Doctor of Philosophy, Case Western Reserve University, 2006, Chemical Engineering

Neuroprosthetic devices that electrically stimulate paralyzed muscles require implantable power sources with exceptional cycle life, safety, and sufficient energy and power density. Of the rechargeable battery technologies, lithium ion batteries have the highest energy density; however, they have limited cycle life of about 1000 cycles. Nickel-hydrogen batteries, currently used in space applications are remarkable for long cycle life (40,000) and low maintenance; however they utilize high hydrogen pressures (60 atm) making them unsuitable for implantable applications. The present work involves design and development of low pressure nickel-hydrogen batteries (1 atm) by utilizing a metal hydride (MH) to store hydrogen, rather than as a negative electrode in the nickel-metal hydride battery. A method to increase the exchange current density of the negative platinum electrode using cyclic voltammetry was developed. A nickel mesh was chosen as the current collector because of its low resistance and stability in alkaline solutions. The tested separators, zirconium oxide and polypropylene, were not significantly different from each other. A pasted type nickel hydroxide electrode was fabricated by two means: screen printing and spatula pressing. The mechanism of electrode formation, the effect of different formation rates with and without overcharge and the effect of binder and nickel content on utilization were studied. Addition of filamentary nickel to the electrode increases the utilization by 10% by decreasing the oxygen evolution. A low pressure nickel-hydrogen battery with and without MH was assembled. Charge and pressure data were analyzed to study the oxygen evolution, the recombination reaction and the self discharge of the cell. Oxygen evolution increases with the depth of charge; however the evolved oxygen recombines completely – 70% during charging and the remainder during the first hour of the rest period. About 40-45% hydrogen from the metal hydride was used a (open full item for complete abstract)

Committee: Jesse Wainright (Advisor) Subjects: Energy; Engineering, Chemical

Doctor of Philosophy, The Ohio State University, 2022, Chemistry

Increasing concerns about carbon emissions has led to the global adoption of renewable energy initiatives. Direct integration of renewable energy sources, however, is difficult because of the intermittency of such sources. Furthermore, direct integration would overload the grid and lead to blackouts. Thus, grid-scale electrical energy storage is required to store and provide energy on-demand. Redox flow batteries have attracted attention as a scalable, inexpensive storage technology. Flow batteries store energy in solvated, redox-active electrolytes, as opposed to conductive, solid materials. These solutions are stored in separated reservoirs and are flowed to the electrochemical cell to cycle the redox-active compound. Energy stored in this fashion decouples energy and power, which allow for increased operational control. While many electrolytes exist, few electrolyte examples have achieved commercialization because of low solubility and low cell voltage. Redox-targeting flow batteries have emerged as an improvement to classic flow technology. Rather than storing energy in solution, redox -targeting flow batteries store energy in an insoluble solid while a solubilized electrolyte serves to shuttle electrons from the electrochemical cell to the solid. This strategy serves to combine the high energy density of solid-state batteries and scalability of flow batteries. Current redox targeting technology is mainly limited to the use of inorganic solid materials. These materials are cycle by an intercalation mechanism, which requires low current densities that lead to long cycle times. Furthermore, pairing shuttles with these materials are difficult because of distinct redox potentials and electron transfer rates of these solids. Our efforts focused on the development of an all-organic redox targeting flow battery. Organic materials generally do not operate based on intercalation mechanisms and the synthetic flexibility of organic compounds allow for the fin (open full item for complete abstract)

Committee: Christo Sevov (Advisor); Yiying Wu (Committee Member); Jovica Badjic (Committee Member) Subjects: Chemistry; Energy

Master of Science in Engineering, University of Akron, 2018, Mechanical Engineering

Battery Thermal Management Systems are necessary for the overall efficiency and life cycle of vehicle as well safety of passengers and vehicle, as elevated operating temperatures have adverse effect on the efficiency, life cycle and safety of the Li-ion battery packs. The operating temperature prescribed by many studies for improved performance and better life cycle of Li-ion batteries is around 25°C. In some worst case scenarios, high operating temperature may lead to thermal runaway in the battery, causing immense amount of heat generation, even leading to an explosion. To avoid all these dangerous events, battery thermal management is utilized to regulate the temperature of the battery pack. In this thesis, a novel battery thermal management system based on liquid cooling principle is proposed. The system involves dual purpose cooling plate for prismatic Li-ion batteries, which can maintain the temperature under normal conditions as well as mitigate the heat generated during thermal runaway. An experiment was performed on the prismatic Li-ion battery to measure the heat generation trends. The battery was discharged at 5C to replicate aggressive conditions. The data for maximum heat flux generated in the Li-ion battery was obtained. An estimated amount of heat generated during thermal runaway was calculated. A conjugate heat transfer method was used to simulate the cooling plates for normal operation and thermal runaway. The plates were simulated with two flow rates for normal operation and three flow rates for thermal runaway. Three different designs of cooling plates were compared on the basis of surface temperature, pressure drop and flow rate. The final design was selected based on the comparison with the rest of the cooling plates. The selected cooling plate can: • Maintain the temperature of battery below 25°C during normal operation. • Dissipate the maximum possible heat generated during thermal runaway and bring the temperature to less than 80°C. • M (open full item for complete abstract)

