The development of science and technology have provided a lifestyle completely dependent on energy consumption. Devices such as computers and mobile phones are good examples of how our daily life depends on electric energy. In this scenario, energy storage technologies emerge with strategic importance providing efficient ways to transport and commercialize the produced energy. Rechargeable batteries come as the most suitable alternative to fulfill the market demand due to their higher energy- and power- density when compared with other electrochemical energy storage systems. In this context, during the production of this thesis, promising compounds for advanced batteries application were investigated from the theoretical viewpoint. The framework of the density functional theory has been employed together with others theoretical tools to study properties such as ionic diffusion, redox potential, electronic structure and crystal structure prediction. Different organic materials were theoretically characterized with quite distinct objectives. For instance, a protocol able to predict the redox potential in solution of long oligomers were developed and tested against experimental measurements. Strategies such as anchoring of small active molecules on polymers backbone have also been investigated through a screening process that determined the most promising candidates. Methods such as evolutionary simulation and basin-hopping algorithm were employed to search for global minimum crystal structures of small molecules and inorganic compounds working as a cathode of advanced sodium batteries. The crystal structure evolution of C6Cl4O2 upon Na insertion was unveiled and the main reasons behind the lower specific capacity obtained in the experiment were clarified. Ab initio molecular dynamics and the nudged elastic band method were employed to understand the underlying ionic diffusion mechanisms in the recently proposed Alluaudite and Eldfellite cathode materials. Moreover, it was demonstrated that electronic conduction in Na2O2, a byproduct of the Na-O2 battery, occurs via hole polarons hopping. Important physical and chemical insights were obtained during the production of this thesis. It finally supports the development of low production cost, environmental friendliness and efficient electrode compounds for advanced secondary batteries.

This dissertation aims to use a system thinking approach to describe and evaluate the Lead-Acid Battery Recycling Program in British Columbia, compare it with other provincial regulated recycling programs and identify strategies on how it can be improved. The research is presented in the manuscript based format, comprised of four interrelated chapters. Following the introduction, chapter 2 describes a multiple regression analysis to assess how various factors identified by informed stakeholders have contributed to recycling rate in 14 transportation zones from 1995 to 2005. This study demonstrates that the existing recycling scheme ineffectively promotes recycling as it has achieved an average of 75% over the past 13 years with large fluctuations among transportation zones. The regression also shows that recycling rate of transportation zones are not highly influenced by LME lead prices and Transportation Incentive (which can be explained by the strong market power of the recycling plants responsible for setting up the price of scrap lead to which the collectors respond). Chapter 3 identifies key components that influence the performance of varied recycling systems based on a comparative analysis of provincial recycling systems informed by expert interviews. In chapter 4, comprehensive evaluation criteria for the lead-acid battery recycling program is developed based on objectives and performance measures elicited through an extensive stakeholder consultation process with various individuals and organizations. Fundamental objectives identified by stakeholders include: reduce environmental impacts, reduce occupational health impacts, reduce net costs, increase equity in resource consumption patterns and increase systematic learning. In chapter 5, we use multiple criteria decision analysis (MCDA) to design and assess effective recycling strategies to meet societal objectives previously identified in the chapter 4. Recycling strategies were compiled using the results of chapter 3. The results reveals that the optimal policy for the lead-acid battery recycling system combines a return to retailer program financed through an advanced disposal fee included in the battery price in combination with increased plant or recycling capacity domestically. This research also provides relevant contributions to the refining and application of value-focused thinking and decision analysis methodologies. / Applied Science, Faculty of / Mining Engineering, Keevil Institute of / Graduate

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.

This thesis first uses physical scale models to investigate solid-state phenomena - surface layer formation, solid-state diffusion of lithium, electrochemical reactions at the solid-electrolyte interface, as well as homogeneous chemical phase change reactions. Evidence is provided that surface layer formation on the magnetite, Fe3O4, electrode can accurately be described mathematically as a nucleation and growth process. To emulate the electrochemical results of the LiV3O8 electrode, a novel method is developed to capture the phase change process; this method describes phase change as a nucleation and growth process. The physical parameters of the LiV3O8 electrode: the solid-state diffusion coefficient, phase change saturation concentration, phase reaction rate constant, and exchange current density, are all quantified and the agreement with experimental results is compelling. Electrochemical evidence, corroborated by results from density functional theory, indicate that delithiation is a more facile process than lithiation in the LiV3O8 electrode. Further investigation of the LiV3O8 electrode is undertaken by coupling the crystal scale model to electrode scale phenomena. Characterization of the LiV3O8 electrode by operando EDXRD experiments provides a unique and independent set of observations that validate the previously estimated physical constants for the phase change saturation concentration and phase change reaction rate constant; they are both found to be consistent with their previous estimates. Finally, it is observed that anodic physical phenomena are important during delithiation of the cathode because the kinetics at the anode become mass-transfer limited. Finally, it is illustrated that coupling physical models to data science and algorithmic computing is an effective method to accelerate model development and quantitatively guide the design of experiments.

