Download or read book Arginine modification of hybrid cobalt nitrogen Ti3C2Tx MXene and its application as a sulfur host for lithium sulfur batteries written by Miao Zhang and published by OAE Publishing Inc.. This book was released on 2024-03-05 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The shuttling effect of lithium polysulfides (LiPSs) is one of the challenges facing the commercialization, which leads to a significant capacity degradation. This paper proposes a novel method to promote polysulfide transformation by employing arginine to regulate the layer spacing of cobalt-nitrogen doped Ti3C2Tx MXene (Co-N@Ti3C2Tx-Arg). The results revealed that arginine effectively extended the interlayer spacing and promoted the homogeneous dispersion of Co and N atoms, thus endowing the sulfur host with a high catalytic activity during the charging and discharging processes. The extended interlayer spacing increased the specific surface area and captured sufficient LiPSs for subsequent catalytic conversions, while the Co and N doping on the surface of Ti3C2Tx significantly promoted the rapid conversion of the LiPSs to Li2S. Therefore, the S cathode coated with Co-N@Ti3C2Tx-Arg exhibited an excellent cycling stability with a low-capacity fading rate of 0.083% over 200 cycles in addition to a high reversible capacity of 1,365.4 mAh g-1 at 0.1 C.

Download or read book Cell Modification Strategies for High energy Lithium sulfur Batteries written by Liu Luo and published by . This book was released on 2019 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lithium-sulfur (Li-S) batteries have drawn tremendous interest in the next-generation energy-storage field due to the high theoretical capacity (1675 mA h g−1) and low cost of the eco-friendly sulfur. Nevertheless, the practical realization of Li-S technology is still challenging. The major bottleneck lies in the insulating nature of sulfur and its redox products, together with the shuttling of intermediate polysulfides (Li2S [subscript x], 4 ≤ x ≤ 8) during cycling, leading to low active-material utilization and fast capacity fade. This dissertation focuses on the development of advanced cell configurations with novel modification strategies to improve the electrochemical performance of Li-S cells. First, a multi-layer-coated separator is established to suppress the polysulfide migration. The functional coating films act as net-like filters to intercept the diffusing polysulfides by both physical and chemical interactions, contributing to enhanced cycling stability and capacity retention. Second, a new sulfur cathode configuration with a poached-egg-shaped architecture is proposed to improve the cyclability of Li-S cells. The carbon shell not only achieves an effective physical encapsulation of the "sulfur yolk" to localize active material, but also serves as interlinked electron pathways to favor the active-material reactivation, greatly enhancing the electrochemical utilization and reversibility. Third, in addition to the physical polysulfide-entrapment, the chemical adsorbent is also introduced into the sulfur cathode substrate. By coupling the sulfiphilic metal compounds (e.g., NiS2 and SnS2) with a conductive carbon framework to construct a hybrid sulfur host, the polysulfide adsorptivity is significantly improved due to the physical confinement and chemical anchoring, further limiting the active-material loss and polysulfide diffusion. Fourth, another novel cathode design with electrocatalyst incorporation is presented to enhance the rate capability and cycle life of Li-S cells. The electrocatalysts (e.g., Ni and B4C) function as efficient redox mediators to accelerate the reaction kinetics of polysulfide transformation, leading to highly promoted active-material utilization and rate performance. Finally, an advanced Li-metal host is also designed with a three-dimensional lithiophilic architecture. The lithiophilic seeds (e.g., Mo2N) substantially lower the Li nucleation overpotential, thus spatially guiding the uniform Li deposition in the conductive matrix and suppressing the Li-dendrite formation as well as Li anode degradation

