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.
Results
Showing 1 to 20 of 34 for “"ion conductivity"”.
-
Investigation into Lithium-Ion Conductivity and Redox Stability of Selenium-Doped Lithium Lanthanum Titanate
… lithium lanthanum titanate of composition Li₀.₃₃La₀.₅₆Ti₁₋ₓSeₓO3 (x = 0, 0.025, 0.050, 0.075) was attempted using a two-step conventional synthesis process to investigate the potential of the material as a solid-state electrolyte in lithium-ion batteries. Impedance spectroscopy data …
-
Towards more stable and ion-conductive organic electrolytes for rechargeable batteries
… fuels and significantly increase the utilization of renewable energy. Rechargeable batteries are important enablers of sustainable energy use, as they can be employed to store energy generated from renewable but intermittent source. Enhancing the functionality of battery electrolytes, such as …
-
Mechanisms of Enhancing Solid Polymer Electrolytes Using Nanofillers and Ionic Liquid for Applications in Flexible Lithium Ion Batteries
Polymer-based electrolytes have gained much attention in recent decades due to their many advantages including high thermal and chemical stability, and the consequent enhanced safety in lithium ion batteries. Also, thin-film manufacturability and mechanical strength make the polymer-based …
-
Monte Carlo simulation of ion transport of high strain ionomeric polymer transducers
Ionomeric polymer transducers exhibit electromechanical coupling capabilities. The transport of charge due to electric stimulus is the primary mechanism of actuation for a class of polymeric active materials known as ionomeric polymer transducers (IPTs). The research presented in this dissertation …
-
From Block Copolymers to Crosslinked Networks: Anionic Polymerization Affords Functional Macromolecules for Advanced Technologies
Ion-containing macromolecules continue to stimulate new opportunities for emerging electro-active applications ranging from high performance energy devices to water purification membranes. Progress in polymer synthesis and engineering now permit well-defined, ion-containing macromolecules with …
-
Influence of Electronic Structure and Lattice Dynamics on Oxygen Ion Transport in Solid-State Ionic Conductors
Solid-state oxygen ion conductors are crucial for electrochemical devices such as separation membranes, solid-oxide electrolyzers, fuel cells, and sensors, serving as a technological link between renewable energy generation and consumption. Currently, these conductors are limited by slow transport …
-
Rational design of proton exchange membranes: perfluoro polymers with sulfonic acid and heteropoly acid functionalities
… is dictated by our understanding of pure PFSA ionomer materials like Nafion®, which performs well at saturated conditions but fails at low relative humidity and high operating temperatures (80-120 C). The motivation of this study is driven by an industry need for a proton exchange membrane …
-
Poly(Ethylene Oxide)/Graphene Oxide Polymer Nanocomposite Electrolyte for Lithium Ion Batteries
… the safety problems associated with the traditional liquid electrolytes while offering mechanical stability and thin film manufacturability. The main issue with SPEs is the lower ionic conductivity at room temperature compared to that of liquid electrolytes. Nanosized ceramic powders are known …
-
Bridging Mesoscale Phenomena and Macroscopic Properties in Block Copolymers Containing Ionic Interactions and Hydrogen Bonding
Anionic polymerization and controlled radical polymerization enabled the synthesis of novel block copolymers with non-covalent interactions (electrostatic interaction and/or hydrogen bonding) to examine the relationships between mesoscale phenomenon and macroscopic physical properties. Non-covalent …
-
Multiscale Tortuous Diffusion in Anion- and Cation-Exchange Membranes: Exploration of Counterions, Water Content, and Polymer Functionality
… and morphology is critical for improving ion conductivity in polymer electrolyte membranes (PEMs). Herein, we present comprehensive water transport measurements comparing anion-exchange membranes (AEMs) based on ammonium-functionalized poly(phenylene oxide) and cation-exchange membranes …
-
Influence of lattice dynamics on the ionic conductivity and stability of solid-state lithium-ion conductors
… performance limit their use in many transportation and stationary applications. Lithium-ion batteries are one of the leading candidates for these large applications, however their current use of liquid electrolytes negatively effects their lifetime and safety. Furthermore, the liquid …
-
Synthetic and Post-Synthetic Methods towards Fine Tuning the Chemical and Physical Properties of Metal-Organic Frameworks
… on modulating redox activity, framework composition, and ionic conductivity. The first part of the work focuses on leveraging MOF-embedded polynuclear metal clusters for multi-electron redox chemistry. A square-planar tetramanganese cluster was shown to reversibly interconvert between molecular …
-
Data-driven understanding and forecasting of electrochemical systems
… industry has been underpinned by innovations in battery technology, and batteries are subject to more public interest now than ever before due to the uptake of electric vehicles and the demand for grid-scale batteries to stabilise an intermittent renewable energy supply. Most …
-
The Chemistry of Fullerenes, Polymers, and Host/Guest Interactions
The exploitation of the relationship between the chemical and physical properties of materials is the hallmark of advancing science throughout the world. The basic understanding of how and why molecules react and interact with each other in different environments allows for the discovery and …
-
FIRST-PRINCIPLES SIMULATIONS OF SOLID STATE BATTERY MATERIALS
In this work materials with possible applications in all solid state Li-ion batteries are explored using computational methods within the framework of density functional theory and kinetic Monte Carlo. The density functional theory simulations use fundamental quantum mechanics along with some …
-
Enhancing Interfaces in Solid Polymer Electrolyte-Based Flexible Lithium-Ion Batteries
… safer product from consumer, flexible Lithium-ion battery (LIB) has become a promising energy source to satisfy the requirements of wearable electronic devices. Biomaterials are safe, environmentally friendly and promising solutions to enhancing the properties of materials especially applicable …
-
Ionic conductivity transitions in antiperovskite ionic conductors
… cycling efficiency. However, the relatively low ionic conductivity of most solid state electrolytes has been considered as the major challenge. Antiperovskite(AP) electrolytes are recently developed solid state electrolyte with enhanced ionic conductivity. AP materials also provide an ideal …
-
Synthesis, Structure and Properties of Mixed Metal Oxides: From Pyrochlores to Fluorites
Introduction and Literature Review: Different families of oxide ion conductors and their applications are discussed. Experimental and Characterisation Methods: The synthetic methods and characterisation techniques used throughout this thesis are described. Synthesis, Structure and Transport …
-
Development of a combined multi-sensor/signal processing architecture for improved in-situ quantification of the charge balance of natural waters
This thesis details the design, implementation, and testing of a new electrochemical instrument for the in situ measurement of both major and environmentally relevant minor ions in fresh waters, namely Na+, K+, Ca2+, Mg2+, NH+4 , Cl-, NO-3 , and SO2-4 . The instrument is built on a hybrid …
-
Enhancing materials for fuel cells and organic solar cells through molecular design
… to enhance selected properties for applications in fuel cells and solar cells. In chapter 1, triptycene poly(aryl ethers) are synthesized and characterized for enhancing ion conductivity of ion exchange membranes in fuel cells. Triptycene motif is incorporated to increase charge density and …
Page 1 of 2