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Analysis of Various Renewable Energy Systems as a Potential Replacement to Industrial Diesel Engine Systems [CLOSED DEFENSE]

Description

This thesis explores the investigation of the project “Designing for a Post-Diesel Engine World”, a collaborative experiment between organizations within Arizona State University and an undisclosed company. This investigation includes

This thesis explores the investigation of the project “Designing for a Post-Diesel Engine World”, a collaborative experiment between organizations within Arizona State University and an undisclosed company. This investigation includes the analysis of various renewable energy technologies and their potential to replace industrial diesel engines as used in the company’s business. In order to be competitive with diesel engines, the technology should match or exceed diesel in power output, have reduced environmental impact, and meet other criteria standards as determined by the company. The team defined the final selection criteria as: low environmental impact, high efficiency, high power, and high technology readiness level. I served as the lead Hydrogen Fuel Cell Researcher and originally hypothesized that PEM fuel cells would be the most viable solution. Results of the analysis led to PEM fuel cells and Li-ion batteries being top contenders, and the team developed a hybrid solution incorporating both of these technologies in a technical and strategic solution. The resulting solution design from this project has the potential to be modified and implemented in various industries and reduce overall anthropogenic emissions from industrial processes.

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  • 2021-05

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Safe Fire-resistant Electrolytes for Lithium-ion Batteries

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Lithium-ion batteries that employ an electrolyte consisting of LiFSI and TMP are shown to have better cycle performance than conventional carbonate electrolyte batteries at elevated temperatures. Additionally, an inorganic alumina

Lithium-ion batteries that employ an electrolyte consisting of LiFSI and TMP are shown to have better cycle performance than conventional carbonate electrolyte batteries at elevated temperatures. Additionally, an inorganic alumina or silica separator also improves cycling performance at high temperatures. Half-cells of Li metal and Li2TiO3 were constructed with LiFSI/TMP electrolyte and inorganic separators and cycled at increasing temperatures. Their cycle performance was compared to batteries with the same anode and cathode material that were prepared with conventional components. Half-cells using either the novel electrolyte or inorganic separators were able to continue cycling at temperatures up to 80 ℃, long after the conventionally prepared batteries had failed. A cell with a combination of the LiFSI/TMP electrolyte and silica separator still showed 75% capacity retention after 10 cycles at 85 ℃ as well.

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Date Created
  • 2019-05

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Creating a Lithium Ion Battery Separator for Stretchable Electronics

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This thesis research project seeks to provide an investigation to find the most appropriate organogel serving as a lithium ion battery separator that is compatible with stretchable electronics. Separators play

This thesis research project seeks to provide an investigation to find the most appropriate organogel serving as a lithium ion battery separator that is compatible with stretchable electronics. Separators play a key role in all batteries. Their main function is to keep the positive and negative electrodes apart to prevent electrical short circuits and at the same time allow rapid transport of ionic charge carriers that are needed to complete the circuit during the passage of current in an electrochemical cell [1].Li-ion batteries have become important in the field of electronic industry due to their advantages like compactness, lightweight, high operational voltage and providing highest energy density. Typical Li-ion battery has a cathode (LiCoO2, LiMnO2, LiFePO4 etc.), an anode (graphite, graphene, carbon nanotubes, carbon nanofibers, lithium titanium oxides etc.) and a separator [1]. The separator provides an electrical insulation between anode and cathode and allows ion transfer during operation. It also plays a significant role in determining battery performance. The performance of the Li-ion battery separator is determined by several factors such as permeability, porosity, electrolyte uptake capacity, mechanical, thermal and chemical stability. Several commercially available polymers have been used as separators and the most common polymers are poly(ethylene), poly(propylene), poly (ethylene oxide), poly(acrylonitrile), poly (methyl methacrylate) and poly (vinylidene fluoride) (PVDF) [3]. In this project, organogels were chosen because of their flexible, semi-permeable and reliable bendable characteristics which becomes useful in stretchable batteries. The first part is to use Polydimethylsiloxane (PDMS) which belongs to a group of polymeric organosilicon compounds that are commonly referred to as silicones, then mixed with hexane and sucrose solvents to make the required organogel. Different organogels from PDMS and Dragon skin in different amounts and conditions were created and tested to see what works best in stretchable lithium batteries, thus improving the battery’s efficiency and life cycle. Ion conductivity values were obtained after running the Electrochemical Impedance Spectroscopy Test. Graphs produced after this test proved that the most effective combination to use was at a porosity of 0.8, at a ratio of Sucrose: PDMS wt Ratio of 5: 0.764 respectively. The future endeavors of this project will involve working with reduced cell thickness so as to reduce the overall distance traveled by the ions, which also reduces the overall cost of making each separator.