Committee: Siamak Farhad (Committee Chair); Gopal Nakarni (Committee Co-Chair); Alper Buldum (Committee Member); Reza Madad (Committee Member) Subjects: Mechanical Engineering

Master of Science (MS), Ohio University, 2024, Mechanical Engineering (Engineering and Technology)

In recent years, lithium-ion batteries (LIBs) have played an essential role in nowadays energy storage system, especially electric vehicles (EVs) and portable electronics because of its high energy density and long cycle life [1, 2]. However, one of the biggest challenges is how to guarantee their dependability and trustworthiness. In the present investigation, Acoustic Emission (AE) and Ultrasound Testing (UT) techniques are systematically employed to verify probable critical defects in the LIBs. Where AE technology is able to record the stress waves produced by the growth of the defects, UT uses high-frequency sound waves to penetrate the batteries and provide an indication of the internal voids. The performances of these approaches were systematically tested on as-received, pre-damaged and cold-soaked batteries. Different AE and UT activity patterns were shown in the results under various environmental conditions that influenced battery performance. Combining Acoustic Emission (AE) and Ultrasound Testing (UT) with clustering and outlier analysis machine learning algorithms improved defect detection effectiveness. Such research highlights that AE and UT can be robust noninvasive techniques for on-line health monitoring of LIBs that should aid in maintaining the longevity and operability of LIBs.

Committee: Brian Wisner (Advisor) Subjects: Acoustics; Mechanical Engineering

Doctor of Philosophy, The Ohio State University, 2024, Mechanical Engineering

The emergence of electric vehicles (EVs) along with the movement toward “zero-emission” has put the lithium-ion batteries (LIBs) system as a pivotal technology for a sustainable future. While the LIBs offer high energy density, extended cycle life, and fast charging capabilities, the battery system always has been incorporated with safety concerns due to the flammable liquid electrolytes used for traditional LIBs. Solid electrolytes (SEs) offer as a promising solution to replace liquid electrolytes, enhancing safety and performance. However, there are challenges associated with SEs, including low ionic conductivity of SE materials, large interface resistance, chemical instability between electrode and electrolyte, and Li-dendrite growth, necessitate thorough investigation. Especially, the interface between cathode and solid electrolyte materials is a critical focus, requiring compatibility with SEs in the selection of a cathode active materials (CAM) for the development of all-solid-state battery system. This dissertation explores various types of cathode materials for integration into all-solid-state Li-ion battery systems. For example, layered cathode materials with various Ni/Mn/Co compositions (LiNixMnyCo1-x-yO2 (NMC)) were explored, revealing the degradation behavior against the moisture impact, which is a crucial factor for the practical applications. Li-Mn-rich cathode has prominent features of high energy and power density. While it exhibits large irreversible capacities and rapid degradation over cycles, strategies such as core-shell synthesis and fluorine substitution were applied to address the defects. Meanwhile, aluminum substituted spinel cathode LiCo1-xAlxO2 (x = 0 – 0.3) was introduced along with its “zero-strain” property, which is an attractive feature for the all-solid-state battery application. It was confirmed that Al-doping can effectively suppress the evolution of impurity phase and structure decomposition over extended cycles. On the other (open full item for complete abstract)

Committee: Seung Hyun Kim (Committee Member); Jay Sayre (Committee Member); Jung-Hyun Kim (Advisor) Subjects: Automotive Engineering; Automotive Materials; Chemical Engineering; Materials Science; Mechanical Engineering

