Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Asymmetric Pathways In The Electrochemical Conversion Reaction Of Nio As Battery Electrode With High Storage Capacity
Download Asymmetric Pathways In The Electrochemical Conversion Reaction Of Nio As Battery Electrode With High Storage Capacity full books in PDF, epub, and Kindle. Read online Asymmetric Pathways In The Electrochemical Conversion Reaction Of Nio As Battery Electrode With High Storage Capacity ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Asymmetric Pathways in the Electrochemical Conversion Reaction of NiO as Battery Electrode with High Storage Capacity by :
Download or read book Asymmetric Pathways in the Electrochemical Conversion Reaction of NiO as Battery Electrode with High Storage Capacity written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrochemical conversion reactions of transition metal compounds create opportunities for large energy storage capabilities exceeding modern Li-ion batteries. However, for practical electrodes to be envisaged, a detailed understanding of their mechanisms is needed, especially vis-à-vis the voltage hysteresis observed between reduction and oxidation. Here, we present such insight at scales from local atomic arrangements to whole electrodes. NiO was chosen as a simple model system. The most important finding is that the voltage hysteresis has its origin in the differing chemical pathways during reduction and oxidation. This asymmetry is enabled by the presence of small metallic clusters and, thus, is likely to apply to other transition metal oxide systems. Lastly, the presence of nanoparticles also influences the electrochemical activity of the electrolyte and its degradation products and can create differences in transport properties within an electrode, resulting in localized reactions around converted domains that lead to compositional inhomogeneities at the microscale.
Book Synopsis Transition Metal Oxides for Electrochemical Energy Storage by : Jagjit Nanda
Download or read book Transition Metal Oxides for Electrochemical Energy Storage written by Jagjit Nanda and published by John Wiley & Sons. This book was released on 2022-03-30 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transition Metal Oxides for Electrochemical Energy Storage Explore this authoritative handbook on transition metal oxides for energy storage Metal oxides have become one of the most important classes of materials in energy storage and conversion. They continue to have tremendous potential for research into new materials and devices in a wide variety of fields. Transition Metal Oxides for Electrochemical Energy Storage delivers an insightful, concise, and focused exploration of the science and applications of metal oxides in intercalation-based batteries, solid electrolytes for ionic conduction, pseudocapacitive charge storage, transport and 3D architectures and interfacial phenomena and defects. The book serves as a one-stop reference for materials researchers seeking foundational and applied knowledge of the titled material classes. Transition Metal Oxides offers readers in-depth information covering electrochemistry, morphology, and both in situ and in operando characterization. It also provides novel approaches to transition metal oxide-enabled energy storage, like interface engineering and three-dimensional nanoarchitectures. Readers will also benefit from the inclusion of: A thorough introduction to the landscape and solid-state chemistry of transition metal oxides for energy storage An exploration of electrochemical energy storage mechanisms in transition metal oxides, including intercalation, pseudocapacitance, and conversion Practical discussions of the electrochemistry of transition metal oxides, including oxide/electrolyte interfaces and energy storage in aqueous electrolytes An examination of the characterization of transition metal oxides for energy storage Perfect for materials scientists, electrochemists, inorganic chemists, and applied physicists, Transition Metal Oxides for Electrochemical Energy Storage will also earn a place in the libraries of engineers in power technology and professions working in the electrotechnical industry seeking a one-stop reference on transition metal oxides for energy storage.
Book Synopsis Nanostructured Materials for Energy Storage by : Kalim Deshmukh
Download or read book Nanostructured Materials for Energy Storage written by Kalim Deshmukh and published by John Wiley & Sons. This book was released on 2024-08-14 with total page 1981 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive reference work for researchers and engineers working with advanced and emerging nanostructured battery and supercapacitor materials Lithium-ion batteries and supercapacitors play a vital role in the paradigm shift towards sustainable energy technology. This book reviews how and why different nanostructured materials improve the performance and stability of batteries and capacitors. Sample materials covered throughout the work include: Graphene, carbon nanotubes, and carbon nanofibers MXenes, hexagonal boron nitride, and transition metal dichalcogenides Transition metal oxides, metal-organic frameworks, and lithium titanates Gel polymer electrolytes, hydrogels, and conducting polymer nanocomposites For materials scientists, electrochemists, and solid state chemists, this book is an essential reference to understand the lithium-ion battery and supercapacitor applications of nanostructured materials that are most widely used for developing low-cost, rapid, and highly efficient energy storage systems.