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  • 2019-05

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Performance, modeling, and characteristics of LFP pack for HEV using FUDS (depleting) in hot and arid conditions

Description

There was a growing trend in the automotive market on the adoption of Hybrid Electric Vehicles (HEVs) for consumers to purchase. This was partially due to external pressures such

There was a growing trend in the automotive market on the adoption of Hybrid Electric Vehicles (HEVs) for consumers to purchase. This was partially due to external pressures such as the effects of global warming, cost of petroleum, governmental regulations, and popularity of the vehicle type. HEV technology relied on a variety of factors which included the powertrain (PT) of the system, external driving conditions, and the type of driving pattern being driven. The core foundation for HEVs depended heavily on the battery pack and chemistry being adopted for the vehicle performance and operations. This paper focused on the effects of hot and arid temperatures on the performance of LiFePO4 (LFP) battery packs and presented a possible modeling method for overall performance.

Lithium-ion battery (LIB) packs were subjected to room and high temperature settings while being cycled under a current profile created from a drive cycle. The Federal Urban Driving Schedule (FUDS) was selected and modified to simulate normal city driving situation using an electric only drive mode. Capacity and impedance fade of the LIB packs were monitored over the lifetime of the pack to determine the overall performance through the variables of energy and power fade. Regression analysis was done on the energy and power fade of the LIB pack to determine the duration life of LIB packs for HEV applications. This was done by comparing energy and power fade with the average lifetime mileage of a vehicle.

The collected capacity and impedance data was used to create an electrical equivalent model (EEM). The model was produced through the process of a modified Randles circuit and the creation of the inverse constant phase element (ICPE). Results indicated the model had a potential for high fidelity as long as a sufficient amount of data was gathered. X-ray powder diffraction (XRD) and a scanning electron microscope (SEM) was performed on a fresh and cycled LFP battery. SEM results suggested a dramatic growth on LFP crystals with a reduction in carbon coating after cycling. XRD effects showed a slight uniformed strain and decrease in size of LFP olivine crystals after cycling.

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Date Created
  • 2016

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Post-combustion electrochemical capture and release of CO₂ and deformation and bulk stress evolution in LiMn₂O₄ intercalation compounds

Description

This investigation is divided into two portions linked together by the momentous reaches of electrochemistry science, principles influencing everyday phenomena as well as innovative research in the field of energy

This investigation is divided into two portions linked together by the momentous reaches of electrochemistry science, principles influencing everyday phenomena as well as innovative research in the field of energy transformation. The first portion explores the strategies for flue gas carbon dioxide capture and release using electrochemical means. The main focus is in the role thiolates play as reversible strong nucleophiles with the ability to capture CO2 and form thiocarbonates. Carbon dioxide in this form is transported and separated from thiocarbonate through electrochemical oxidation to complete the release portion of this catch-and-release approach. Two testing design systems play a fundamental role in achieving an efficient CO2 catch and release process and were purposely build and adapted for this work. A maximum faradaic efficiency of seventeen percent was attained in the first membrane tests whose analysis is presented in this work. An efficiency close to thirty percent was attained with the membrane cell in recent experiments but have not been included in this manuscript.

The second portion of this manuscript studies bulk stress evolution resulting from insertion/extraction of lithium in/from a lithium manganese oxide spinel cathode structure. A cantilever-based testing system uses a sophisticated, high resolution capacitive technique capable of measuring beam deflections of the cathode in the subnanometer scale. Tensile stresses of up to 1.2 MPa are reported during delithiation along with compressive stresses of 1.0 MPa during lithiation. An analysis of irreversible charge loss is attributed to surface passivation phenomena with its associated stresses of formation following patterns of tensile stress evolution.

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Date Created
  • 2016