Study Of Lithium Deposition And Applicability Of Solid Polymer Electrolytes In Lithium Cells Band 10

Lithium (Li) deposition is a problem in Li batteries (LB) – both Li metal (LMB) and Li-ion (LIB) batteries – which limits their performance in terms of power and energy density. Two trends can be identified in the advancement of LBs concerning the problem of Li deposition: optimization of the existing system (the state-of-the-art LIBs) and further development of cell components such as electrolytes. This work addresses both approaches. In the first part, this study investigates Li deposition in LMB and LIBs. A novel method to study the Li-based transport mechanisms in LIBs is introduced. Later the kinetic deviations between anode and cathode as a consequence of aging and the relation of these deviations to the occurrence of Li-plating are discussed. In the second part, the applicability of PEO-based solid polymer electrolytes for LMBs to overcome the Li plating issue is investigated. The introduction of various interfacial interlayers at the cathode/electrolyte interphase was studied to improve the electrochemical stability of the cells. Cells with an in-situ electro-deposited interlayer showed the best cyclability.

This thesis makes significant advances in the design of electrolytes and interfaces in electrochemical cells that utilize reactive metals as anodes. Such cells are of contemporary interest because they offer substantially higher charge storage capacity than state-of-the-art lithium-ion battery technology. Batteries based on metallic anodes are currently considered impractical and unsafe because recharge of the anode causes physical and chemical instabilities that produce dendritic deposition of the metal leading to catastrophic failure via thermal runaway. This thesis utilizes a combination of chemical synthesis, physical & electrochemical analysis, and materials theory to investigate structure, ion transport properties, and electrochemical behaviors of hybrid electrolytes and interfacial phases designed to prevent such instabilities. In particular, it demonstrates that relatively low-modulus electrolytes composed of cross-linked networks of polymer-grafted nanoparticles stabilize electrodeposition of reactive metals by multiple processes, including screening electrode electrolyte interactions at electrochemical interfaces and by regulating ion transport in tortuous nanopores. This discovery is significant because it overturns a longstanding perception in the field of nanoparticle-polymer hybrid electrolytes that only solid electrolytes with mechanical modulus higher than that of the metal electrode are able to stabilize electrodeposition of reactive metals.

This book provides comprehensive coverage of Lithium (Li) metal anodes for rechargeable batteries. Li is an ideal anode material for rechargeable batteries due to its extremely high theoretical specific capacity (3860 mAh g-1), low density (0.59 g cm-3), and the lowest negative electrochemical potential (−3.040 V vs. standard hydrogenelectrodes). Unfortunately, uncontrollable dendritic Li growth and limited Coulombic efficiency during Li deposition/stripping inherent in these batteries have prevented their practical applications over the past 40 years. With the emergence of post Liion batteries, safe and efficient operation of Li metal anodes has become an enabling technology which may determine the fate of several promising candidates for the next generation energy storage systems, including rechargeable Li-air batteries, Li-S batteries, and Li metal batteries which utilize intercalation compounds as cathodes. In this work, various factors that affect the morphology and Coulombic efficiency of Li anodes are analyzed. The authors also present the technologies utilized to characterize the morphology of Li deposition and the results obtained by modeling of Li dendrite growth. Finally, recent developments, especially the new approaches that enable safe and efficient operation of Li metal anodes at high current densities are reviewed. The urgent need and perspectives in this field are also discussed. The fundamental understanding and approaches presented in this work will be critical for the applicationof Li metal anodes. The general principles and approaches can also be used in other metal electrodes and general electrochemical deposition of metal films.

In this review, different types of electrolytes and their electrical and mechanical properties have been reported and studied to evaluate their effect on LIB performance. It was noticed that the electrolyte component and solvent in polymer electrolytes have a great influence on the ionic conductivity, Li+ migration, interfacial contact between electrolyte and electrode, mechanical properties, and the performance of the entire battery. The morphology of incorporated additive materials (nanoparticles, nanowires, nanofillers, salt, etc.) may well contribute to the amelioration of the ion transport pathway, which raises the lithium-ion conductivity. A basic understanding of the chemical reaction routes and the electrolyte structure would facilitate innovation in the battery. The structural, electrochemical, and mechanical properties of new promising materials should be investigated in advance for application in advanced lithium-ion batteries. The electrochemical behavior is inextricably related to the structure. IL-based solid polymer electrolytes appear as a promising material for long-term lithium-ion batteries despite showing low ionic conductivity but exhibiting more advantages than conventional carbonate electrolytes such as good safety, stability, good electrochemical performance, good mechanical stability, and enhanced energy density. Since solid electrolytes exhibit low ionic conductivity, ILs used in SPEs increased their conductivity. In a battery, porous materials appear to offer good properties in terms of lithium ionic conductivity, with no leakage and low interface resistance, and gel-based LIBs demonstrate a good working performance, long cycling life, and high energy density. Good polymer electrolytes need to be highly conductive, safe, highly mechanically and thermally stable, and easy for film formation.

Phosphoric Acids—Advances in Research and Application: 2012 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Phosphoric Acids. The editors have built Phosphoric Acids—Advances in Research and Application: 2012 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Phosphoric Acids in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Phosphoric Acids—Advances in Research and Application: 2012 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Starting out with an introduction to the fundamentals of lithium ion batteries, this book begins by describing in detail the new materials for all four major uses as cathodes, anodes, separators, and electrolytes. It then goes on to address such critical issues as self-discharge and passivation effects, highlighting lithium ion diffusion and its profound effect on a battery's power density, life cycle and safety issues. The monograph concludes with a detailed chapter on lithium ion battery use in hybrid electric vehicles. Invaluable reading for materials scientists, electrochemists, physicists, and those working in the automobile and electrotechnical industries, as well as those working in computer hardware and the semiconductor industry.