Doctor of Philosophy (Ph.D.), University of Dayton, 2021, Electrical Engineering

Lithium-ion batteries (LIBs) have been widely used in electric vehicles, portable devices, grid energy storage, and space because of their high energy densities, power density, and high cycle-life. Since the commercialization of LIBs in 1991 by Sony Inc., the energy density of LIBs has significantly increased, closing to ~250 Wh kg-1 (900 kJ kg-1). However, if operated improperly, the stored energy can be abruptly released in the form of fire or explosions. Accidents involving battery fires and explosions in cell phones, laptops, electric vehicles, and airplanes have occurred often in recent years. Some have caused severe threats to human life and health and have led to numerous product recalls by manufacturers. These incidents underline the urgent need to develop methods and materials to improve the safety of LIBs. LIBs using the traditional carbonate-based organic liquid electrolytes (OLE) in which organic solvents are flammable and prone to catching fires limits its operation when the battery is operated beyond 65 °C. In this dissertation, the primary focus is to replace the flammable components of LIBs with new materials that have little to no heat release, so that in the event of an abuse condition, there will be less fire or smoke, to begin with. Battery separators play a crucial role in determining LIB safety. The primary function of the separator is to prevent physical contact between the anode and cathode, thereby preventing electrical shorting while facilitating ion transport in the cell. Any electrical (electronic) connection between the two electrodes (cathode and anode) can create a short circuit. An electrical short circuit can lead to a sudden discharge and consequent cell heating that may ultimately result in battery thermal runaway and potentially fire and even explosion due to the increasing temperature inside the LIB. Short circuits between battery cell electrodes can occur for several reasons, such as lithium dendrite (wire of metallic lithium) (open full item for complete abstract)

Committee: Jitendra Kumar (Committee Chair); Vikram Kuppa (Committee Member); Guru Subramanyam (Committee Member); Feng Ye (Committee Member) Subjects: Electrical Engineering

Master of Science, The Ohio State University, 2020, Mechanical Engineering

Li-ion batteries have been identified as a key player among energy storage systems with higher energy and power densities coupled with cost-effectiveness compared to erstwhile cell chemistries. As the usage of energy storage systems in electrified vehicles increases, so will the number of battery packs dismissed from the vehicular applications once they cannot satisfy energy and power requirements as specified by the OEMs. The disposal of these battery packs after their vehicular usage has been a major concern, but it is also noted that these battery packs still retain a large amount of energy and power capability, making it suitable for other applications that extend the operational lifetime of battery packs. Applications that prolong the usage of battery packs after vehicular applications are termed as 'second-life' and currently, stationary energy storage is seen as the most prevalent choice of second-life application. Battery systems inherently degrade, much like any other physical system. Degradation may refer to the reduction in performance, durability, and reliability of a system. Information regarding the physical degradation of a battery pack throughout its operational lifetime gives insights into how long the battery can sustain a given operation. Model-based methods for understanding battery degradation have been extensively reported in the literature, having differences in prediction fidelity, model complexity and computational cost. In this thesis, a comparative analysis between two state of the art aging models is applied to several second-life applications. The considered models are classified as semi-empirical and empirical based on their theories for model development. The comparison considers calibration procedures, model structure, fidelity, and capability of extrapolating outside the calibration range. The availability of experimental data for calibration and validation of these two models also has a profound effect on their estimation perform (open full item for complete abstract)

Committee: Giorgio Rizzoni (Advisor); Yann Guezennec (Committee Member) Subjects: Automotive Engineering; Mechanical Engineering

Doctor of Philosophy, Case Western Reserve University, 2017, Chemical Engineering

For grid-scale energy storage applications, iron-based hybrid flow batteries have advantages of safety, sustainability and low-cost. Still, several challenges such as device lifetime and efficiency have limited their development. In this work, a new type of hydrogen-ferric ion recombination reactor based on catalyzed, three-dimensional felt is proposed in order to maintain chemical balance in the electrolytes and hence improve the battery stability and lifetime. Cyclic voltammetry (CV) and electrochem- ical impedance spectroscopy (EIS) were used to identify a diffusion-limited hydrogen oxidation current near 0.3 psig of hydrogen partial pressure and show that the perfor- mance can be improved with increasing hydrogen pressure up to about P H 2 = 10 psig. Also, pressure-based measurements showed that high rates of hydrogen recombina- tion (greater than 20 mA cm -2 based on the geometric area and greater than 100 mA cm -2 based on the cross-sectional area) were possible using a floating, membrane-less reactor design. A flow battery model that incorporates the hydrogen evolution side-reactions and chemical rebalancing was developed using a system of differential and algebraic equations (DAE). A good agreement between simulated and measured pressure profiles was obtained for an all-iron flow battery operating at ±100 mA cm -2 . Effects of separator porosity and thickness were simulated, showing how increased thickness and reduced porosity can cause higher pH in the negative electrolyte and hence reduced hydrogen generation. Lastly, a new hybrid flow battery based on mixed, lightly acidic electrolytes was investigated. By using the anomalous codeposition (ACD) phenomenon, it was possible to electrodeposit nearly pure zinc from mixed ZnCl 2 -FeCl 2 electrolytes. The cell was shown to provide 17 % higher voltaic efficiency and 40 % higher power density compared to an all-iron battery operating under the same conditions. A zinc-iron chloride flow battery (open full item for complete abstract)