Book Synopsis Transitions from Near-surface to Interior Redox Upon Lithiation in Conversion Electrode Materials by :
Download or read book Transitions from Near-surface to Interior Redox Upon Lithiation in Conversion Electrode Materials written by and published by . This book was released on 2015 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanoparticle electrodes in lithium-ion batteries have both near-surface and interior contributions to their redox capacity, each with distinct rate capabilities. Using combined electron microscopy, synchrotron X-ray methods and ab initio calculations, we have investigated the lithiation pathways that occur in NiO electrodes. We find that the near-surface electroactive (Ni22!i0) sites saturated very quickly, and then encounter unexpected difficulty in propagating the phase transition into the electrode (referred to as a "shrinking-core" mode). However, the interior capacity for Ni22!i0 can be accessed efficiently following the nucleation of lithiation "fingers" which propagate into the sample bulk, but only after a certain incubation time. Our microstructural observations of the transition from a slow shrinking-core mode to a faster lithiation finger mode corroborate with synchrotron characterization of large-format batteries, and can be rationalized by stress effects on transport at high-rate discharge. The finite incubation time of the lithiation fingers sets the intrinsic limitation for the rate capability (and thus the power) of NiO for electrochemical energy storage devices. The present work unravels the link between the nanoscale reaction pathways and the C-rate-dependent capacity loss, and provides guidance for the further design of battery materials that favors high C-rate charging.
Book Synopsis Electrochemical and Thermodynamic Study of Electrode Materials on Li-ion Batteries and Aqueous Energy Storage and Conversion Applications by : Joon Kyo Seo
Download or read book Electrochemical and Thermodynamic Study of Electrode Materials on Li-ion Batteries and Aqueous Energy Storage and Conversion Applications written by Joon Kyo Seo and published by . This book was released on 2017 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: The energy storage and conversion is one of the key issues for human beings to live sustainably on earth since our living environment has been deteriorating with the development of industrialization. We can alleviate the waste of energy consumption and corresponding environmental pollutions by storing and converting energy efficiently. The electrochemical cells are drawing considerable attention recently as a promising solution. In this thesis, electrode materials for Li-ion batteries and aqueous electrochemical cells are studied, focusing on the electrochemical and thermodynamic aspects. First, transition metal difluorides, MF2 (M = Fe,Ni, and Cu) are explored. It is found that the conversion-reaction voltage is associated with the size of the converted metal nanoparticles. The surface energy of metal nanoparticles reduces the reaction energy, which decreases the conversion-reaction voltage. In addition, CuF2 electrodes are rechargeable when it is coated with NiO. NiO alleviates Cu dissolution into an electrolyte and enhances the cyclability of CuF2. Second, Zn/[beta]-MnO2 alkaline battery is studied as a promising rechargeable energy storage of high capacity. The nano-sized [beta]-MnO2 cathode in the alkaline electrolyte of LiOH and KOH exhibit the average discharge capacity of 280 mAh g-1 over the first 100 cycles. It is found that the [beta]-MnO2 transforms through proton intercalation and conversion reactions. The capacity is improved further with an addition of 4% mole fraction Bi2O3 in the nanosized [beta]-MnO2. Third, density functional theory (DFT) calculations are conducted for Li4Ti5O12 (LTO), its Gadolinium (Gd)-doped, and lithiated phases. The density of states (DOS) of LTO exhibits the property of an electrical insulator, however Gd-doped LTO is an electrical conductor which enhances the electrochemical performance. In addition, the formation energy of lithiated LTO phases is calculated to understand the reaction mechanism of LTO upon lithiation. The calculated results show that the lithiation proceeds by the two-phase reaction and there is no intermediate phase between two end phases: Li4Ti5O12 and Li7Ti5O12. Lastly, oxygen evolution reaction (OER) on YBaCo4O7 (110) is investigated by DFT calculations. The results indicate that OER can be easily activated by YBaCo4O7 (110) due to its low overpotential. The free energy diagram exhibits the oxidation from O* to OOH*, which is the rate-determining step.
