Lithium-Ion Battery and Beyond: Oxygen Vacancy Creation in Tungsten Trioxide and Surface Modification of Lithium Metal

The graphite-based anode material has a low theoretical specific capacity of 371 mAh g-1. The transitional metal oxides (TMOs) are considered a better choice owing to their relatively higher specific capacity. Among TMOs, tungsten trioxide (WO3) is considered promising due to a higher specific capacity of 693 mAh g-1, low cost, mechanically stable, and eco-friendly. It has been a challenge to utilize the TMOs as anode materials as they suffer from poor electronic conductivity and large electrode volume expansion during discharge/charge cycles. In our first project, we demonstrate a unique self-recovery of capacity in reduced WO3 by the incorporation of urea followed by annealing at 500 °C under the N2 environment. The reduced WO3 exhibited a unique cycling phenomenon, where the capacity was significantly self-recovered after an initial sharp decrease. This can be attributed to the activation of oxygen vacancy sites or defects, making the WO3 electrode more electrochemically active with cycling. In our second and third projects, we modify the surface of lithium metal to utilize them as anode because LIBs are approaching their theoretical energy density limit. Lithium metal anodes are expected to drive practical applications that require high energy-density storage. However, the direct use of metallic lithium causes safety concerns, low rate capabilities, and poor cycling performances due to unstable solid electrolyte interphase (SEI) and undesired lithium dendrite growth. To address these issues, in our second project, radio frequency (R-F) sputtered graphite-SiO2 ultrathin bilayer on a Li metal chips was demonstrated, for the first time, as an effective solid-electrolyte interface (SEI) layer. In the third project, we developed a facile, costeffective, and one-step approach to generate an artificial lithium metal/electrolyte interphase by treating lithium anode with an electrolyte containing tin fluoride. The development of artificial SEI on top of lithium metal anode led to a dendrite free uniform Li deposition to achieve a stable voltage profile and outstanding long hours plating/stripping compared to the bare Li. The generated SEI not only ensures fast lithiumion diffusion and suppression of lithium dendrite growth but also brings a synergistic effect of storing lithium via a reversible silicon-lithium or tin-lithium alloy formation and lithium plating

Space programs summary no. 37-49, volume 3 for the period December 1, 1967 to January 30, 1968. Supporting research and advanced development

Space program research projects on systems analysis and engineering, telecommunications, guidance and control, propulsion, and data system

A History of Materials and Technologies Development

The purpose of the book is to provide the students with the text that presents an introductory knowledge about the development of materials and technologies and includes the most commonly available information on human development. The idea of the publication has been generated referring to the materials taken from the organic and non-organic evolution of nature. The suggested texts might be found a purposeful tool for the University students proceeding with studying engineering due to the fact that all subjects in this particular field more or less have to cover the history and development of the studied object. It is expected that studying different materials and technologies will help the students with a better understanding of driving forces, positive and negative consequences of technological development, etc

MC 2019 Berlin Microscopy Conference - Abstracts

Das Dokument enthält die Kurzfassungen der Beiträge aller Teilnehmer an der Mikroskopiekonferenz "MC 2019", die vom 01. bis 05.09.2019, in Berlin stattfand

A critical investigation of the semantic and morphological aspects of terminological incompetence (with special reference to the English-speaking student of Physical Science and History in the Cape Education Department high school)

From Background to the thesis: It has been said that 'educational failure is language failure'. It can be argued here that there are many other factors which could cause educational failure and that language failure does not necessarily result in lack of academic success. However, it is no doubt true that the schoolchild who does not attain a certain type of language competence will be handicapped as regards academic performance. The underlying reason for this is the fact that our educational system is heavily reliant on language - and espacially the written language - as a medium of learning as opposed to the 'direct learning' experiences advocated by certain educationists today such as Ivan Illich in America and John Holt in Britain. Language is the basis both of learning and of communicating what has been learnt. From the moment the child steps into his first period class in the morning till he leaves the last five hours later the child is involved in what is primarily a verbal experience