Committee: robert savinell (Committee Chair); jesse wainright (Committee Member); rohan akolkar (Committee Member); gary wnek (Committee Member) Subjects: Chemical Engineering; Chemistry; Energy; Engineering

Master of Science in Renewable and Clean Energy Engineering (MSRCE), Wright State University, 2024, Mechanical Engineering

Lithium-ion batteries are an integral component of energy storage systems for renewable energy applications owing to their high energy density. Extensive research has therefore been carried out, utilizing both experimental and computational methods, to aid in a deeper understanding of lithium-ion batteries. Challenges related to efficiency, safety and thermal management persist, particularly during high current draw, extreme temperature conditions and extreme dynamic current operation such as in electric vehicles. This thesis work presents an electrochemical-thermal model of a lithium-ion battery that simulates and analyzes the variation of electrical behavior, chemical behavior and thermal behavior. The electrochemical model is developed by computationally finding solutions to a set of partial differential equations that describe electrochemical and thermal processes in the anode, separator and cathode. These equations are mass conservation in electrodes (cathode and anode), charge conservation in electrodes, mass conservation in the electrolyte, charge conservation in the electrolyte, and a thermal energy balance throughout the battery. In addition, the Butler Volmer equation is used to describe the exchange of lithium ions between the solid electrodes and the electrolyte. The solutions to these equations are found using a finite volume numerical procedure implemented in MATLAB. This computational model builds on the work of Borakhadikar [1] who did not deal with the thermal issue. The results obtained by the developed program are validated against those from Smith and Wang [2] and Gu and Wang [4]. Once it is determined that the program is producing good results, a number of other results are generated for the reader to review. Profiles of the lithium-ion concentrations, profiles of the voltage, and profiles of the temperature across the battery at a given discharge level are presented. In addition, the voltage output and temperature as a function of time are g (open full item for complete abstract)

Committee: James Menart Ph.D. (Advisor); Henry D. Young Ph.D. (Committee Member); Hong Huang Ph.D. (Committee Member) Subjects: Energy; Engineering; Mechanical Engineering

Doctor of Philosophy (PhD), Wright State University, 2024, Environmental Sciences PhD

N-heterocyclic carbenes (NHCs), a characteristic 5-membered ring structure, contain a carbene carbon and at least one nitrogen atom. The presence of nitrogen atoms in the cyclic structure has two effects on its electronic structure: it withdraws σ-electrons and donates π-electrons to the carbene carbon, significantly enhancing the electronic richness and stability of the carbene center. Incorporating heteroatoms like sulfur, oxygen, or phosphorus into the NHC framework has paved the way for advanced developments in their structural properties. The incorporation of additional aromatic ring/heteroatom into NHC offers novel pathways for functionalization, ultimately broadening its scope of potential applications. The primary goal of this research project is to investigate the synthesis of metal-free tetrathiafulvalene annulated benzimidazolium (TTF-BzIm) salts and their possible application in redox-flow batteries (RFB) to be more eco-friendly. Additionally, the project aims to explore the properties and applications of a novel trithiocarbonate (TTC) annulated benzimidazolium (BzIm) carbene and its metal complexation studies. The beginning stages of the project focus on finding an efficient synthesis route to prepare trithiocarbonate-annulated benzimidazole NHC precursors, and their structural confirmation will be carried out by various characterization techniques such as Nuclear Magnetic Resonance (NMR), High-resolution mass spectrometry (HR-Mass), Fourier-transform infrared spectroscopy (FT-IR). Further, this new class of NHC precursors is complexed with transition metals to study their electrochemical behavior using Cyclic voltammetry (CV) and donor property in the presence of trithiocarbonate NHC backbone. NHCs are valued in material fabrication due to their stable metal-carbene bonds and ability to facilitate electron transfer. These beneficial properties stem from their ease of synthesis, the availability of synthetically modified ligands for various catalytic (open full item for complete abstract)

Committee: Kuppuswamy Arumugam Ph.D. (Committee Chair); Steven R. Higgins Ph.D. (Committee Member); Jitendra Kumar Ph.D. (Committee Member); Amit Sharma Ph.D. (Committee Member); Ioana E. Pavel Ph.D. (Committee Member) Subjects: Chemistry; Environmental Science