Book Synopsis Influence of Morphology and Environment on the Electrochemical Reactivity of NiO by : Neil S. Spinner
Download or read book Influence of Morphology and Environment on the Electrochemical Reactivity of NiO written by Neil S. Spinner and published by . This book was released on 2013 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Multiscale Chemo-mechanical Mechanics of High-capacity Anode Materials in Lithium-ion Nano-batteries by : Hui Yang
Download or read book Multiscale Chemo-mechanical Mechanics of High-capacity Anode Materials in Lithium-ion Nano-batteries written by Hui Yang and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Rechargeable lithium-ion batteries (LIBs), which are the most prevailing and promising electrochemical energy storage and conversion devices due to their high energy density and design flexibility, are widely used in portable electronics and electric vehicles. Currently commercialized LIBs adopt graphite as anode for its long cycle life, abundant material supply, and relatively low cost. However, graphite suffers low specific charge capacity (372 mAhg-1), which is obviously insufficient for powering new generation electronic devices. Thus, considerable efforts are being undertaking to develop alternative anode materials with low cost, high capacity, and long cycle life. A variety of high capacity anode materials have been identified, and silicon (Si) stands as the leading candidate and has attracted much attention for its highest theoretical capacity (4200 mAhg-1). Nevertheless, inherent to the high-capacity electrodes, lithium (Li) insertion-extraction cycling induces huge volumetric expansion and stress inside the electrodes, leading to fracture, pulverization, electrical disconnectivity, and ultimately huge capacity loss. Therefore, a fundamental understanding of the degradation mechanisms in the high-capacity anodes during lithiation-delithiation cycling is crucial for the rational design of next-generation failure-resistant electrodes.In this thesis, a finite-strain chemo-mechanical model is formulated to study the lithiation-induced phase transformation, morphological evolution, stress generation and fracture in high capacity anode materials such as Si and germanium (Ge). The model couples Li reaction-diffusion with large elasto-plastic deformation in a bidirectional manner: insertion of the Li into electrode generates localized stress, which in turn mediates electrochemical insertion rates. Several key features observed from recent transmission electron microscopy (TEM) studies are incorporated into the modeling framework, including the sharp interface between the lithiated amorphous shell and unlithiated crystalline core, crystallographic orientation-dependent electrochemical reaction rate, and large-strain plasticity. The simulation results demonstrate that the model faithfully predicts the anisotropic swelling of lithiated crystalline silicon nanowires (c-SiNWs) observed from previous experimental studies. Stress analysis reveals that the SiNWs are prone to surface fracture at the angular sites where two adjacent facets intersect, consistent with previous experimental observations. In addition, Li insertion can induce high hydrostatic pressure at and closely behind the reaction front, which can lead to the lithiation retardation observed by TEM studies.For a comparative study, the highly reversible expansion and contraction of crystalline germanium nanoparticles (c-GeNPs) under lithiation-delithiation cycling are reported. During multiple cycles to the full capacity, the GeNPs remain robust without any visible cracking despite ~260% volume changes, in contrast to the size dependent fracture of crystalline silicon nanoparticles (c-SiNPs) upon the first lithiation. The comparative study of c-SiNPs, c-GeNPs, and amorphous SiNPs (a-SiNPs) through in-situ TEM and chemo-mechanical modeling suggest that the tough behavior of c-GeNPs and a-SiNPs can be attributed to the weak lithiation anisotropy at the reaction front. In the absence of lithiation anisotropy, the c-GeNPs and a-SiNPs experience uniform hoop tension in the surface layer without the localized high stress and therefore remain robust throughout multicycling. In addition, the two-step lithiation in a-SiNPs can further alleviate the abruptness of the interface and hence the incompatible stress at the interface, leading to an even tougher behavior of a-SiNPs. Therefore, eliminating the lithiation anisotropy presents a novel pathway to mitigate the mechanical degradation in high-capacity electrode materials. In addition to the study of the retardation effect caused by lithiation self-generated internal stress, the influence of the external bending on the lithiation kinetics and deformation morphologies in germanium nanowires (GeNWs) is also investigated. Contrary to the symmetric core-shell lithiation in free-standing GeNWs, bending a GeNW during lithiation breaks the lithiation symmetry, speeding up lithaition at the tensile side while slowing down at the compressive side of the GeNWs. The chemo-mechanical modeling further corroborates the experimental observations and suggests the stress dependence of both Li diffusion and interfacial reaction rate during lithiation. The finding that external load can mediate lithiation kinetics opens new pathways to improve the performance of electrode materials by tailoring lithiation rate via strain engineering. Furthermore, in the light of bending-induced symmetry breaking of lithiation, the mechanically controlled flux of the secondary species (i.e., Li) features a novel energy harvesting mechanism through mechanical stress.Besides the continuum level chemo-mechanical modelings, molecular dynamics simulations with the ReaxFF reactive force field are also conducted to investigate the fracture mechanisms of lithiated graphene. The simulation results reveal that Li diffusion toward the crack tip is both energetically and kinetically favored owing to the crack-tip stress gradient. The stress-driven Li diffusion results in Li aggregation around the crack tip, chemically weakening the crack-tip bond and at the same time causing stress relaxation. As a dominant factor in lithiated graphene, the chemical weakening effect manifests a self-weakening mechanism that causes the fracture of the graphene. Moreover, lithiation-induced fracture mechanisms of defective single-walled carbon nanotubes (SWCNTs) are elucidated by molecular dynamics simulations. The variation of defect size and Li concentration sets two distinct fracture modes of the SWCNTs upon uniaxial stretch: abrupt and retarded fracture. Abrupt fracture either involves spontaneous Li weakening of the propagating crack tip or is absent of Li participation, while retarded fracture features a "wait-and-go" crack extension process in which the crack tip periodically arrests and waits to be weakened by diffusing Li before extension resumes. The failure analysis of the defective CNTs upon lithiation, together with the cracked graphene, provides fundamental guidance to the lifetime extension of high capacity anode materials.
