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

Optical and electrical properties of ternary compounds in the Ag-Ga-Te system are reported. Vibrational properties of AgGaTe2 and AgGa5Te8 single crystals were studied using Raman scattering and infrared absorption spectroscopy. Long-wavelength spectra are analysed and the symmetry of lattice modes are reported. The semiconducting character of Ag-Ga-Te compounds is confirmed by conductivity measurements.

Characterization of the ternary compounds AgGaTe2 and AgGa5Te8

Recent trends in silicon/graphene nanocomposite anodes for lithium-ion batteries

The growth of V2O5 flash-evaporated films

This research sheds light on the intriguing phenomena of structural transformations that take place in spinel LiMn2O4 (space group Fd3m) when charged to high anodic potentials (4.3 to 5.1 V) in lithium cells. It was established from the XRD and electron diffraction analyses that the orthorhombic o-LiMnO2 (space group Pnma) is formed due to the partial transformation of spinel starting at 4.7 V. The Raman spectroscopy measurements of the LiMn2O4 samples charged to 5.1 V also provided evidence of o-LiMnO2, although its band overlaps with the delithiated spinel species. An additional important finding is that some layered-type LiMnO2 is formed upon cycling of the spinel material to 4.5 V, even upon the first charge. LiMnO2 exists as a stable component of the solid electrolyte interphase developed on these electrodes. We also concluded the formation of the layered LiMnO2 structure via solid-state 7Li NMR. The analysis of those results further indicated that the onset of the creation of the intermediate spinel...

Christian M. Julien

Papers

Characterization of the ternary compounds AgGaTe2 and AgGa5Te8

Recent trends in silicon/graphene nanocomposite anodes for lithium-ion batteries

The growth of V2O5 flash-evaporated films

Studies of Spinel-to-Layered Structural Transformations in LiMn2O4 Electrodes Charged to High Voltages

Electrodeposition of Zr on graphite in molten fluorides