Doctor of Philosophy, University of Akron, 2024, Chemistry

Electrochemical methods, which collect data on potential and/or current, are useful techniques that have been utilized in various fields, including energy storage, medicine, and biology. My PhD research employs electrochemical methods in three areas: investigating redox flow batteries (RFBs), understanding heterogeneous electron transfer (ET) theories, and establishing a connection with machine learning (ML). This dissertation is organized into three parts accordingly. The first part of this dissertation (Chapters II through V) is the investigation of ferrocene-based aqueous redox flow batteries (ARFBs). The development of RFBs has gained significant attention in recent years due to the growing demand for efficient and reliable energy storage systems. ARFBs, which use water-soluble compounds, have become increasingly popular because of their lower electrolyte resistance, reduced cost, enhanced safety, and lower environmental impact. Ferrocene (Fc), which can be modified to be soluble in water, possesses a high reversibility and electron transfer rate, making it an ideal candidate for ARFBs. During my Ph.D. period, several new water-soluble sulfonated Fc based ARFBs were characterized, including 1,1′-bis(sulfonate)ferrocene dianion disodium (1,1'-FcDS), ferrocene-1,1'-bis(sulfonate)ferrocene dianionic salts with varying imidazolium cations, pyridinium salts of the ferrocene bis(sulfonate) dianion (FcPyr), 3-((ferrocenyl)methyldimethylammonio)-1-propanesulfonate (Fc3), and 4-((ferrocen-yl)methyldimethylammonio)-1-butanesulfonate (Fc4). The suitable structures of Fc for ARFB applications have been revealed. The second part of this dissertation focuses on understanding heterogeneous electron transfer. Various electroanalytical techniques, including steady-state current, cyclic voltammetry (CV), and differential pulse voltammetry (DPV), were simulated in COMSOL Multiphysics, and the results are presented in Chapter VI. Chapter VII describes the ET processes in a non- (open full item for complete abstract)

Committee: Aliaksei Boika (Advisor); Christopher Ziegler (Committee Member); Chrys Wesdemiotis (Committee Member); Chunming Liu (Committee Member); Zhong-Hui Duan (Committee Member) Subjects: Chemistry; Computer Science; Education; Energy

Doctor of Philosophy, Case Western Reserve University, 2023, Chemical Engineering

The work of my Ph.D. thesis focuses on understanding the physical and electrochemical properties of deep eutectic solvents (DESs) and concentrated hydrogen bonded electrolytes (CoHBEs) through experiments concerning their use as electrolytes for redox flow batteries. My work aims to provide a fundamental understanding of how DES components govern bulk properties and double-layer structure with the ultimate goal of leveraging the gained knowledge to design new electrolytes for flow battery applications. Thesis Goals ● Bulk liquid properties: To determine how molecular structure and composition of DES components affect bulk macroscopic properties such as density, viscosity, and conductivity. ● Electrode-electrolyte interface: To develop a physical model of the voltage-dependent ion accumulation in DESs and CoHBES near the electrode and to identify surface species during the course of a redox reaction. ● Redox active organics: To study redox active organics as potential candidates for redox material in a CoHBE-based flow batteries. Chapter 3: In Chapter 3, we investigate the differential capacitance of choline chloride (ChCl) and ethylene glycol (EG) as a function of potential and composition using electrochemical impedance spectroscopy (EIS) on glassy carbon, Au, and Pt electrodes. We compared these results to glyceline (ChCl:glycerol, 1:2). The capacitance-potential curves on glassy carbon were best explained by the modified Gouy-Chapman model. We observe a dampened U-shape similar to dilute electrolytes. However, the presence of significant ionic and hydrogen bonding interactions in these electrolytes introduced ambiguity regarding the point of zero charge, where the capacitance weakly depended on potential. When using Au electrodes, we observe an increase in capacitance due to desolvation and specific adsorption of Cl ions. Conversely, with Pt electrodes, we observe increased capacitance with decreasing Cl concentrations. These results indicate that deep e (open full item for complete abstract)

Committee: Burcu Gurkan (Advisor); Clemens Burda (Committee Member); Robert Warburton (Committee Member); Robert Savinell (Committee Member) Subjects: Chemical Engineering

Doctor of Philosophy, Case Western Reserve University, 2024, Chemical Engineering

Ionic liquids (ILs) are salts that are liquids at room temperature and are promising materials for use as electrolytes for lithium battery applications. The state-of-the-art organic carbonate (OC) electrolytes pose concerns due to their volatility, which, under abusive conditions, lead to the thermal runaway in Li-ion batteries (LIBs). Secondly, OCs are unreliable in secondary battery applications for Li-metal batteries (LMBs), as rapid dendrite growth on the Li-metal anode leads to short circuits. Contrary, ILs provide wide electrochemical windows, high lithium salt solubility, stable Li-metal anode cycling, and importantly, have negligible volatility, significantly reducing safety concerns. However, as ILs are comprised entirely of charged species, solvation and transport of Li-ions becomes complicated and sluggish. Typically, multiple IL anions solvate Li+ and result in Li-solvates that are negatively charged, leading to transport of Li+ in the wrong direction. Therefore, it is crucial to tune the properties of IL electrolyte to allow Li+ to free itself from its first solvation shell to improve its transport in the bulk, leading to improved electrochemical performance. This thesis work demonstrates the design of IL electrolytes comprised of multiple IL anions, asymmetric IL anions, and IL mixtures with hydrofluoroethers (HFEs) to improve upon Li-ion transport in conventional IL electrolytes and to mitigate the safety concerns of OC-based electrolytes. Specifically, a fundamental understanding of how Li+ is solvated in multicomponent IL electrolytes is examined through various spectroscopy techniques and simulations. Further, the solvation structure of Li+ is linked to its transport behavior by examining the solvation strength through ab initio calculations and measuring the transport properties including viscosity, diffusion coefficients, and Li+ transference. Thus, the structure-property relations are developed as a function of composition and supported (open full item for complete abstract)