Book Synopsis Investigations of Oxygen Reduction Reactions for Electrochemical Energy Storage and Conversion by : Iromie A. Gunasekara
Download or read book Investigations of Oxygen Reduction Reactions for Electrochemical Energy Storage and Conversion written by Iromie A. Gunasekara and published by . This book was released on 2015 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: High energy density portable power solutions have been of utmost importance for the advancement of modern day necessities such as data and voice communication, vehicular transportation, distributed power generation and storage of energy produced by sustainable power sources. Progress made in fuel cell and lithium-ion battery technologies over the past decade have opened opportunities to power electric and hybrid electric vehicles for long distance transportation. Alkaline membrane fuel cells (AEMFCs) are the new alternatives to proton exchange membrane fuel cells (PEMFCs), which require generous amounts of noble metal-based catalysts on their electrodes. Facile electrode kinetics on non-precious group metal catalysts in alkaline environments is the key factor which has promoted AEMFCs over PEMFCs. While the research on AEMFCs is vastly expanding, high energy density batteries are praiseworthy considering the high cost of hydrogen fuel. The state-of-the-art Li-ion batteries cannot reach the desirable capacity density to power electric vehicles capable of >300 miles on a single charge whereas Li-O2 batteries with a theoretical capacity more than ten times larger than that of Li-ion have become very promising for this application. Chapter 1 of this thesis provides a discussion of the background behind the fuel cell and battery technologies beyond Li-ion along with the electrochemical and analytical techniques employed throughout this investigation. The major deterrent to AEMFC technology is its performance decrease by means of carbonate exchange of the membrane when exposed to carbon dioxide. The second Chapter deals with a quantitative determination of the influence of carbonate ions in the alkaline membrane on interfacial electrode reactions and reactant transport through the membrane. A Pt microelectrode investigation conducted on a commercial anion exchange membrane (AEM) (Tokuyama, A201) showed rather close kinetics for oxygen reduction reaction (ORR) with and without carbonate exchange as well as with a perfluorinated proton exchange membrane analog such as Nafion®. Resolution of the mass transport into constituent components (diffusion coefficient and solubility) showed that the oxygen diffusion coefficient in the AEM exchanged with carbonate ions (CO32−) is lowered while the solubility remained unaffected. These results show remarkable agreement with polarization corrected fuel cell data, thus enabling a method to better resolve interfacial performance of an AEM fuel cell. We have also investigated the kinetics of hydrogen oxidation reaction (HOR) and methanol oxidation reaction (MOR) at the Tokuyama (A201/A901) anion exchange membrane /Pt microelectrode interfaces using solid state electrochemical cells. Diffusion of hydrogen molecules through the membrane was not influenced by the carbonate ions due to the smaller size of the gaseous molecule. However, hydrogen concentration in the anion exchange membrane is low in the presence of carbonate ions. Methanol diffusion is facilitated in the anion exchange polymer electrolyte due to its high water content. A change of the diffusion path length in carbonate polymer electrolytes caused methanol permeability to drop significantly. The kinetic parameters obtained for the AEM in the carbonate form suggests that both hydrogen and methanol oxidation reactions proceed through the carbonate pathway. Therefore, the kinetic parameters obtained are significantly lower than what were observed at the AEM in the hydroxide form. In the third Chapter I demonstrate that a microelectrode can be used as a diagnostic tool to determine O2 transport properties and redox kinetics in dimethyl sulfoxide (DMSO)–based electrolytes for non-aqueous Li-air batteries, and to elucidate the influence of ion-conducting salts on the O2 reduction reaction mechanism. Oxygen reduction/evolution reactions on a carbon microelectrode have been studied in dimethyl sulfoxide-based electrolytes containing Li+ and tetrabutylammonium ((C4H9)4N+) ions. Analysis of chronoamperometric current-time transients of the oxygen reduction reactions in the series of tetrabutylammmonium (TBA) salt-containing electrolytes of TBAPF6, TBAClO4, TBACF3SO3, or TBAN(CF3SO2)2 in DMSO revealed that the anion of the salt exerts little influence on O2 transport. Whereas steady-state ORR currents (with sigmoidal-shaped current-potential curves) were observed in TBA-based electrolytes, peak-shaped current-voltage profiles were seen in the electrolytes containing their Li salt counterparts. The latter response results from the combined effects of the electrostatic repulsion of the superoxide (O2−-) intermediate as it is reduced further to peroxide (O22−) low potentials and the formation of passivation films of the O2 reduction products at the electrode. Raman spectroscopic data confirmed the formation of non-conducting Li2O2 and