Recent advances in the electric & hybrid electric vehicles and rapid developments in the electronic devices have increased the demand for high power and high energy density lithium ion batteries. Graphite (theoretical specific capacity: 372 mAh/g) used in commercial anodes cannot meet these demands. Amorphous SnO2 anodes (theoretical specific capacity: 781 mAh/g) have been proposed as alternative anode materials. But these materials have poor conductivity, undergo a large volume change during charging and discharging, large irreversible capacity loss leading to poor cycle performances. To solve the issues related to SnO2 anodes, we propose to synthesize porous SnO2 composites using electrostatic spray deposition technique. First, porous SnO2/CNT composites were fabricated and the effects of the deposition temperature (200,250, 300 oC) & CNT content (10, 20, 30, 40 wt %) on the electrochemical performance of the anodes were studied. Compared to pure SnO2 and pure CNT, the composite materials as anodes showed better discharge capacity and cyclability. 30 wt% CNT content and 250 oC deposition temperature were found to be the optimal conditions with regard to energy capacity whereas the sample with 20% CNT deposited at 250 oC exhibited good capacity retention. This can be ascribed to the porous nature of the anodes and the improvement in the conductivity by the addition of CNT. Electrochemical impedance spectroscopy studies were carried out to study in detail the change in the surface film resistance with cycling. By fitting EIS data to an equivalent circuit model, the values of the circuit components, which represent surface film resistance, were obtained. The higher the CNT content in the composite, lower the change in surface film resistance at certain voltage upon cycling. The surface resistance increased with the depth of discharge and decreased slightly at fully lithiated state. Graphene was also added to improve the performance of pure SnO2 anodes. The composites heated at 280 oC showed better energy capacity and energy density. The specific capacities of as deposited and post heat-treated samples were 534 and 737 mAh/g after 70 cycles. At the 70th cycle, the energy density of the composites at 195 °C and 280 °C were 1240 and 1760 Wh/kg, respectively, which are much higher than the commercially used graphite electrodes (37.2-74.4 Wh/kg). Both SnO2/CNTand SnO2/grapheme based composites with improved energy densities and capacities than pure SnO2 can make a significant impact on the development of new batteries for electric vehicles and portable electronics applications.

Li-ion batteries have become one of the chosen energy storage devices that are used in applications such as power tools, cellular phones and electric vehicles (EV). With the demand for portable high energy density devices, the rechargeable Li-ion battery has become one of the more viable energy storage systems for large scale commercial EVs because of their higher energy density to weight or volume ratio when compared to other current commercial battery energy storage systems. Various safety procedures for the use of Li-ion batteries in both consumer and EV applications have been developed by the international associations. The test procedures studied in this dissertation demonstrated the importance of determining the true capacity of a cell at various discharge rates. For this, the well known Peukert test was demonstrated. The study also showed that cells with different battery geometries and chemistries would demonstrate different thermal heating during discharge and slightly different Ragone results if different test methods were used as reported in the literature. Accelerated ageing tests were done on different cells at different Depth-of-Discharge (DoD) regions. The different DoD regions were determined according to expected stresses the electrode material in a cell would experience when discharged to specific DoD that follows the discharge voltage profile. Electrochemical Impedance Spectroscopy (EIS) was used to measure various electrochemical changes within these cells. The EIS results showed that certain observed modelled parameters would change similarly to the ageing of the cell as it aged due to the accelerated testing. EIS was also done on cells at different State-of-Charge (SoC) and temperatures. The results showed that EIS can be used as an effective technique to observe changes within a Li-ion cell as the SoC or temperature changed. For automotive vehicles that are powered by a fuel cell or battery, a supercapacitor can be coupled to a battery in order to increase and optimize the energy and power densities of the drive systems. A test procedure in the literature that evaluated the use of capacitors with Pb-acid batteries was applied to Li-ion type cells in order to quantify the increased power due to the use of a supercapacitor with a Li-ion cell. Both a cylindrical LiCoO2 cell and a VRLA Pb-acid cell showed some additional charge acceptance and delivery when connected to the supercapacitors. A LiMn2O4 pouch cell showed significant charge acceptance and delivery when connected to supercapacitors. The amount of additional charge acceptance and delivery of the different combinations could be explained by EIS, in particular, the resistance and capacitance of the cell in comparison to the combination of the cell and supercapacitor. A large capacity LiCoO2 cell showed high charge acceptance and delivery without connection with a supercapacitor. The study proved that EIS can be used to model the changes within cells under the different conditions and using different test procedures.