Download or read book Advanced Electrodes and Electrolytes for Long lived and High energy density Lithium sulfur Batteries written by Quanquan Pang and published by . This book was released on 2017 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing demand on renewable but intermittent energy and the need for electrified transportation place great emphasis on energy storage. Lithium-sulfur (Li-S) batteries are promising systems due to the high theoretical energy density and natural abundance of sulfur. This thesis presents a thorough investigation on strategies to confine the polysulfides and to build long-lived and high-energy-density Li-S batteries. A series of sulfur host materials and a class of sparingly solvating electrolyte are presented. Chapter 3 presents an approach to confine polysulfides within a cobalt sulfide material, which exhibits both metallic conductivity and high polysulfide adsorptivity. First-principles calculations and X-ray photoelectron spectroscopy studies consistently demonstrate the coupled interaction between the ionic components of cobalt sulfide and lithium polysulfides. The interconnected nanosheets form 3D networks and enable high sulfur loading electrodes with stable cycling. Chapter 4 presents a novel dual-doping strategy on porous carbon for effective binding of polysulfides. The N and S heteroatoms respectively bond with the Li cations and S anions in the polysulfides. The synthesis is based on liquid-crystal driven self-assembly of bio-sustainable cellulose nanocrystals. Chapter 5 reports a light-weight graphitic carbon nitride material that incorporates high concentration of active N-doping sites for polysulfide binding. Excellent long-term cycling performance of the sulfur electrode is achieved with only 0.04% capacity fading per cycle over 1500 cycles. Chapter 6 further reports a comprehensive strategy on coupling a hybrid sulfur host with an in-situ cross-linked binder in order to construct high loading electrodes while using a low electrolyte volume. Alternative stacking of graphitic carbon nitride and graphene offers both Li-N based adsorption for polysulfide and high electronic conductivity. Benefiting from the high elasticity of the cross-linked binder, crack-free high loading electrodes are fabricated at an electrolyte/sulfur ratio of 3.5:1 ([mu]l:mg). Chapter 7 presents a comprehensive study on the ACN2-LiTFSI-TTE electrolyte with sparing solubility for polysulfides at elevated temperature. A quasi-solid state reaction is demonstrated by the distinct Li-S voltage profiles and sulfur/lithiu sulfide phase evolution as probed by operando XRD measurements. This discovery will inspire further studies into modifying the local structure of electrolytes to control the reaction pathways of dissolution-precipitation electrochemistry.

Download or read book Development of High Loading Lithium Sulfur Battery written by Matthew Li and published by . This book was released on 2016 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: The topic of batteries has been given much attention. With the development and rapid improvement of transistors, the power requirement of our electronics are quickly becoming higher and higher. Unlike Moore's law, since the commercialization of its newest iteration, the lithium ion battery (LIB) the battery technology has shown only incremental improvement. Popular fashionable companies such as Tesla has developed electric vehicles with acceptable mileage of around 400 km per change. Even with Elon Musk's ambitious goals, championing the change in the whole automotive industry, scientific barriers are met as the theoretical limits of the battery materials are reached. To answer to this, researchers around the globe have revisited old and thought to be too difficult to implement technologies such as the lithium sulfur battery (LIS). A LIS possesses a sulfur cathode and a lithium anode, which leads to one key advantage to LIBs, sulfur can store/bond to lithium at much higher ratios than traditional cathodes in LIBs. Boasting a theoretical energy density of about 5 times that of the current LIB, this technology has the potential to ultimately surpass and replace a lot of the LIB out in the market. Unfortunately, the reason it was given up decades ago was due to its debilitating problems. First and foremost, sulfur is a very good insulator making it difficult to efficiently deliver electrons to its reaction sites. Furthermore, during discharge and charge sulfur will dissolve into the electrolyte, upon deposition on insulating spots in the cell it disconnects itself from the circuit. In short the LIS are not durable and suffers from terrible cycle life. To address these challenges, researchers have develop many clever engineering designs such as modification to the electrodes, electrolyte, separator, anode all of which have shown great promise on the lab scale resulting in LIS with impressive performance surpassing LIBs. The first part of this thesis will be to develop a type of nitrogen doped porous carbon material that will serve as a modifier for the cathode improving its performance over bare sulfur cathodes. A first discharge of 1060 mAh g-1 was achieved at 0.2C and stabilized to ~860 mAh g-1 , a ~81 % retention in capacity over 100cycles. This material also offered significant improvements in rate performance. It was able to discharge at 5C delivering ~600 mAh g-1. Both the cycle stability and rate performance illustrates the impact of using nitrogen doping for LIS. In order for LIS to reach the market the one key parameter has to be addressed first and that is the loading of sulfur in the battery. Many of publications have displayed near theoretical/ideal performances, seemingly revolutionizing the battery industry, but unfortunately at impractically low loadings. Continuing from the low loading high performance electrodes of the first part of this thesis, the work in the second part will improve upon the porous carbon material allowing its application in high loading electrodes. It was quickly discovered that the nano-sized nitrogen doped porous carbon was unable to yield a robust electrode at higher loadings. Cracks and pinholes formed throughout the electrode leading to the eventual flaking/delamination of material. Larger nitrogen-doped porous carbon was synthesized through a simple addition of NaCl into the synthesis procedure. This aggregated the smaller polymer particles together forming micron size particles. Larger nitrogen doped porous carbon easily formed thick electrodes while at the same time achieved exceptional electrochemical performance. With a discharge rate of 0.1C a specific capacity of 1300 mAh g-1 was reached stabilizing to 1050 mAh g-1 after 50 cycles. Moreover, at 0.2C and 0.5C discharge rates this material delivered ~1000 mAh g-1 and 900 mAh g-1 respectively on first discharge.