Committee: Burcu Gurkan (Advisor); Robert Savinell (Committee Member); Rohan Akolkar (Committee Member); Shane Parker (Committee Member) Subjects: Chemical Engineering

Doctor of Philosophy (Ph.D.), University of Dayton, 2023, Electrical Engineering

Lithium-ion batteries (LIBs) have transformed modern electronics and rapidly advancing electric vehicles (EVs) due to high energy, power, cycle-life, and acceptable safety. However, the comprehensive commercialization of EVs necessitates the invention of LIBs with much enhanced and stable electrochemical performances, including higher energy/power density, cycle-life, and operation safety but at a lower cost. An unprotected lithium-ion battery (LIB) cell cathode using lithium metal anode and organic carbonate liquid electrolyte undergoes significant structural damage during the cycling (Li+ intercalation/ deintercalation) process. Also, a bare cathode in contact with a liquid electrolyte forms a resistive cathode electrolyte interface (CEI) layer. Both the cathode structure damage and CEI lead to rapid capacity fade. Different strategies have been used to mitigate the degradation of LIB electrodes, including designing electrolytes to enhance SEI/CEI formation, cycle stability, interface engineering with protective coatings to prevent the breakdown of active material particles during cycling, composition control of the electrode particles, synthetic optimization to control particle morphology, the use of composites made from conductive scaffolds and active materials and designing new electrode architectures to overcome volume changes and enhance transport properties. Cathode surface modification has been used to reduce CEI formation and structural damage, improving capacity retention, cycle life, energy density, power density, and safety of a LIB. Recently, the coating of the cathode with an intermediate layer (IL), which is transparent to Li+ conduction but impermeable to electrolyte solvent, has been developed to minimize CEI formation and structural damage. IL based on Li+ insulating ceramics, such as aluminum oxide (Al2O3), tin oxide (SnO2), and magnesium oxide (MgO), has been developed but to limited success in mitigating the above cathode degradation. The (open full item for complete abstract)

Committee: Dr. Jitendra Kumar (Committee Chair); Dr. Guru Subramanyam (Committee Member); Dr. Feng Ye (Committee Member); Dr. Vikram Kuppa (Committee Member) Subjects: Electrical Engineering; Energy; Engineering

Master of Science in Materials Science and Engineering (MSMSE), Wright State University, 2023, Materials Science and Engineering

The rapid advancement of technology has resulted in a greater need for effective energy storage systems to meet the demands of the transportation and electronics industries. Among various energy storage systems, batteries are the most widely used, primarily because of their ability to store significant amounts of energy. In addition, lithium-ion batteries are prevalent for powering portable electronic devices due to their long cycle life, high energy density, and high operating voltage. The traditional doctor-blade approach has been used over the years for producing batteries. Currently, research is being directed to additively manufacture Li-ion batteries via Drop-on-Demand Inkjet Printing with unique architectures towards further increasing energy density and satisfying special applications. The rheology and dispersion of particles in the slurry are critical parameters that affect the performance and printability of batteries in all production routes. In addition, the quality of lithium-ion batteries, including their electrochemical and durability performance, is significantly impacted by the consistency of the slurries used in their production. Thus, a physics-based model that accurately describes the consistency of these slurries is urgently needed to enable the precise optimization of battery manufacturing processes. This work is to develop a computational model to predict the rheology of electrode ink to be printed via Drop-on-demand inkjet printing. The rheology of electrode ink was modeled based on hydrodynamic and colloidal interactions, which include particle interaction, electrostatic forces, steric repulsive forces, and forces due to adsorbed polymer. MATLAB computer routines were used to solve the equations for forces acting in a different type of colloidal system and, ultimately, to predict the system's viscosity. The results from the computational model developed are validated by comparing them with published experimental results. The model agrees we (open full item for complete abstract)

Committee: Hong Huang Ph.D. (Committee Co-Chair); Ahsan Mian Ph.D. (Committee Co-Chair); Henry D. Young Ph.D. (Committee Member) Subjects: Chemical Engineering; Chemistry; Materials Science; Mechanical Engineering

