There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

The flow of homogeneous fluids through porous media: analogies with other physical problems

Owing to high specific energy, low cost, and environmental friendliness, lithium–sulfur (Li–S) batteries hold great promise to meet the increasing demand for advanced energy storage beyond portable electronics, and to mitigate environmental problems. However, the application of Li–S batteries is challenged by several obstacles, including their short life and low sulfur utilization, which become more serious when sulfur loading is increased to the practically accepted level above 3–5 mg cm−2. More and more efforts have been made recently to overcome the barriers toward commercially viable Li–S batteries with a high sulfur loading. This review highlights the recent progress in high-sulfur-loading Li–S batteries enabled by hierarchical design principles at multiscale. Particularly, basic insights into the interfacial reactions, strategies for mesoscale assembly, unique architectures, and configurational innovation in the cathode, anode, and separator are under specific concerns. Hierarchy in the multiscale design is proposed to guide the future development of high-sulfur-loading Li–S batteries.

Review on High-Loading and High-Energy Lithium–Sulfur Batteries

Lithium-sulfur (Li-S) batteries have attracted tremendous interest because of their high theoretical energy density and cost effectiveness. The target of Li-S battery research is to produce batteries with a high useful energy density that at least outperforms state-of-the-art lithium-ion batteries. However, due to an intrinsic gap between fundamental research and practical applications, the outstanding electrochemical results obtained in most Li-S battery studies indeed correspond to low useful energy densities and are not really suitable for practical requirements. The Li-S battery is a complex device and its useful energy density is determined by a number of design parameters, most of which are often ignored, leading to the failure to meet commercial requirements. The purpose of this review is to discuss how to pave the way for reliable Li-S batteries. First, the current research status of Li-S batteries is briefly reviewed based on statistical information obtained from literature. This includes an analysis of how the various parameters influence the useful energy density and a summary of existing problems in the current Li-S battery research. Possible solutions and some concerns regarding the construction of reliable Li-S batteries are comprehensively discussed. Finally, insights are offered on the future directions and prospects in Li-S battery field.

More Reliable Lithium-Sulfur Batteries: Status, Solutions and Prospects.

Clear experimental evidence from X-ray photoelectron spectroscopy and 31P NMR spectroscopy has been obtained for the first time to confirm that the combination of Ag+ cation with [L-Au]+ results in the formation of different complexes in solution. Re-evaluation of literature-reported gold-catalyzed reactions revealed a significant difference in the reactivities with and without silver. In extreme cases (more than “rare”), the conventional [L-Au]+ catalysts could not promote the reaction without the presence of silver. This investigation has therefore revealed a long-overlooked “silver effect” in gold catalysis and should lead to revision of the actual mechanism.

"Silver effect" in gold(I) catalysis: an overlooked important factor.

Sulfur-tolerant anode materials for solid oxide fuel cell application

Recent Development of SOFC Metallic Interconnect

Rechargeable lithium-sulfur (Li-S) batteries are receiving ever-increasing attention due to their high theoretical energy density and inexpensive raw sulfur materials. However, their rapid capacity fade has been one of the key barriers for their further improvement. It is well accepted that the major degradation mechanisms of S-cathodes include low electrical conductivity of S and sulfides, precipitation of nonconductive Li2S2 and Li2S, and poly-shuttle effects. To determine these degradation factors, a comprehensive study of sulfur cathodes with different amounts of electrolytes is presented here. A survey of the fundamentals of Li-S chemistry with respect to capacity fade is first conducted; then, the parameters obtained through electrochemical performance and characterization are used to determine the key causes of capacity fade in Li-S batteries. It is confirmed that the formation and accumulation of nonconductive Li2S2/Li2S films on sulfur cathode surfaces are the major parameters contributing to the rapid capacity fade of Li-S batteries.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/advs.201600101

Capacity Fade Analysis of Sulfur Cathodes in Lithium-Sulfur Batteries.

The Li-ion battery represents one of the most important and most technically challenging components of electric vehicles The cathode is one of the three key components (ie, cathode, anode, and electrolyte) of the Li-ion battery and determines the battery quality The demand for higher energy density, lower cost, and environmentally friendly batteries makes Li-rich layered oxides xLi2MnO3·(1 − x)LiMO2 (LR-NMC) among the most attractive candidates for future cathode materials In this review, we discuss the state-of-the-art research activities related to LR-NMC materials, including their structures, mechanisms of high capacity and large voltage, challenges, and strategies that have been studied to improve their performances Finally, we conclude with some personal perspectives for the future development of LR-NMC materials

Xingbo Liu

Papers

"Silver effect" in gold(I) catalysis: an overlooked important factor.

Sulfur-tolerant anode materials for solid oxide fuel cell application

Recent Development of SOFC Metallic Interconnect

Capacity Fade Analysis of Sulfur Cathodes in Lithium-Sulfur Batteries.

Recent progress in Li-rich layered oxides as cathode materials for Li-ion batteries