Download or read book 2D Metal Carbides and Nitrides MXenes written by Babak Anasori and published by Springer Nature. This book was released on 2019-10-30 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the rapidly expanding field of two-dimensional (2D) transition metal carbides and nitrides (MXenes). It covers fundamental knowledge on synthesis, structure, and properties of these new materials, and a description of their processing, scale-up and emerging applications. The ways in which the quickly expanding family of MXenes can outperform other novel nanomaterials in a variety of applications, spanning from energy storage and conversion to electronics; from water science to transportation; and in defense and medical applications, are discussed in detail.

Download or read book MXenes and their Composites written by Kishor Kumar Sadasivuni and published by Elsevier. This book was released on 2021-10-07 with total page 796 pages. Available in PDF, EPUB and Kindle. Book excerpt: MXenes and their Composites: Synthesis, Properties and Potential Applications presents a state of the art overview of the recent developments on the synthesis, functionalization, properties and emerging applications of two-dimensional (2D) MXenes and their composites.The book systematically describes the state-of-the-art knowledge and fundamentals of MXene synthesis, structure, surface chemistry and functionalization. The book also discusses the unique electronic, optical, mechanical and topological properties of MXenes. Besides, this book covers the various emerging applications of MXenes and their composites across different fields such as energy storage and conversion, gas sensing and biosensing, rechargeable lithium and sodium-ion batteries, lithium-sulphur and multivalent batteries, electromagnetic interference shielding, hybrid capacitors and supercapacitors, hydrogen storage, catalysis and photoelectrocatalysis, gas separation and water desalination, environmental remediation and medical and biomedical applications. All these applications have been efficiently discussed in the specific chapters and in each case, the processing of MXene composites has also been discussed.This book will be an excellent reference for scientists and engineers across various disciplines and industries working in the field of highly promising 2D MXenes and their composites. The book will also act as a guide for academic researchers, material scientists, and advanced students in investigating the new applications of 2D MXenes based materials. Covers fundamentals of technologically important MAX phases, MXene derivatives, MXene synthesis methods, intercalation and delamination strategies, surface functionalization, fundamental characteristics and properties Demonstrates major application areas of MXenes, including catalytic, energy storage and energy generation, flexible electronics, EMI shielding, sensors and biosensors, medical and biomedical, gas separation and water desalination Presents a detailed discussion on the processing and performance of various MXenes towards different applications

Download or read book Milestones in Microbiology written by Thomas D. Brock and published by . This book was released on 1961 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Carbon Nanotubes written by Mohammed Rahman and published by BoD – Books on Demand. This book was released on 2018-04-26 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book Carbon Nanotubes - Recent Progress contains a number of recent researches on synthesis, growth, characterization, development, and potential applications on carbon materials especially CNTs in nanoscale. It is a promising novel research from top to bottom that has received a lot of interest in the last few decades. It covers the advanced topics on the physical, chemical, and potential applications of CNTs. Here, the interesting reports on cutting-edge science and technology related to synthesis, morphology, control, hybridization, and prospective applications of CNTs are concluded. This potentially unique work offers various approaches on the R

Download or read book Lignin Valorization written by Gregg T. Beckham and published by Royal Society of Chemistry. This book was released on 2018-03-29 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Chapters will specifically focus on the production of fuels and chemicals from lignin."--Page [4] of cover.

Download or read book 4D Electron Microscopy written by Ahmed H. Zewail and published by World Scientific. This book was released on 2010 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structural phase transitions, mechanical deformations, and the embryonic stages of melting and crystallization are examples of phenomena that can now be imaged in unprecedented structural detail with high spatial resolution, and ten orders of magnitude as fast as hitherto. No monograph in existence attempts to cover the revolutionary dimensions that EM in its various modes of operation nowadays makes possible. The authors of this book chart these developments, and also compare the merits of coherent electron waves with those of synchrotron radiation. They judge it prudent to recall some important basic procedural and theoretical aspects of imaging and diffraction so that the reader may better comprehend the significance of the new vistas and applications now afoot. This book is not a vade mecum - numerous other texts are available for the practitioner for that purpose.

