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Albertan coal has been used to produce extracts as precursor for production of anode coke. Coal extractability was studied using digestion with Tetralin in a 500 ml reactor. Different operating conditions were tried and optimum conditions were chosen for runs with coal-derived solvents. Extracts from runs with coal-derived solvents and their hydrotreated versions were distilled and heat treated to produce pitches as coke precursors. Coking experiments were performed using a molten salt bath furnace. Coal, solvents, pitches and cokes were characterized to study the effects of process chemistry on coke anisotropy. Coke anisotropy was studied using image analysis of polarized light optical micrographs and x-ray diffraction. Aromaticity of the pitch was found to be the key parameter controlling coke anisotropy. Solvent was found to be the most important factor contributing to pitch aromaticity. Heat treated products of high aromaticity yield the highest coke conversion and anisotropy. / Chemical Engineering

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<div>Potassium-ion batteries (PIBs) recently emerged as a next-generation energy storage technology, utilizing abundant and inexpensive potassium as the charge carrier cation. PIBs operate by an analogous mechanism to lithium-ion batteries (LIBs), with reversible potassium intercalation in anode and cathode through an inorganic salt - organic solvent electrolyte medium. Despite its larger size, potassium exhibits several electrochemical advantages over sodium, including a higher affinity for intercalation into graphitic (carbonaceous) anodes, forming a stage-one KC₈ structure in graphite for a specific capacity of 279 mAh g^-1. This thesis aims to provide a thorough foundation for PIB carbon anodes, through a comprehensive experimental approach combining electrode synthesis, advanced material characterization and electrochemical-analytical techniques.</div><div><br></div><div>Safety concerns have consistently plagued LIBs despite almost three decades of widespread commercialization. Thermal runaway of LIBs can initiate as early as 80°C from exothermic breakdown of the solid electrolyte interphase (SEI) layer that covers the carbon anode surface. The subsequent reaction of lithiated carbon with electrolyte solvent leads to cathode decomposition and oxygen release for cell gassing and combustion. This thesis investigates the thermal runaway behavior of graphite anode for PIBs via differential scanning calorimetry analysis, determining the effect of electrode material, state-of-charge, and cycling history on heat generation. Notably, the PIB system emits significantly less heat overall than for LIBs, albeit an earlier and more intense onset reaction at 100°C raises safety concerns. Strategies to mitigate this exothermic reaction are presented, including electrode binder manipulation to improve graphite particle coverage and enhance SEI layer stability.</div><div><br></div><div>To further evaluate the practicality of PIBs, the electrochemical behavior of graphite anode was investigated from 0 - 40°C operating temperature, in comparison to standard LIBs. The poor rate capability of potassium is attributed to sluggish solid-state diffusion and augmented cell impedance, where 3-electrode studies revealed dramatic polarization of the potassium metal counter electrode at low temperatures. Accelerated cell aging at elevated temperatures is attributed to SEI layer growth induced by the 61% volumetric expansion of graphite during potassiation, as well as the extreme reactivity of potassium metal. A full-cell system with a Prussian blue nanoparticle cathode and graphite anode showed enhanced rate performance at low temperatures by removing potassium metal counter electrode. These results provide valuable mechanistic insight for potassium intercalation in graphite and offer a practical evaluation of temperature dependent electrochemical performance for PIBs.</div><div><br></div><div>Supplementary research includes the exploration of carbon nanofibers electrospun from polyacrylonitrile precursor with subsequent pyrolysis as PIB anode. The design of an amorphous, low density carbon with a nanoscale one dimensional morphology enables mitigation of the 61% volumetric expansion of graphite during potassiation. Remarkable stability (2000 charge-discharge cycles) is thus achieved by preventing electrode pulverization, SEI layer growth, and impedance rise during cycling. Electrochemical analysis revealed a pseudo-capacitance mechanism, enabling rapid charging through surface storage of potassium that could be enhanced by surface functionalization via plasma oxidation treatment. Moreover, two dimensional MXene transition carbonitride sheets were explored as PIB anode with X-ray diffraction and X-ray photoelectron spectroscopy used to study structural changes during potassium insertion.</div><div><br></div><div>Finally, the effect of particle morphology was investigated for LIB carbon anodes, wherein commercial graphite is compared with synthesized spherical and spiky carbons. Intercalation dynamics, side reaction rates (e.g. SEI growth), self-heating, and thermal runaway behavior were studied through a combination of electrochemical analysis and modeling by a finite volume method. Spherical particles outperform irregular commercial graphite by eliminating unstructured inhomogeneities that lead to non-uniform current distributions. Interestingly, spiky particles offer a nontrivial response, where the ordered irregularities enhance intercalation dynamics to prevent degradation at extreme operating conditions. These findings emphasize the importance of tailoring particle morphology and structure in promoting desired LIB behavior and suppressing unwanted problems.</div>

Den högkvalitativa stenkolstjäran, som används som anodbindemedel inom aluminiumindustrin, innebär utmaningar när det gäller att möta kraven på kolanod. Dess produktion är beroende av ohållbara fossila bränslen, vilket bidrar till ökade koldioxidutsläpp. Följaktligen är det ett iögonfallande forskningsämne att finna ett hållbart alternativ. Produkten av biooljauppgradering, så kallat biobeck, kan anses vara en genomförbar utmanare. Detta biobeck undersöks som ett potentiellt substitut för stenkolstjärabeck på grund av dess liknande reologiska egenskaper. Det primära syftet med denna studie är att utsätta tre biooljor från samma källa för olika värmebehandlingsmetoder och screena en riktig bioolja för vidare arbete. Karakteriseringen av dessa biooljor och deras destillationsprodukter syftar till att öka deras lämplighet som potentiella substitut för stenkolstjärabeck. Olika destillationsförhållanden ger olika resultat från de tre biooljorna. Fysiska och kemiska egenskapstester utförs på både bioolja och biobeck, såsom vattenhalt, FTIR, TGA och viskositet. Genom att jämföra dessa värden med karakteriserade koltjärabeckdata från litteraturen kan lämpliga biooljekandidater identifieras, och distinktionerna mellan biobeck och stenkolstjärabeck kan undersökas. Denna utforskning ger förståelse för att tillhandahålla justeringar i destillationsprocessen. / The high-quality coal-tar-pitch, used as an anode binder within the aluminum industry, poses challenges in meeting requirements of carbon anode. Its production relies on unsustainable fossil fuels, contributing to heightened carbon dioxide emissions. Consequently, It is an eye-catching research topic to distinguish a sustainable alternative. The product of upgrading bio-oil, named bio-pitch, can be considered a doable contender. This bio-pitch is being explored as a potential substitute for coal-tar pitch because of its similar rheological properties. The primary objective of this study is to subject three bio-oils from the same source to distinct heat treatment methods and screen a proper bio-oil for further work. The characterization of these bio-oils and their distilling products aims to raise their suitability as potential substitutes for coal-tar-pitch. Different distillation conditions yield varied bio-pitch outcomes from the three bio-oils. Physical and chemical property tests are conducted on both the bio-oil and bio-pitch, such as water content, FTIR, TGA, and viscosity. By comparing these values to characterized coal-tar-pitch data from the literature, suitable bio-oil candidates can be identified, and the distinctions between bio-pitch and coal-tar-pitch can be investigated. This exploration provides understanding to furnish adjustments in the distillation process.