After three decades of commercialization, graphite remains the preferred active material for intercalation-type Li-ion battery anodes. Still, the characterization of staging continues to be elusive at the sub-micro- and nano-scales, the typical dimensions of graphite crystallites. Here, the intercalation of Al-based anions in graphitic materials was studied using X-ray powder diffraction (XRD) and Raman spectroscopy. While, in the first case, the analysis was done ex-situ and in mm3-samples, a more localized view was provided by the laser probe which could, furthermore, interrogate the electrochemical process in real-time (in-situ). To do this, an electrochemical cell for Raman studies was custom-made for Al batteries working with non-aqueous electrolytes. Two C materials were used: natural graphite (NG) and processed expandable graphite (EG). Owing to the smaller flake size, higher graphitization degree and larger crystallites of the NG, the Al/NG cells exhibited better performance than the Al/EG ones. Interestingly, discrepancies were observed in the stage numbers estimated from XRD and Raman. These were thought to arise from the, respectively, long- and short-range atomic order scales that are analyzed by those two techniques. To confirm this, in-situ Raman multi-point studies were performed. The results show the presence of domains with mixed stage graphite intercalation when the cells were fully charged, explaining the staging discrepancies.

Lithium-ion batteries are of great importance for today's society. The state-of-the-art batteries that are used today use a fluorinated electrolyte that contains the salt LiPF6 and acts as both a safety hazard and an environmental issue due to its ability to form the toxic gas hydrogen fluoride (HF). This project aims to find a fluorine-free electrolyte that can be used in silicon-based lithium-ion batteries to make them more environmentally friendly without detriment to the electrochemical performance. To do so, an additive that may form a solid electrolyte interphase (SEI) stable enough to allow a fluorine-free electrolyte to replace the ones used today is sought for. The salt of interest is lithium  bis(oxalato)borate (LiBOB). Based on previous research electrolytes using LiBOB in either the solvent γ-Butyrolactone (GBL) or a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) are examined. The additives used are vinylene carbonate (VC) and 1,3,2-dioxathiolane 2,2-dioxide (DTD). Techniques used are cyclic voltammetry, linear sweep voltammetry, galvanostatic charge and discharge, X-ray photoelectron spectroscopy and scanning electron microscopy.  The cells using GBL as solvent have cycled very poorly during this project while LiBOB in EC:EMC + VC shows the most promising results, with highest capacity retention and less amount of degraded LiBOB during the first charge. It is also to be noted that both EC:EMC based electrolytes provide the formation of a passivating solid electrolyte interface (SEI) and are of interest for further investigation based on the results obtained during this project.

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This thesis deals with processing the current issue of trends in on-grid photovoltaic system with accumulation. It examines the posibility of accumulation of photovoltaic systems, analyzing their strengths and weaknesses in the practical deployment. It compares the different storage technologies based on indicators of cycles, durability and price ranges. The practical part deals with the technical design of hybrid power system and then comparing with the standard on-grid system in technical and economical point of view.

Stricter regulations concerning emissions from road traffic and increasing fuel prices has lead to an interest in hybrid electric vehicles (HEVs). Today even manufacturers of heavy duty vehicles are introducing hybrid alternatives. Batteries are expensive and a complex part in HEVs, and ways of determining a battery’s capacity is a current research topic. When a battery is used it ages, i.e. the capacity decreases and the impedance rises. Since battery cost is high, it is important to be able to determine battery ageing properly. The focus of this master thesis has been on impedance measurement methods for Li-ion batteries. The work has been carried out in cooperation with Scania CV AB. When a battery is aged, the impedance increases. Monitoring ageing mechanisms could enable increased lifetime of the batteries through optimized usage in for example heavy duty hybrid vehicles. In this work, Hybrid Pulse Power Characterization (HPPC) has been compared with Electrochemical Impedance Spectroscopy (EIS). A major difference between these methods is that HPPC uses pulses of high direct current, whereas a small alternating current perturbation is used in EIS. EIS give information about different mechanisms influencing the battery impedance, e.g. internal resistance and charge transfer resistance, but requires expensive and complex laboratory equipment. HPPC gives less detailed information about the impedance, but is more similar to field applications for a vehicle. A literature survey showed that much research is conducted on in-situ impedance measurements of batteries. One example is the long-term demonstration of an Impedance Measurement Box (IMB), which is currently carried out at Idaho National Laboratory. The method uses a sum-of-sines signal consisting of octave harmonics for a fast impedance measurement with good precision. The results showed a good correlation with laboratory EIS measurements. The experimental part of this project suggest that a linear correlation  exists between the discharge resistance from HPPC measurements and the sum of internal resistance and charge transfer resistance from EIS measurements. The linear fitting did not have very good R-squared value but a residual analysis showed that the residuals were randomly scattered around zero, indicating that a linear fitting is suitable. However, the precision of the results is too poor for the correlation to be useful in a real HEV application. Additional work to improve the linear fitting is recommended. Furthermore, it was showed that AC-components have to be used as a measurement signal in order to measure the complex impedance of a battery. A paired t-test was conducted in order to study if noise could be used as that signal for a battery under load. The impedance at 100 Hz was calculated, which corresponds to the second harmonic of the power grid. The difference between this impedance and the impedance measured at 100 Hz with EIS was statistically tested. For shorter times pans (in this case 20 milliseconds) after applying the DC pulse, using noise cannot be ruled out for measuring a battery’s impedance under load. But for longer time spans after applying the DC pulse (in this case 1.3 seconds), there was a significant difference between the two methods. Concentration gradients caused by mass transfer limitations could be causing this effect.