Download or read book An Introduction to Green Nanotechnology written by Mahmoud Nasrollahzadeh and published by Academic Press. This book was released on 2019-03-01 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: An Introduction to Green Nanotechnology, Volume 28, provides students, scientists and chemical engineers with an overview of several types of nanostructures, discusses the synthesis and characterization of nanostructures, and provides applications of nanotechnology in daily life. The book offers a foundation to green nanotechnology by explaining why green nanotechnology is important. Covers biological sources in green nanotechnology, antioxidants, green nanostructures, mechanism, synthesis and characterization. The book ends with an evaluation of the risks of nanotechnology in human life and future perspectives. Introduces novel sources of plants having a high potential to be used as bio media to synthesize nanostructures Provides phytochemical properties and antioxidant potential, and their effects on stability, morphology and size of green nanostructures Includes a medicinal and technological comparison of green synthesized nanostructures to nano-products from non-green methods Uses accessible language, avoiding complex concepts of mathematics, biology and chemistry

Download or read book Nanoparticles in Medicine written by Ashutosh Kumar Shukla and published by Springer Nature. This book was released on 2019-08-31 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the medical applications of inorganic nanoparticles. Nanomedicine is a relatively advanced field, which enhances the treatment of various diseases, offering new options for overcoming the problems associated with the use of conventional medicines. Discussing the toxicological and safety aspects associated with medical applications of nanoparticles, the book presents the latest research on topics such as emerging nanomaterials for cancer therapy, applications of nanoparticles in dentistry, and fluoride nanoparticles for biomedical applications, and also includes chapters on the use of nanoparticles such as silver and gold. /div

Download or read book Comprehensive Inorganic Chemistry written by and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sustainable Industrial Chemistry written by Fabrizio Cavani and published by John Wiley & Sons. This book was released on 2009-09-22 with total page 621 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years the need for sustainable process design and alternative reaction routes to reduce industry?s impact on the environment has gained vital importance. The book begins with a general overview of new trends in designing industrial chemical processes which are environmentally friendly and economically feasible. Specific examples written by experts from industry cover the possibilities of running industrial chemical processes in a sustainable manner and provide an up-to-date insight into the main concerns, e.g., the use of renewable raw materials, the use of alternative energy sources in chemical processes, the design of intrinsically safe processes, microreactor and integrated reaction/ separation technologies, process intensification, waste reduction, new catalytic routes and/or solvent and process optimization.

Download or read book Inventing Reactions written by Lukas J. Gooßen and published by Springer. This book was released on 2012-10-30 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: Barry Trost: Transition metal catalyzed allylic alkylation.- Jeffrey W. Bode: Reinventing Amide Bond Formation.- Naoto Chatani and Mamoru Tobisu: Catalytic Transformations Involving the Cleavage of C-OMe Bonds.- Gregory L. Beutner and Scott E. Denmark: The Interplay of Invention, Observation and Discovery in the Development of Lewis Base Activation of Lewis Acids for Catalytic Enantioselective Synthesis.- David R. Stuart and Keith Fagnou: The Discovery and Development of a Palladium(II)-Catalyzed Oxidative Cross-Coupling of Two Unactivated Arenes.- Lukas Gooßen and Käthe Gooßen: Decarboxylative Cross-Coupling Reactions.- A. Stephen K. Hashmi: Gold-Catalyzed Organic Reactions.- Ben List: Developing Catalytic Asymmetric Acetalizations.- Steven M. Bischof, Brian G. Hashiguchi, Michael M. Konnick, and Roy A. Periana: The De NovoDesign of CH Bond Hydroxylation Catalysts.- Benoit Cardinal-David, Karl A. Scheidt: Carbene Catalysis: Beyond the Benzoin and Stetter Reactions.- Kenso Soai and Tsuneomi Kawasaki: Asymmetric autocatalysis of pyrimidyl alkanol.- Douglas C. Behenna and Brian M. Stoltz: Natural Products as Inspiration for Reaction Development: Catalytic Enantioselective Decarboxylative Reactions of Prochiral Enolate Equivalents. Hisashi Yamamoto: Acid Catalysis in Organic Synthesis.

Download or read book Hybrid Nanofluids written by Zafar Said and published by Elsevier. This book was released on 2022-01-28 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hybrid Nanofluids: Preparation, Characterization and Applications presents the history of hybrid nanofluids, preparation techniques, thermoelectrical properties, rheological behaviors, optical properties, theoretical modeling and correlations, and the effect of all these factors on potential applications, such as solar energy, electronics cooling, heat exchangers, machining, and refrigeration. Future challenges and future work scope have also been included. The information from this book enables readers to discover novel techniques, resolve existing research limitations, and create novel hybrid nanofluids which can be implemented for heat transfer applications. Describes the characterization, thermophysical and electrical properties of nanofluids Assesses parameter selection and property measurement techniques for the calibration of thermal performance Provides information on theoretical models and correlations for predicting hybrid nanofluids properties from experimental properties

Download or read book Head and Neck Face written by University of North Carolina Chapel Hill and published by Elsevier Health Sciences. This book was released on 2019-08-31 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Head and Neck - Face