Li2O on the electrode surface at different reduction potentials in Li salt solutions. Out of the four lithium salt-containing electrolytes studied, namely LiPF6, LiClO4, LiCF3SO3, or LiN(CF3SO2)2 in DMSO, the LiCF3SO3/DMSO solution revealed the most favorable ORR kinetics and the least passivation of the electrode by ORR products. The influence of lithium salts on O2 reduction reactions (ORR) in 1, 2-dimethoxyethane (DME) and tetraethylene glycol dimethyl ether (TEGDME) has been investigated in Chapter 4. Microelectrode studies in a series of tetrabutylammonium salt (TBA salt)/DME-based electrolytes showed that O2 solubility and diffusion coefficient are not significantly affected by the electrolyte anion. The ORR voltammograms on microelectrodes in these electrolytes exhibited steady-state limiting current behavior. In contrast, peak-shaped voltammograms were observed in Li+-conducting electrolytes suggesting a reduction of the effective electrode area by passivating ORR products as well as migration-diffusion control of the reactants at the microelectrode as observed in DMSO-based electrolytes. FT-IR spectra have revealed that Li+ ions are solvated to form solvent separated ion pairs of the type Li+(DME)nPF6− and Li+(TEGDME)PF6− in LiPF6-based electrolytes. On the other hand, the contact ion pairs (DME)mLi+(CF3SO3−) and (TEGDME)Li+(CF3SO3−) appear to form in LiSO3CF3-ontaining electrolytes. In the LiSO3CF3-based electrolytes, the initial ORR product, superoxide (O2−), is stabilized in solution by forming [(DME)m−1(O2−)]Li+(CF3SO3−) and [(TEGDME)(O2−)]Li+(CF3SO3−) complexes. These soluble superoxide complexes are able to diffuse away from the electrode surface reaction sites to the bulk electrolyte in the electrode pores where they decompose to form Li2O2. This explains the higher capacity obtained in Li/O2 cells utilizing LiCF3SO3/TEGDME electrolytes. In Chapter 5 the synthesis of iron(II) phathlaocyanine (FePC)-based catalysts is presented. FePC embedded in a carbon support was heat-treated at a series of temperatures (300oC, 600oC and 800oC) and characterized by means of several spectroscopic and electrochemical techniques. Catalytic oxygen reduction recorded in the low Donor Number acetonitrile (MeCN)-based electrolytes have shown that the oxygen reduction reaction (ORR) mechanism is modified at the catalyst surface. Redox electrochemistry of FePC recorded in argon saturated electrolytes has confirmed that the iron is in the Fe(I) state at the O2 reduction potential in these electrolytes which is capable of stabilizing the superoxide leading to an inner[nil]Helmholtz plane electron transfer reaction. In high Donor Number DMSO[nil]based electrolytes the ORR was not influenced by the catalyst and this has been attributed to the oxidation state of iron being Fe(II) at the superoxide forming potential. The superoxide formed in such conditions are stabilized by the DMSO solvated softer Lewis acid Li+ as the Li+(DMSO)n-O2− ion pair in solution. The ORR reaction in this electrolyte proceeds through an outer Helmholtz plane electron transfer process despite the presence of the FePC catalyst in the electrode. Catalyzed carbon electrodes treated at 300 and 600oC were successfully employed in the low Donor Number tetra ethylene glycol dimethyl ether (TEGDME)[nil]based electrolyte-containing Li-O2
Book Synopsis Electrode Materials for Energy Storage and Conversion by : Mesfin A. Kebede
Download or read book Electrode Materials for Energy Storage and Conversion written by Mesfin A. Kebede and published by CRC Press. This book was released on 2021-11-17 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive overview of the latest developments and materials used in electrochemical energy storage and conversion devices, including lithium-ion batteries, sodium-ion batteries, zinc-ion batteries, supercapacitors and conversion materials for solar and fuel cells. Chapters introduce the technologies behind each material, in addition to the fundamental principles of the devices, and their wider impact and contribution to the field. This book will be an ideal reference for researchers and individuals working in industries based on energy storage and conversion technologies across physics, chemistry and engineering. FEATURES Edited by established authorities, with chapter contributions from subject-area specialists Provides a comprehensive review of the field Up to date with the latest developments and research Editors Dr. Mesfin A. Kebede obtained his PhD in Metallurgical Engineering from Inha University, South Korea. He is now a principal research scientist at Energy Centre of Council for Scientific and Industrial Research (CSIR), South Africa. He was previously an assistant professor in the Department of Applied Physics and Materials Science at Hawassa University, Ethiopia. His extensive research experience covers the use of electrode materials for energy storage and energy conversion. Prof. Fabian I. Ezema is a professor at the University of Nigeria, Nsukka. He obtained his PhD in Physics and Astronomy from University of Nigeria, Nsukka. His research focuses on several areas of materials science with an emphasis on energy applications, specifically electrode materials for energy conversion and storage.
