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ESTIMATION OF THERMAL STATE OF CHARGE FOR PCC BASED LITHIUM-ION BATTERY PACKS
Title
ESTIMATION OF THERMAL STATE OF CHARGE FOR PCC BASED LITHIUM-ION BATTERY PACKS
Creator
Salameh, Mohamad
Date
2016, 2016-07
Description
With continuing efforts to improve energy and power density of Li-ion batteries, heat generation and thermal safety remain critical barriers...
Show moreWith continuing efforts to improve energy and power density of Li-ion batteries, heat generation and thermal safety remain critical barriers to commercial success. Energy conversion in a battery is an exothermic process. Whenever the temperature of lithium-ion batteries increases, there can be direct consequences-reduced calendar and cycle life and higher risk of a battery re or explosion. Conventional approaches to prevent overheating use active thermal management systems, such as air conditioning or liquid cooling. However, these systems can be costly, bulky, and consume energy during operation. In addition they o er no overheat protection while the application or the vehicle is powered down. Phase change material composites (PCC) can be employed to rapidly absorb heat from the battery and distribute it, thereby enabling lightweight and compact packs with extended cycle-life and safety. This thesis proposes an online temperature estimation technique for a novel intelligent battery thermal management to actively monitor thermal mass of the phase change material. Such a system will not only enable avoidance of thermal issues, but will extend life of the battery pack by optimally selecting the operating point of the Energy Storage System. It can also be used to predict when active cooling should be employed just before the battery exits the phase change temperature plateau, to ensure latent heat absorption is spread across the entire drive cycle.
M.S. in Electrical Engineering, July 2016
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Design and Synthesis of New Sulfur Cathodes Containing Polysulfide Adsorbing Materials
Title
Design and Synthesis of New Sulfur Cathodes Containing Polysulfide Adsorbing Materials
Creator
Suzanowicz, Artur M
Date
2023
Description
Lithium-sulfur battery (LSB) technology has tremendous prospects to substitute lithium-ion battery (LIB) technology due to its high...
Show moreLithium-sulfur battery (LSB) technology has tremendous prospects to substitute lithium-ion battery (LIB) technology due to its high theoretical specific capacity and energy density. However, escaping polysulfide intermediates (produced during the redox reaction process) from the cathode structure is the primary reason for rapid capacity fading. Suppressing the polysulfide shuttle (PSS) is a viable solution for this technology to move closer to commercialization and supersede the established LIB technology. In this dissertation, I have analyzed the challenges faced by LSBs and selected methods and materials to address these problems. I have concluded that in order to further pioneer LSBs, it is necessary to address these essential features of the sulfur cathode: superior electrical conductivity to ensure faster redox reaction kinetics and high discharge capacity, high pore volume of the cathode host to maximize sulfur loading/utilization, and polar polysulfide-resistive materials to anchor and suppress the migration of lithium polysulfides.Furthermore, a versatile, low-cost, and practical scalable synthesis method is essential for translating bench-level development to large-scale production. This dissertation covers designing and synthesizing new scalable cathode structures for lithium-sulfur batteries that are inexpensive and highly functional. The rationally chosen cathode components accommodate sulfur, suppress the migration of polysulfide intermediates via chemical interactions, enhance redox kinetics, and provide electrical conductivity to sulfur, rendering excellent electrochemical performance in terms of high initial specific capacity and good long-term cycling performance. TiO2, Ni12P5, and g-C3N4 as polysulfide adsorbing materials (PAMs) have been fully studied in this thesis along with three distinct types of host structures for lithium-sulfur batteries: Polymer, Carbon Cloth, and Reduced Graphene Oxide. I have created adaptable bulk synthesis techniques that are inexpensive, easily scalable, and suitable for bench-level research as well as large-scale manufacturing. The exceptional performance and scalability of these materials make my cathodes attractive options for the commercialization of lithium-sulfur batteries.
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