Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 137 for “"polymer electrolyte"”.
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Accelerating Polymer Electrolyte Discovery with Machine Learning
Solid polymer electrolytes (SPEs) have the potential to improve energy storage devices by enhancing safety and enabling higher energy densities. However, SPEs suffer from significantly lower ionic conductivity than liquid electrolytes, limiting their adoption in functional devices. To facilitate …
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Composite Gel Polymer Electrolyte for Lithium Ion Batteries
… to other alkali metals. In 1997, lithium polymer batteries with solid polymer/composite electrolyte were introduced where the safety drawbacks of the liquid electrolyte were eliminated but the ionic conductivity of the batteries was lower than that of a liquid. In this work, composite gel …
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Polymer electrolyte membranes for direct methanol fuel cells
… study is aimed at producing proton-conducting polymer electrolyte membranes (PEMs) for direct methanol fuel cells (DMFCs). In this thesis, relatively inexpensive monomers, 2-acrylamido-2-methyl propanesulfonic acid (AMPS) and 3-sulfopropyl methacrylate (SPM) in particular, were deployed as the …
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Condition monitoring of polymer electrolyte membrane fuel cells
… development, the Proton Exchange Membrane or Polymer Electrolyte Membrane (PEM) fuel cell has emerged as the technology of choice, and currently owns more than 80% of the commercial fuel cell market. This has spurred further research in the field to increase performance and life expectancy of …
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Microchannel flow fields for polymer electrolyte fuel cells
… Among the various types of fuel cells, the polymer electrolyte fuel cell (PEFC) is the leading candidate for portable, automotive and more recently stationary applications. One of the key challenges affecting both the performance and durability of low temperature PEFCs is water management. …
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Transients in Polymer Electrolyte Membrane (PEM) Fuel Cells
The need for energy efficient, clean and quiet, energy conversion devices for mobile and stationary applications has presented proton exchange membrane (PEM) fuel cells as a potential energy source. The use of PEM fuel cells for automotive and other transient applications, where there are rapid …
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Characterization of Electrically Controlled Gel Polymer Electrolyte Monopropellants
… limit their use. Monopropellants composed of gel polymer electrolytes present a unique opportunity which combines the safety features of gelled propellants as well as the ionic conductivity seen in ionic liquids, allowing them to decompose and ignite electrolytically. In this research, a family of …
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Comparative analysis of Polymer Electrolyte Membrane (PEM) fuel cells
… out as the preferable ionomers for making the Polymer Electrolyte Membrane Fuel Cells (PEMFC) membranes owing to their extensive intrinsic chemical stability and super sulfonic acid strength which is core to the PEMFC proton conductivity. This thesis presents a deeper analysis into these PFSA …
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Carbon nanotube supported electrocatalysts for polymer electrolyte membrane fuel cells
… aimed at a study of novel electrocatalysts for polymer electrolyte membrane (PEM) fuel cells. Carbon nanotubes have been studied as a new catalyst support. A sonochemical treatment method was applied for surface oxidation of multiwalled carbon nanotubes to achieve highly dispersed nanoparticles …
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Polymer Electrolyte Discovery via Rational Design and High Throughput Methods
… batteries will be enabled by advances in electrolytes which are the focus of this work. In this thesis, we focus on solid polymer electrolytes, which have the potential to enable more energy-dense batteries, and display improved safety compared to the highly flammable and toxic liquid …
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Mechanics and multi-physics deformation behavior of polymer electrolyte membranes
… and scalability. A central component is the polymer electrolyte membrane (PEM) which conducts protons from the fuel source (typically either hydrogen or methanol) at the anode to the cathode where it reacts with oxygen while preventing the transport of either electrons or the fuel itself. …
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Enhancing Interfaces in Solid Polymer Electrolyte-Based Flexible Lithium-Ion Batteries
… In this dissertation, a soy-based solid polymer electrolyte was introduced to improve the solid-state lithium-ion battery performance. The resultant composite electrolytes with 0.5wt% Tryptone Soy Broth (TSB) show about two orders of magnitude enhancement in ion conductivity. The …
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Self-assembly of conformal polymer electrolyte film for lithium ion microbatteries
… substrate lithium cobalt oxide (LCO) and the polymer separator poly(ethylene oxide). These predictions were first tested qualitatively using hexane and PTFE, which have well-established surface energies, and then by measuring the contact angles of PEO on LCO in hexane and hexadecane, chosen …
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Dynamic subdivided relative humidity model of a polymer electrolyte membrane fuel cell
… dynamic relative humidity model for a polymer electrolyte membrane (PEM) fuel cell stack is presented. This model is integrated with a first law based thermal model, which tracks energy flow within four defined control volumes in the fuel cell; the cathode channel, anode channel, …
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High throughput studies of polymer electrolyte for battery and fuel cell applications
… for the high-throughput characterisation of polymer electrolytes have<br/>been developed. Polymer electrolytes for use in lithium ion batteries have been<br/>prepared in a novel systematic manner that involves parallel preparation and subsequent<br/>high-throughput conductivity measurements …
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Water management strategies for polymer electrolyte fuel cells (PEFCs) employing microchannel flowfields
Polymer electrolyte fuel cells (PEFCs) represent a promising energy conversion technology for automotive and portable applications. In order to achieve the high power densities required for these applications, the fuel cell needs to be operated in the high current density region where the rate of …
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