Book Synopsis Nanoscale Electrode Architectures for Electrochemical Energy Conversion and Storage by : Venkat Kalyan Vendra
Download or read book Nanoscale Electrode Architectures for Electrochemical Energy Conversion and Storage written by Venkat Kalyan Vendra and published by . This book was released on 2015 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanoscale electrode architectures are at the heart of photoelectrochemical devices converting sunlight into electricity and electrochemical devices that store energy. Advanced nanomaterials encompassing 1-D architectures such as single crystalline metal oxide nanowires, 2-D architectures such graphene nanosheets and nanoparticle-nanowire hybrids have garnered significant interest as promising materials for fabricating thicker electrodes due their unique electronic, phase transformation and strain relaxation properties. However, electrode architectures incorporating these advanced nanomaterials will have a transformational impact on large scale electrode manufacturing only if the challenges associated with the electrode durability are addressed. At a fundamental level, the reactions happening at the electrode-electrolyte interface need to be studied in detail in order to address the durability issues. The overall objective of this dissertation is to develop electrode architectures with high durability for solar energy conversion and storage by employing engineered materials with excellent charge transport and charge separation properties. Specifically, electrodes architectures that enable high durability for dye-sensitized solar cells using alternate redox electrolytes and moisture resistant perovskite solar cells, and lithium manganese oxide cathodes for Li ion batteries have been developed. In dye-sensitized solar cells, there is immense interest in replacing the conventionally used, highly corrosive iodide redox electrolyte with non-corrosive one-electron redox electrolytes that can result in higher cell stability. However, a major shortcoming of one-electron redox electrolytes is their fast electron recombination kinetics when compared to the iodide electrolyte. To address this issue, tin oxide nanowires are investigated as an alternative for conventionally used titania nanoparticles in dye sensitized solar cells. Further, hybrid architectures comprising of titania nanoparticles-tin oxide nanowires are found to be effective in overcoming the limitations of low dye adsorption and low open-circuit voltage, posed by nanowire electrodes. To gain deeper insight into the electron transport and recombination kinetics of different electrode architectures in conjunction with different redox electrolytes, fundamental studies are performed using electrochemical techniques. In addition, the application of alternate absorbers in solar cells is crucial in attempting to address the challenges posed by the state-of-the art dyes. Of particular interest are the metal-organic hybrid perovskites that have high absorption coefficient and excellent hole conductivity. Though perovskites have resulted in breakthrough performance for solar cells, degradation of perovskites due to moisture is a huge road block limiting the progress of perovskite solar cells. The moisture instability of perovskites is addressed using a novel concept of a thick, highly conductive graphene-conductive polymer composite for the encapsulation of the perovskite nanocrystals. Electrode architectures for highly durable cathode materials for application in Li ion batteries have also been developed in this dissertation. Most of the widely investigated anodes have higher capacity when compared to the cathodes. In order to balance the capacity of both electrodes, the cathodes need to be made thicker. Nanoparticle electrodes are not ideal for making thicker electrodes as the poor charge transport characteristics result in increased series in thicker nanoparticle electrodes and subsequently lead to a loss in cell voltage. Further, electrode materials for Li ion batteries require the structural integrity of the material to be maintained through several charge-discharge cycles. Layered transition metal oxides and their alloys have been widely investigated as cathode materials in Li ion batteries due to their potential for achieving high capacity. Poor surface stability and increased strain on the lattice associated with the phase transformation occurring during battery charging and discharging are the major reasons for poor cycle stability of the commonly used layered transition metal cathodes. In this work, single crystalline nanowires of a layered transition metal oxide, namely Li2MnO3 are investigated as cathode materials in Li ion batteries in order to address the limitations posed by layered transition metal cathodes. A detailed investigation of the cycled electrodes showed that single crystalline nanowires allow for the facile phase transformation of the Li2MnO3 to a zero strain spinel phase of LiMn2O4. The phase transformation on single crystalline Li2MnO3 NWs result in the formation of conformal and thicker (20-30 nm) spinel LiMn2O4 shell that is very effective in improving the surface stability of the electrodes and hence prevents the capacity loss during cycling.