The aim of this thesis is to examine the effect that Thermal Energy Storage (TES) sizing has on a building’s ability to meet heating and cooling demands in an energy and cost efficient manner. The focus of the research is the quantification the effects of TES for system sizing and boiler cycling. Research is accomplished by modelling TES systems with various storage capacities using thermodynamic analysis. Energy costs are subject to increase during peak usage periods due to a limited supply of energy. Peak heating and cooling periods also force thermal systems to be sized for loads that are only experienced for a small fraction of the year leading to poor efficiencies and frequent cycling during off peak times of year. TES introduces the capability to mitigate this issue by shifting peak thermal loads from one period to another, theoretically reducing the minimum necessary boiler or chiller capacity for a given system and potentially improving the efficiency of 4 thermal systems. The scope of this research is to model the operation of thermal systems with varying storage capacities in order to quantify these capabilities with respect to capacity and cycling. This is accomplished with modelling in Transient Systems Simulation Program (TRNSYS). In this software, a simple heating loop and cooling loop are independently considered and subjected to hourly load data extrapolated from heating and cooling load data originating from a retirement community in Massachusetts. The model built is intended to be robust enough to be easily applied and adapted to assess similar problems with energy storage capacity sizing.

Sala-Heby Energi Elnät is a supplier of electrical power for the communities of Sala, Heby, Morgongåva and Björnarbo in Uppland, Sweden. The electrical power grid in this area is currently facing several challenges. Bottlenecks and power shortages are some of them. As an expansion of the Swedish power grid lies many years in the future, there is a need for other solutions to these problems. Because of this, Sala-Heby Energi Elnät is looking at the prospect of installing an energy storage system in the small community of Björnarbo. This report investigates a number of the most commonly used energy storage options available today and concludes that the most suitable choice for Sala-Heby Energi Elnät would be lithium-ion batteries implemented in a battery energy storage system, a BESS. This report also focuses on how a BESS can reduce power peaks by using a method called peak shaving. The financial implications of implementing a BESS of this kind for this purpose are taken into account as well. The study shows that by utilising a BESS with an energy capacity of 500kWh, the power peaks can be reduced by peak shaving. This not only provides a solution to the capacity problem in Sala-Heby Energi Elnät’s power grid, but a BESS could also allow for them to reduce their power subscription to Vattenfall, Sweden’s electricity provider. This would allow Sala-Heby Energi Elnät to make some financial savings. However, a BESS of this type would be very expensive. The conclusion is that a BESS could manage the energy consumption by using peak shaving but will only be financially profitable in the long run for Sala-Heby Energi Elnät.

Energy use around the world will rise in the coming decades. Renewable energy sources will help meet this demand, but renewable sources suffer from intermittency, uncontrollable power supply, geographic limitations, and other issues. Many of these issues can be mitigated by introducing energy storage technologies. These technologies facilitate load following and can effectively time-shift power. This analysis compares dedicated and synergistic energy storage technologies using energy efficiency as the primary metric. Energy storage will help renewable sources come to the grid, but fossil fuels still dominate energy sources for decades to come in nearly all projections. Carbon capture technologies can significantly reduce the negative environmental impact of these power plants. There are many carbon capture technologies under development. This analysis considers both the innovative and relatively new cryogenic carbon capture™ (CCC) process and more traditional solvent-based systems. The CCC process requires less energy than other leading technologies while simultaneously providing a means of energy storage for the power plant. This analysis shows CCC is effective as a means to capture CO2 from coal-fired power plants, natural-gas-fired power plants, and syngas production plants. Statistical analysis includes two carbon capture technologies and illustrates how uncertainty quantification (UQ) provides error bars for simulations. UQ provides information on data gaps, uncertainties for property models, and distributions for model predictions. In addition, UQ results provide a discrepancy function that can be introduced into the model to provide a better fit to data and better accuracy overall.

Energy storage is of increasing interest as an enabler of incorporating renewable intermittent power in the power systems globally. There are several technologies for energy storage, and this thesis focuses on battery energy storage systems (BESS). Previous research has shown that it is difficult to install BESS with a payback time within the battery lifetime, making it a challenge to realise profitable investments. The complexity of developing an optimal control of the battery is also documented in research as another challenge. Optimal sizing of the BESS could be a solution to the challenge of reaching profitability. The thesis is identifying and analysing some important technical and energy-related parameters affecting the performance of BESS installations. Identification and analysis of parameters affecting the performance will help build insight into the optimization of BESS and help enable the development of more efficient sizing and operation. By developing an algorithm simulating the BESS when controlled using two different strategies, this thesis additionally contributes to the research by displaying the complexity of battery control, which is realised by the energy management system (EMS). Thereby the thesis is adding to the research base for the future development of smarter and more optimal EMS. The main research methodologies used in the thesis was a literature study and a case study. The results suggested that the energy management strategy used in the battery control was gravely affecting the performance in terms of economic profitability, self-sufficiency and environmental impact. It was also implied that it is difficult to develop an efficient battery control to reach the full potential of the storage system. The main conclusions in this paper are that the most important parameters to consider when implementing a battery storage in a residential multifamily building are battery technology, battery capacity, building load, renewable energy generation, energy management strategy as well as the electricity prices and investment cost. The energy management strategy most favourable for the case building studied was found to be a combination of optimizing the self-sufficiency and performing peak shaving. It would also be preferable to further develop the battery control to also take electricity prices and balance services into consideration. For this, AI and machine learning could be integrated in the control of the system. According to the case study results, the lithium ion battery technology had better potential for reaching economic profitability while the nickel metal hydride technology showed better potential in terms of environmental performance. The choice of battery technology and energy management strategy should however be adjusted to the customer specific demands and prerequisites.