Master of Science in Engineering, Youngstown State University, 2023, Department of Electrical and Computer Engineering

Lithium-ion batteries have revolutionized our everyday lives by laying the foundation for a wireless, interconnected and fossil-fuel-free society. Additionally, the demand for Li-ion batteries has seen a dramatic increase, as the automotive industry shifts up a gear in its transition to electric vehicles. To optimize the power and energy that can be delivered by a battery, it is necessary to predict the behavior of the cell under different loading conditions. However, electrochemical cells are complicated energy storage systems with nonlinear voltage dynamics. There is a need for accurate dynamic modeling of the battery system to predict behavior over time when discharging. The study conducted in this work develops an intuitive model for electrochemical cells based on a mechanical analogy. The mechanical analogy is based on a three degree of freedom spring-mass-damper system which is decomposed into modal coordinates that represent the overall discharge as well as the mass transport and the double layer effect of the electrochemical cell. The dynamic system is used to estimate the cells terminal voltage, open-circuit voltage and the mass transfer and boundary layer effects. The modal parameters are determined by minimizing the error between the experimental and simulated time responses. Also, these estimated parameters are coupled with a thermal model to predict the temperature profiles of the lithium-ion batteries. To capture the dynamic voltage and temperature responses, hybrid pulse power characterization (HPPC) tests are conducted with added thermocouples to measure temperature. The coupled model estimated the voltage and temperature responses at various discharge rates within 2.15% and 0.40% standard deviation of the error. Additionally, to validate the functionality of the developed dynamic battery model in a real system, a battery pack is constructed and integrated with a brushless DC motor (BLDC) and a load. Moreover, because of the unique pole ori (open full item for complete abstract)

Committee: Kyosung Choo PhD (Advisor); Frank Li PhD (Committee Member); Alexander Pesch PhD (Committee Member) Subjects: Electrical Engineering; Energy; Engineering; Mechanical Engineering

Doctor of Philosophy, Case Western Reserve University, 2023, EMC - Mechanical Engineering

This bench-scale experimental research studies the ignition mechanism by simulated firebrands in wildfire and thermal runaway of lithium-ion battery cells. The wildfire research investigates the effects of spatial distribution of multiple firebrands on ignition and burning characteristics of a combustible fuel substrate. The spatial distribution of firebrands is controlled by varying spacing between the firebrands. The research consists of two steps. In the first step, a square array of three-by-three birch wood cubes is ignited using hot electrical coils to generate flaming firebrands. These samples are positioned on suspension wires without a substrate to focus on burning and smoldering behavior of the firebrands only. The spacing is varied from 0 to 30 mm. It shows a non-monotonic dependency of burning intensity on firebrand spacing due to enhancement of flame heat intensity and decrease in air entrainment to flames when the spacing decreases. It is also found that the smoldering temperature and duration significantly increase when the firebrands are in proximity. The second step investigates the ignition of a fuel substrate caused by multiple firebrands. The firebrands are deposited on a 6.35 mm thick birch plywood under controlled wind conditions. An infrared camera monitors the temperature of firebrands and the plywood substrate. The experimental results exhibit that firebrands with 10 mm spacing result in the most severe fire damage of the plywood, whereas those with 20 mm spacing burn the largest area. A steady-state radiation model shows that the radiation heat flux from the firebrands is dominant during the heating process. Lastly, experimental method and apparatus are developed to collect time-resolved data on the gas compositions and fire characteristics during and post-thermal runaway of LIB cells. The cell at a desired state-of-charge (SOC) is forced into thermal runaway by an electrical heating tape at a constant heating rate. From the experiments (open full item for complete abstract)

Committee: Ya-Ting Liao (Committee Chair); Fumiaki Takahashi (Committee Member); Chris Yingchun Yuan (Committee Member); Gary Wnek (Committee Member) Subjects: Mechanical Engineering