Book Synopsis High Energy Density Lithium Batteries by : Katerina E. Aifantis
Download or read book High Energy Density Lithium Batteries written by Katerina E. Aifantis and published by John Wiley & Sons. This book was released on 2010-03-30 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials Engineering for High Density Energy Storage provides first-hand knowledge about the design of safe and powerful batteries and the methods and approaches for enhancing the performance of next-generation batteries. The book explores how the innovative approaches currently employed, including thin films, nanoparticles and nanocomposites, are paving new ways to performance improvement. The topic's tremendous application potential will appeal to a broad audience, including materials scientists, physicists, electrochemists, libraries, and graduate students.
Book Synopsis Electrochemical Capacitors by : Seiji Kumagai
Download or read book Electrochemical Capacitors written by Seiji Kumagai and published by MDPI. This book was released on 2020-12-29 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrochemical capacitors are being increasingly introduced in energy storage devices, for example, in automobiles, renewable energies, and mobile terminals. This book includes five high-quality papers that can lead to technological developments in electrochemical capacitors. The first paper describes the effect of the milling degree of activated carbon particles used in the electrodes on the supercapacitive performance of an electric double-layer capacitor. The second, fourth, and fifth papers describe novel electrode materials that have the potential to enhance the performance of next-generation electrochemical capacitors. Nickel molybdate/reduced graphene oxide nanocomposite, copper-decorated carbon nanotubes, and nickel hydroxide/activated carbon composite are tested, and are shown to be promising candidates for next-generation electrochemical capacitors. The third paper reports the hybrid utilization of electrochemical capacitors with other types of energy devices (photovoltaics, fuel cells, and batteries) in a DC microgrid, which ensures wider applications of electrochemical capacitors in the near future. The knowledge and experience in this book are beneficial in manufacturing and utilizing electrochemical capacitors. Cutting-edge knowledge related to novel electrode nano-materials is also helpful to design next-generation electrochemical capacitors. This book delivers useful information to specialists involved in energy storage technologies.
Book Synopsis Low-carbon Supercapacitors by : M Basheer Ahamed
Download or read book Low-carbon Supercapacitors written by M Basheer Ahamed and published by Royal Society of Chemistry. This book was released on 2023-12-20 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supercapacitors can both hold large amounts of energy and charge up almost instantly. They have higher energy densities, higher efficiencies and longer lifetimes so can be used in a wide range of energy harvesting and storage systems including portable power and grid applications. Despite offering key performance advantages, many device components pose significant environmental hazards, often containing fluorine, sulfur and cyanide groups which are harmful when discarded. In recent years, there has been increasing research into more sustainable electrode materials for supercapacitor applications. In this book, readers are introduced to the extensive and ongoing research on the rationalization of low-carbon supercapacitor materials, their structures at varying scales and dimensions, the development of effective and low-cost synthesis techniques, design and architecture of green materials, as well as clarification of their electrochemical performance. It is an ideal book for researchers and industry professionals at the energy–environment nexus, searching for new advancements in supercapacitor science and technologies.
Book Synopsis Materials for Sustainable Energy by : Vincent Dusastre
Download or read book Materials for Sustainable Energy written by Vincent Dusastre and published by World Scientific. This book was released on 2011 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: The search for cleaner, cheaper, smaller and more efficient energy technologies has to a large extent been motivated by the development of new materials. The aim of this collection of articles is therefore to focus on what materials-based solutions can offer and show how the rationale design and improvement of their physical and chemical properties can lead to energy-production alternatives that have the potential to compete with existing technologies. In terms of alternative means to generate electricity that utilize renewable energy sources, the most dramatic breakthroughs for both mobile (i.e., transportation) and stationary applications are taking place in the fields of solar and fuel cells. And from an energy-storage perspective, exciting developments can be seen emerging from the fields of rechargeable batteries and hydrogen storage.