Electric buses offer a range of benefits, including a drastic reduction of greenhouse gas emissions compared to personal transit, or to conventional diesel buses. Unfortunately, electric buses also require additional planning to ensure affordable and reliable operation. This thesis proposes two contributions that help to model and plan electric bus deployments, and generally examines how system-focused thinking is required for this application. First, a novel data driven method for estimating the energy consumption of a bus is presented and validated against 1 Hz driving data. Rather than requiring ad hoc data collection, or entire theoretical drivecycle patterns, this new method leverages existing low fidelity driving data from public transit feeds. This data driven method can be used to quickly and accurately model the driving patterns and energy consumption of a whole fleet of buses, as is demonstrated for a case study in Victoria, BC, Canada. Second, using the energy estimating methods previously mentioned, the electricity demand profile for a high-power electric bus charging hub is modelled for various locations and charging systems. Using this modelled demand profile, the potential for using a stationary energy storage system to reduce the peak power demand is investigated. The advantages of three different energy storage technologies (lithium ion, redox flow, and flywheel energy storage systems) are explored. Energy storage was found to be optimal for most charging scenarios modelled, with lithium ion providing the most economical solution for 65% of cases considered. Both the data drive energy estimation modelling, and the energy storage feasibility study constitute novel contributions to the literature. These contributions help to advance the knowledge surrounding electric bus planning and modelling, and help to underpin the systems level thinking required for electric bus deployments. / Graduate

The emergence of micropower-type applications such as self-powered sensors and miniaturized electronic systems has increased interest in on-chip electrochemical energy storage such as microsupercapacitors. Microsupercapacitors (MSCs) are high rate and high power yet miniaturized versions of macroscopic supercapacitors. MSCs with planar configuration have higher power density at potentially comparable energy density to thin-film batteries, while possessing essentially infinite cycle life. They could also offer compatible integration with smart electronic devices on an integrated chip (IC). In this dissertation, state-of-the-art microsupercapacitors based on Ti3C2Tx MXene and other pseudocapacitive electrode materials are proposed. The proposed strategies involve engineering both intrinsic properties of materials, fabrication methods and device architecture.

With the growing global population comes the ever-increasing consumption of energy in powering cities, electric vehicles, and portable devices such as cell-phones. While the power grid is used to distribute energy to consumers, the energy sources needed to power the grid itself are unsustainable and inefficient. The primary energy sources powering the grid, being fossil fuels, natural gas, and nuclear, are unsustainable as the economically-accessible reserves are continually depleted in exchange for detrimental emissions and air-pollutants. Cleaner, renewable sources, such as solar, wind, and hydroelectric, are intermittent and unreliable during the peak hours of energy usage, that is dawn and dusk. However, during waking hours and nighttime sleeping hours, energy consumption plummets resulting in substantial losses of potential energy as these intermittent energy providers do not have the infrastructure to store unused energy. Therefore, the research and development of efficient energy storage materials and renewable energy sources is critical to meet the needs of society in their fundamental operation while reducing harmful emissions. The research presented in this thesis focuses on selected energy storage materials and electrocatalysts as attractive technology for sustainable and benign renewable energy chemistry. Specifically, (1) theoretical studies on magnesium chloride / aluminum chloride electrolytes provide insight for further development of Mg batteries; (2) theoretical and experimental studies on viologen derivatives for organic redox flow batteries advance the development of these two-electron storage systems; and (3) a new iron(II) polypyridine catalyst that was found to electrochemically reduce CO2 to produce renewable fuels such as carbon monoxide (CO), hydrogen (H2), and methane (CH4), as well as promote the photochemical CO2-to-methane conversion with visible light.