Doctor of Philosophy, University of Akron, 2022, Polymer Engineering

To develop advanced sustainable technologies for the energy needs of society, solid-state lithium-ion batteries are considered safer and more reliable. In those aspects, solid polymer electrolytes have been considered as one of the promising candidates. The present dissertation focuses on the exploration of solid polymer electrolytes with high ionic conductivity, wider electrochemical stability window, enhanced stretchability, and ion storing capabilities of herein-developed polymer electrolyte membranes. Chapter III of the dissertation deals with elucidation on the effect of different plasticizers viz. succinonitrile (SCN), ethylene carbonate (EC), and polyethylene glycol dimethyl ether (PEGDME) on ionic conductivity, electrochemical stabilities, and stability of plasticized PEMs against the lithium metal anode. Succinonitrile plasticized PEMs demonstrated higher ionic conductivity (~ 10-3 S/cm) with higher electrochemical stability (~ 5 V). On the other hand, ethylene carbonate-based PEMs exhibited higher stability against lithium metal. Lastly, the addition of lithium bis(oxalate) borate (LiBOB) additive to PEMs which resulted in improvement of stability against the lithium metal is discussed. To improve the stretchability of the polymer electrolyte membranes (PEMs), PEG-b-PPG-b-PEG-DA block copolymer was synthesized by the esterification reaction. As a result of the high molecular weight of the block copolymer resulting in a loosely crosslinked copolymer network, the PEM consisting of PEG-b-PPG-b-PEG-DA/EC/LiTFSI exhibited increased stretchability (> 100 % elongation at break) along with ionic conductivity of superionic conductor level (~10-3 S/cm). Furthermore, thermal, and electrochemical stability of PEMs along with the satisfactory room temperature charge/discharge cycling performance of half-cells were discussed in detail in Chapter IV. The investigation of superionic, wider electrochemically stable, ion storing, supercapacitve nature of polyethylene g (open full item for complete abstract)

Committee: Thein Kyu (Advisor); Xiong Gong (Committee Chair); Jae-Won Choi (Committee Member); Steven Chuang (Committee Member); Ruel McKenzie (Committee Member) Subjects: Energy; Engineering; Materials Science; Polymer Chemistry; Polymers

Master of Science in Engineering, Youngstown State University, 2022, Department of Civil/Environmental and Chemical Engineering

Additive manufacturing (AM) commonly referred to as 3D printing is a method of manufacturing three-dimensional parts in a layer-by-layer fashion. Common materials used in this process are polymers, metals, and ceramics. Nowadays, AM is utilized for more than just traditional structures - it is used to fabricate and create nontraditional designs. Additive manufacturing is associated with various industrial manufacturing processes and innovations including maintenance, repairs, and product design. Among the different applications of this process, the production of 3D printed morphing systems and parts for batteries represents an attractive approach for yielding high-performance structures. Non-metallic morphing components are commonly constituted by shape memory polymers (SMPs), which are actuating materials that can respond to thermal, electrical, or chemical stimuli. Here, SMPs were constructed by incorporating two different blends of photopolymer resins in a Vat Photopolymerization process. The printed SMPs were subsequently electroplated with copper to yield a conductive morphing structure for applications such as sensors, actuating systems, and functional antennas. The present work investigated the adaptability and functionality of the copper-plated 3D printed parts as morphing antennas capable of providing a multi-radio frequency. Additionally, this research program investigated the production and performance of 3D printed LiFePO4 parts via Vat Photo Polymerization to be used as electrodes on additively manufactured energy storage devices. This effort represents a novel approach to further expanding the production of customized batteries.

Committee: Pedro Cortes PhD (Advisor); Vamsi Borra PhD (Committee Member); Frank Li PhD (Committee Member) Subjects: Aerospace Materials; Chemical Engineering; Materials Science; Polymers

Master of Science, The Ohio State University, 2022, Mechanical Engineering

The major shift in the mobility industry towards electric vehicles requires the development of safer energy storage systems (ESS). Li-ion ESS has been at the forefront of automotive, aerospace, and stationary ESS for power backup applications, albeit it suffers from thermal instability issues, which prompts investigation into the thermal behavior of these systems. Thermal modeling of Li-ion batteries is an essential practice to understand the mechanisms behind heat generation and distribution, and cognizance of the thermal behavior is crucial to developing safer Li-ion batteries and optimal thermal management solutions. However, one of the most significant challenges associated with developing thermal models is parameter identification due to the unique layered construction of a Li-ion cell. The simplest thermal model for a Li-ion battery can require the identification of ten or more unknown parameters. The accuracy of the model depends on the accuracy of the parameter identification process. Thermal models also require electrical models to predict heat generation in the cell, which requires a plethora of unknown parameters to be identified to simulate the electrical behavior of the cell. The overall accuracy of predicted temperature and thermal distribution is dependent on the accuracy of both the electrical and thermal models. The parameter identification for thermal modeling requires extensive experimentation, with its challenges, such as heat propagation to the experimental setup and power cables connecting the cell to the battery cycler. The goal of the research presented in this thesis is to develop an innovative experimental setup, test procedures, and calibration strategy for a lumped-parameter thermal model with the aim of accurately estimating the temperature of the cell and the cell tabs. The research aims at developing a test bench capable of minimizing the heat transfer from the cell to the power cables and the ambient. Two thermal exper (open full item for complete abstract)

Committee: Marcello Canova (Advisor); Kim Jung Hyun (Committee Member); Matilde D’Arpino (Advisor) Subjects: Mechanical Engineering