Book Synopsis Metal Oxides in Supercapacitors by : Deepak P. Dubal
Download or read book Metal Oxides in Supercapacitors written by Deepak P. Dubal and published by Elsevier. This book was released on 2017-07-10 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal Oxides in Supercapacitors addresses the fundamentals of metal oxide-based supercapacitors and provides an overview of recent advancements in this area. Metal oxides attract most of the materials scientists use due to their excellent physico-chemical properties and stability in electrochemical systems. This justification for the usage of metal oxides as electrode materials in supercapacitors is their potential to attain high capacitance at low cost. After providing the principles, the heart of the book discusses recent advances, including: binary metal oxides-based supercapacitors, nanotechnology, ternary metal oxides, polyoxometalates and hybrids. Moreover, the factors affecting the charge storage mechanism of metal oxides are explored in detail. The electrolytes, which are the soul of supercapacitors and a mostly ignored character of investigations, are also exposed in depth, as is the fabrication and design of supercapacitors and their merits and demerits. Lastly, the market status of supercapacitors and a discussion pointing out the future scope and directions of next generation metal oxides based supercapacitors is explored, making this a comprehensive book on the latest, cutting-edge research in the field. Explores the most recent advances made in metal oxides in supercapacitors Discusses cutting-edge nanotechnology for supercapacitors Includes fundamental properties of metal oxides in supercapacitors that can be used to guide and promote technology development Contains contributions from leading international scientists active in supercapacitor research and manufacturing
Book Synopsis Electrochemical Impedance Spectroscopy by : Mark E. Orazem
Download or read book Electrochemical Impedance Spectroscopy written by Mark E. Orazem and published by John Wiley & Sons. This book was released on 2011-10-13 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using electrochemical impedance spectroscopy in a broad range of applications This book provides the background and training suitable for application of impedance spectroscopy to varied applications, such as corrosion, biomedical devices, semiconductors and solid-state devices, sensors, batteries, fuel cells, electrochemical capacitors, dielectric measurements, coatings, electrochromic materials, analytical chemistry, and imaging. The emphasis is on generally applicable fundamentals rather than on detailed treatment of applications. With numerous illustrative examples showing how these principles are applied to common impedance problems, Electrochemical Impedance Spectroscopy is ideal either for course study or for independent self-study, covering: Essential background, including complex variables, differential equations, statistics, electrical circuits, electrochemistry, and instrumentation Experimental techniques, including methods used to measure impedance and other transfer functions Process models, demonstrating how deterministic models of impedance response can be developed from physical and kinetic descriptions Interpretation strategies, describing methods of interpretating of impedance data, ranging from graphical methods to complex nonlinear regression Error structure, providing a conceptual understanding of stochastic, bias, and fitting errors in frequency-domain measurements An overview that provides a philosophy for electrochemical impedance spectroscopy that integrates experimental observation, model development, and error analysis This is an excellent textbook for graduate students in electrochemistry, materials science, and chemical engineering. It's also a great self-study guide and reference for scientists and engineers who work with electrochemistry, corrosion, and electrochemical technology, including those in the biomedical field, and for users and vendors of impedance-measuring instrumentation.
Book Synopsis Amorphous Nanomaterials by : Lin Guo
Download or read book Amorphous Nanomaterials written by Lin Guo and published by John Wiley & Sons. This book was released on 2021-06-01 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: A valuable overview covering important fundamental and applicative aspects of amorphous nanomaterials! Amorphous nanomaterials are very important in non-crystalline solids, which have emerged as a new category of advanced materials. Compared to the crystalline counterpart, amorphous nanomaterials with isotropic nature always exhibit fast ion diffusion, relieved strain, and higher reactivity, enabling such materials to exhibit high performance in mechanics and catalysis, as well as other interesting properties. Amorphous Nanomaterials: Preparation, Characterization, and Applications covers the fundamental concept, synthesis, characterization, properties, and applications of nanoscaled amorphous materials. It starts with the introduction of amorphous materials, then gives a global view of the history, structure, and growth mechanism of amorphous nanomaterials. Subsequently, some powerful techniques to characterize amorphous materials, such as X-ray absorption fine structure spectroscopy, spherical aberration electron microscope, in-situ-Transmission Electron Microscope, Electron Energy Loss Spectroscopy, and some other defect characterization technologies are included. Furthermore, the emerging innovative methods to fabricate well-defined, regularshaped amorphous nanomaterials, including zero-, one-, two-, and three-dimensional amorphous nanomaterials are systematically introduced. The fascinating properties and applications related to amorphous nanomaterials including the applications in electrocatalysis, batteries, supercapacitors, photocatalysis, mechanics, etc., are presented. It will greatly help the researchers to find professional answers related to amorphous materials. Great topic: amorphous nanomaterials are a very large and important field in both academia and industry Comprehensive: in-depth discussion of various important aspects, from both a fundamental and an applied point of view, on the chemistry, physics and technological importance of the amorphous nanomaterials are presented Vitally needed: the understanding of the fundamentals of amorphous nanomaterials is a prerequisite for devising new applications of such materials Highly relevant: amorphous nanomaterials have found specific applications in chemistry, catalysis, physics, sensing, batteries, supercapacitors, and engineering Amorphous Nanomaterials is a vital resource for materials scientists, inorganic and physical chemists, solid state chemists, physicists, catalytic and analytical chemists, as well as organic chemists.
