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

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Each cell of a battery stores electrical energy as chemical energy in two electrodes, a reductant (anode) and an oxidant (cathode), separated by an electrolyte that transfers the ionic component of the chemical reaction inside the cell and forces the electronic component outside the battery. The output on discharge is an external electronic current I at a voltage V for a time Δt. The chemical reaction of a rechargeable battery must be reversible on the application of a charging I and V. Critical parameters of a rechargeable battery are safety, density of energy that can be stored at a specific power input and retrieved at a specific power output, cycle and shelf life, storage efficiency, and cost of fabrication. Conventional ambient-temperature rechargeable batteries have solid electrodes and a liquid electrolyte. The positive electrode (cathode) consists of a host framework into which the mobile (working) cation is inserted reversibly over a finite solid–solution range. The solid–solution range, which is...

The Li-ion rechargeable battery: a perspective.

Li-ion battery technology has become very important in recent years as these batteries show great promise as power sources that can lead us to the electric vehicle (EV) revolution. The development of new materials for Li-ion batteries is the focus of research in prominent groups in the field of materials science throughout the world. Li-ion batteries can be considered to be the most impressive success story of modern electrochemistry in the last two decades. They power most of today's portable devices, and seem to overcome the psychological barriers against the use of such high energy density devices on a larger scale for more demanding applications, such as EV. Since this field is advancing rapidly and attracting an increasing number of researchers, it is important to provide current and timely updates of this constantly changing technology. In this review, we describe the key aspects of Li-ion batteries: the basic science behind their operation, the most relevant components, anodes, cathodes, electrolyte solutions, as well as important future directions for R&D of advanced Li-ion batteries for demanding use, such as EV and load-leveling applications.

Challenges in the development of advanced Li-ion batteries: a review

Li-ion battery materials: present and future

As society becomes increasingly more dependent on electricity, the development of systems capable of storing directly or indirectly this secondary energy form will be a crucial issue for the 21st century. Batteries, which are devices converting the energy released by spontaneous chemical reactions to electricity work, have some extraordinary properties in these regards. They store and release electrical energy; they are portable and can be used flexibly with a short lead time in manufacture. In this brief introduction, we show the important functions of intercalation compounds used in advanced systems for energy storage.

Intercalation Compounds for Energy Storage

The commercial use of lithium metal batteries was delayed because of dendrite formation on the surface of the lithium electrode, and the difficulty finding a suitable electrolyte that has both the mechanical strength and ionic conductivity required for solid electrolytes. Recently, strategies have developed to overcome these difficulties, so that these batteries are currently an option for different applications, including electric cars. In this work, we review these strategies, and discuss the different routes that are promising for progress in the near future.

Challenges and Issues Facing Lithium Metal for Solid State Rechargeable Batteries

Lithium intercalation compounds are known to form complexes as electron donor systems. A charge transfer which can strongly affect the electronic properties of the host lattice, and a change of preferential crystallographic parameters without destruction of the original structure are the main effects occurring during intercalation. Optical spectroscopies such as Raman scattering, far-infrared reflectivity, absorption measurements, and photoluminescence have been carried out for the study of electronic and structural modification. In this paper, lattice dynamics and physico-chemical properties of various two-dimensional intercalated compounds, i.e. transition metal dichalcogenides, non-transition metal chalcogenides and layered oxides, are presented. Results are discussed with the aim of a better understanding of the intercalation process. Some guide lines are established for improving the performances of these materials in their most eminent applications.

Physical Chemistry of Lithium Intercalation Compounds

Sonochemically synthesized nanostructured ternary electrode material for coin-cell-type supercapacitor applications

We have studied the electrochemical characteristics of Li/MoO 3 -based batteries in relation with the morphology of the cathode-active material. The oxides and oxide-hydrates of molybdenum have been prepared with various degrees of heat treatement. The samples were characterized by X-ray diffraction, Raman spectroscopy, and conductivity measurements. The effect of the heat treatment on structural, optical and electrochemical properties are presented in this work. Thermodynamics and kinetics of lithium insertion were studied in MoO 3 cathodes. Diffusion coefficients and enhancement factors were calculated as functions of the degree of lithium intercalation in the domain of the galvanic cell reversibility.

Christian M. Julien

Papers

Intercalation Compounds for Energy Storage

Challenges and Issues Facing Lithium Metal for Solid State Rechargeable Batteries

Physical Chemistry of Lithium Intercalation Compounds

Sonochemically synthesized nanostructured ternary electrode material for coin-cell-type supercapacitor applications

Effect of the Heat Treatment on the Lithium Insertion Process in MoO3