surface chemistry where electrons are used as reducing agents with the electrically modified QCM to gain knowledge concerning film deposition. Initial results of the QCM showed that film growth could be studied when varying the plasma power between 5 W to 15 W and the QCM bias between -40 V to +40 V. The method generated easily accessible data concerning the process where electrons are used as reducing agents, which gained insight to the method that never has been disclosed before.

The development of future electronics depends on the availability of suitable functional materials. Printed electronics, for example, relies on access to highly conductive, inexpensive and printable materials, while strong light absorption and low carrier recombination rates are demanded in photocatalysis industry. Despite all efforts to develop new materials, it still remains a challenge to have all the desirable aspects in a single material. One possible route towards novel functional materials, with improved and unprecedented physical properties, is to form composites of different selected materials. In this work, we report on hydrothermal growth and characterization of graphene/zinc oxide (GR/ZnO) nanocomposites, suited for electronics and photocatalysis application. For conductive purposes, highly Al-doped ZnO nanorods grown on graphene nanoplates (GNPs) prevent the GNPs from agglomerating and promote conductive paths between the GNPs. The effect of the ZnO nanorod morphology and GR dispersity on the nanocomposite conductivity and GR/ZnO nanorod bonding strength were investigated by conductivity measurements and optical spectroscopy. The inspected samples show that growth in high pH solutions promotes a better graphene dispersity, higher doping and enhanced bonding between the GNPs and the ZnO nanorods. Growth in low pH solutions yield samples characterized by a higher conductivity and a reduced number of surface defects. In addition, different GR/ZnO nanocomposites, decorated with plasmonic silver iodide (AgI) nanoparticles, were synthesized and analyzed for solar-driven photocatalysis. The addition of Ag/AgI generates a strong surface plasmon resonance effect involving metallic Ag0, which redshifts the optical absorption maximum into the visible light region enhancing the photocatalytic performance under solar irradiation. A wide range of characterization techniques including, electron microscopy, photoelectron spectroscopy and x-ray diffraction confirm a successful formation of photocatalysts. Our findings show that the novel proposed GR-based nanocomposites can lead to further development of efficient photocatalyst materials with applications in removal of organic pollutants, or for fabrication of large volumes of inexpensive porous conjugated GR-semiconductor composites.

As environmental awareness raises the expectations to reduce emission of modern diesel engines are growing as well. Fuel diversity and the advanced injector systems requires even more attention on an ever existing problem which is called nozzle hole fouling. Recent literature and observations at Scania indicate the phenomena is connected to fuel filter plugging caused by metal carboxyl contaminants through the formation of “soft particles”. This report begins with a literature review about the nature of agglomerates in biodiesel. Followed by the evaluation of six particle sizing equipment. This include one ensemble technique based on Brownian motion, namely dynamic light scattering. The remaining five techniques are single particle counters, including a high speed camera system, light blocking system, Nano tracking analysis and two different approaches using light microscope. To characterise the structure and chemical components of the particles SEM, EDX, FT-IR and ICP-OES were used. From the above mentioned methods optical microscopy was chosen to be the best method to evaluate the particle distribution. The main reasons for this is the ability to measure particles in the solution in the desired size range and the possibility to couple it with a Raman spectrometer, providing possibilities for future studies. Besides finding the best technique to measure the particles, a secondary result is the negation of Zinc-neodecanoate creating particles in the fuel. It opposes the assumption made in the literature about filter blocking, and it finds the need for deeper understanding of the nature of soft particles.

Recently, the production of lithium-ion batteries (LIB) has grown rapidly, highlighting the need for efficient and environmentally friendly recycling of LIB waste. In this work, the usage of so-called deep eutectic solvents (DESs) for the leaching of the LIB cathode material lithium cobaltoxide is investigated. The initial DESs investigated are mixtures of poly(ethylene glycol) (PEG200) and an organic acid: tartaric, ascorbic, citric, oxalic or succinic acid (PEG:TA (4:1), PEG:AA (8:1), PEG:CA (4:1), PEG:OA (2:1) and PEG:SA (6:1), the molar ratio in parenthesis). Thermogravimetric analysis shows that the solvents are stable up to 180-190 °C. DESs were analyzed with FTIR spectroscopy, pH was measured using a pH-meter and viscosity using a rolling-ball viscometer. The highest leaching efficiency was obtained using PEG:AA followed by PEG:OA, both having the ability to reduce Co(III). This ability was dominant over pH and viscosity influence. For the other three solvents, leaching efficiency increases in the order of decreasing pH (PEG:TA>PEG:CA>PEG:SA). More investigations of leaching as a function of time are needed to determine the impact of viscosity. PEG:CA and PEG:AA are used to study the impact of solid-to-liquid ratio. For PEG:AA the optimal S/L-ratio is 20 mg/g. For PEG:CA the optimal S/L-ratio is different for Li and Co. Three additional CA based DESs are made using ethylene glycol (EG) and choline chloride (ChCl): EG:CA, ChCl:EG:CA and ChCl:PEG:CA. Adding ChCl to EG:CA and PEG:CA increases the leaching efficiency from ca 5 and 10 to ca 30% and the color changes from pink to blue, indicating the formation of tetrachlorocobalt complexes. This reaction may produce chlorine gas, although none was detected using potassium iodide starch paper. Study of leaching as afunction of time of ChCl:EG:CA shows the reaction slows down significantly after 24 h, indicating that the reaction has reached or is near equilibrium at this point. Antisolvent crystallization of this solvent using ethanol was not succesful.