L’évolution rapide des technologies de stockage d’énergie requiert la mise en point de nouveaux matériaux plus performants afin d’utiliser l’énergie relative à l’adsorption d’un fluide (eau) pour restituer l’énergie solaire préalablement stockée sur une période courte (heures) ou prolongée (inter saisonnière). Ces matériaux sont des sels inorganiques (chimisorption de l’eau), des adsorbants physiques ou des composites (sel inorganique dans une matrice poreuse).Les polymères de coordination poreux (PCPs) ou ’Metal-Organic Frameworks‘ (MOFs) sont des solides poreux hybrides dont la structure cristalline résulte de l’association de ligands organiques polycomplexants et de briques inorganiques interagissant par liaisons fortes. Les MOFs présentent une plus grande diversité chimique et structurale par rapport aux solides poreux inorganiques, ce qui permet de varier ‘à la carte’ leur caractère amphiphile, leur volume poreux, la taille et la forme des pores.Dans le cadre de cette thèse, nous avons étudié en premier lieu une série de MOFs poreux et stables dans l’eau, construits à partir des cations métalliques à haut degré d’oxydation (Fe3+, Al3+, Cr3+, Ti4+, Zr4+) et de ligands polycarboxylates. Nous avons choisi cette série de MOFs en tant qu’adsorbants physiques tout en évaluant dans un second temps leur capacité en tant que matrices d’immobilisation de sels inorganiques.L’étude des propriétés d’adsorption d’eau des MOFs seuls a démontré leurs grandes capacités d’adsorption conduisant ainsi à des densités énergétiques relativement élevées pour des systèmes en physisorption pure. La synthèse du MOF le plus performant de cette série (MIL-160(Al)) a été mise à l’échelle. Ce matériau a ensuite été mis en forme et ses propriétés de stockage de chaleur ont été évaluées dans un prototype de laboratoire (réacteur ouvert).Les applications de stockage inter saisonnier requièrent des matériaux avec une densité énergétique plus élevée par rapport à celle des adsorbants physiques et à ce titre, les composites qui résultent de l’encapsulation de sels inorganiques au sein de matrices poreuses sont intéressants en termes de densité énergétique et de stabilité chimique. De ce fait, le deuxième chapitre porte sur l’exploration d’une série de MOFs en tant que matrices d’encapsulation de sels afin de préparer des composites pour le stockage de l’énergie.Les MOFs sélectionnés permettent d’étudier l’influence de certains paramètres de la matrice (balance amphiphile, volume/taille des pores) sur les propriétés d’adsorption d’eau des composites. Les capacités de stockage énergétique des composites ont été évaluées dans les conditions d’utilisation d’un système de stockage d’énergie.Finalement la capacité de stockage élevée et la bonne stabilité de cyclage (adsorption-désorption) des deux meilleurs composites à base de matrices mésoporeuses (MIL-100(Fe) et MIL-101(Cr)) confirment l’intérêt de ces solides pour ce type d’application. / Nowadays the forceful development of the energy storage technologies requires the design of novel adsorbents. Energy reallocation concept allows storing renewable solar energies at short (hours) and long term (inter seasonal) using adsorption method. Energy storage materials can be divided in chemical storage materials, physical storage materials and composite materials (inorganic salt in porous matrix).Metal-Organic Frameworks (MOFs) are a new class of porous crystalline materials that are built from an inorganic subunits and organic ligands defining an ordered structure with regular accessible porosity. In comparison with other classes of porous solids, MOFs display a higher degree of versatility (chemical composition, topology) and tunable amphiphilic character, pore volume, pore size, shape, etc.In this work, we have studied a series of water stable porous metal carboxylates made from cheap metal cations (Fe3+, Al3+, Cr3+, Ti4+, Zr4+) and polycarboxylate linkers as pure physical adsorbents and as host matrices of salts for the design of composite adsorbents. The study of the adsorption properties of pure MOFs in conditions of thermal energy storage system has shown high water adsorption capacity and high energy storage densities.The most promising MOF from this series namely MIL-160(Al) has been prepared at large scale, processed as pellets and then evaluated in open-reactor prototype.The second chapter has been focused on the first exploitation of a series of Metal Organic Framework (MOFs) as host matrices of salts for the preparation of composite sorbents for heat storage application.Indeed, inter seasonal energy storage requires materials with higher energy densities (composite and chemical storage materials), than physical sorption materials can offer. We have selected a series of MOFs differing by their amphiphilic balance and pore volume in order to investigate the impact of such physico-chemical properties on the water sorption properties of composites. The energy storage capacity of salt-MOFs composites has been evaluated in representative conditions of thermal storage devices. The high energy storage capacity and good stability under numerous adsorption-desorption cycles for two composites based on mesoporous MIL-100(Fe) and MIL-101(Cr) confirm the potentiality of such composites for this application.