The solar cells used today have a performance rate of about 30% in theory, but most solar cells on the market only utilize about 20% of the energy provided by sunrays. A prominent reason that the performance rate is far from 100% is the large variety of energies and corresponding wavelengths in white light. Tandem solar cells utilize two different solar cells, where the light not absorbed by the top cell travels through the top cell and onto the bottom cell. This can lead to an efficiency upward of 40%.    The purpose of this thesis was to evaluate how to use the machine Bentham PVE300 optimally for measurements of transmittance, reflectance and EQE (external quantum efficiency) with the aim to calculate the IQE (Internal quantum efficiency).   To optimize the efficiency of the tandem cells, the reflectance, transmittance and EQE needed to be measured. To do this Bentham PVE300 was used. The properties of Bentham PVE300 were explored beforehand to get a better understanding of the equipment. By reading the instrument manual and simultaneously working on the instrument, methods for the measurement of EQE, reflectance and transmittance were compiled into a manual.   The results of measurements performed by Bentham PVE300 were compared to results from other equipment to determine if the measurements were viable. Agilent Cary 7000 was used to validate the measurements of reflectance and transmittance. Bentham PVE300 was ultimately determined to be reliable and in most cases more reliable than the currently used instruments.

The particle size distribution of a powder plays a crucial role in the performance of bat- teries with powder-based electrodes and requires reliable and practical analysis. The aim of this project was therefore to develop a protocol for analysis of the particle size dis- tribution and composition of powders used in the electrodes of Nilar’s batteries. The analytical methods described in the protocol permits practical applications, such as com- paring the particle size distribution and composition of pristine and reclaimed powders with the manufacturer’s data as quality control.  A literature survey was initially conducted to select appropriate analysis methods for this project. After performing several practical trials, X-ray diffraction, X-ray fluorescence, laser diffraction analysis, and scanning electron microscopy were the techniques included in the protocol. X-ray diffraction showed potential in obtaining the crystallite size of the powders, but other techniques are required to confirm the results. X-ray fluorescence analysis was found to produce fairly similar values as those given by the manufacturer. Scanning electron microscopy was used to analyse the particle size distribution with the help of an image processing software. Complementary data of the smaller particle sizes was obtained using laser diffraction analysis.

Zeolites are crystalline aluminosilicates with diverse structures and uniform porosities. They are widely used as catalysts, adsorbents and ion-exchangers in industry. Direct or post modifications optimize the performance of zeolites for different applications. In this thesis, IZM-2 and TON-type zeolites were synthesized, modified and studied. In addition, FAU-type zeolite and silicoaluminophosphate (SAPO) molecular sieves were applied as templates for the preparation of microporous carbons. In the first part of this thesis, the IZM-2 zeolite with an unknown structure was synthesized. We focused on the increasing the secondary porosity and the varied framework compositions upon post modifications. The structure determination of this IZM-2 zeolite was hindered by the small size of crystals. In the second part of this thesis, the synthesis composition was directly modified in order to increase the crystal sizes. IZM-2 crystals were enlarged by excluding the aluminium atoms from the framework. The micropores of the obtained pure-silica polymorphs were activated by ion-exchanging alkali-metal ions with protons. Typically, TON-type zeolites that are synthesized at hydrothermal conditions under stirring have needle-shaped crystals. In the third part of this thesis, snowflake-shaped aggregates were produced by using static hydrothermal conditions for the synthesis of TON-type zeolites. The effects of synthesis parameters on the growth and morphology of crystals were discussed in detail. In the last part of this thesis, microporous carbons with a structural regularity were prepared by chemical vapour deposition (CVD) of propylene using a silicoaluminophosphate (SAPO-37) template. Compared to the conventional zeolite templates, the SAPO template could be removed under mild conditions, without using hydrofluoric acid, and the generated carbons had a large specific surface area and a high fraction of ultrasmall micropores. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.</p>

This thesis aims to provide insight into the fundamental electrochemical processes taking place when cycling SnO2 in lithium-ion batteries (LIBs). Special attention was paid to the partial reversibility of the tin oxide conversion reaction and how to enhance its reversibility. Another main effort was to pinpoint which limitations play a role in tin based electrodes besides the well-known volume change effect in order to develop new strategies for their improvement. In this aspect, Li+ mass transport within the electrode particles and the large first cycle charge transfer resistance were studied. Li+ diffusion was proven to be an important issue regarding the electrochemical cycling of SnO2. It was also shown that it is the Li+ transport inside the SnO2 particles which represents the largest limitation. In addition, the overlap between the potential regions of the tin oxide conversion and the alloying reaction was investigated with photoelectron spectroscopy (PES) to better understand if and how the reactions influence each other`s reversibility. The fundamental insights described above were subsequently used to develop strategies for the improvement of the performance and the cycle life for SnO2 electrodes in LIBs. For instance, elevated temperature cycling at 60 oC was employed to alleviate the Li+ diffusion limitation effects and, thus, significantly improved capacities could be obtained. Furthermore, an ionic liquid electrolyte was tested as an alternative electrolyte to cycle at higher temperatures than 60 oC which is the thermal stability limit for the conventional LP40 electrolyte. In addition, cycled SnO2 nanoparticles were characterized with transmission electron microscopy (TEM) to determine the effects of long term high temperature cycling. Also, the effect of vinylene carbonate (VC) as an electrolyte additive on the cycling behavior of SnO2 nanoparticles was studied in an effort to improve the capacity retention. In this context, a recently introduced intermittent current interruption (ICI) technique was employed to measure and compare the development of internal cell resistances with and without VC additive.