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

III–VI compounds such as InSe, GaSe or In2Se3 are layered semiconductors and are intercalated with lithium or silver by spontaneous reaction in n-butyllithium and an electrochemical process. These compounds appear to be good hosts for the insertion of Li at room temperature and Li intercalated InSe has been shown to function as a cathode in Li solid state batteries.

Electrical and Optical Properties of Intercalated In-Se Layered Materials

Optimized LiFePO4 positive electrode for Li-ion batteries was obtained after severe control of the fundamental properties of material. The nanoscopic structure and magnetic properties of a series of carbon-coated LiFePO4 particles prepared under various conditions were analyzed with XRD, FTIR, Raman and SQUID magnetometry. We evaluate intrinsic and extrinsic properties. The existence of low content of nano-sized ferromagnetic particles was evidenced by magnetic measurements in samples grown from iron(II) oxalate; such ferromagnetic clusters do not exist in the optimised samples grown from FePO4(H2O)2. Other impurity phases such as Fe2P, Li3Fe2(PO4)3, FeP2O7 were also detected for particular conditions of preparation. The impact of the carbon coating on the electrochemical properties is reported. Li-ion cells show excellent cyclability after 200 cycles at 60 °C without iron dissolution.

High Performance of Lithium Iron Phosphates for HEV with Quality Control Made by Magnetometry

Advanced silicon-based electrodes for high-energy lithium-ion batteries

Bimetal–organic frameworks (BMOFs) have attracted considerable attention as electrode materials for energy storage devices because of the precise control of their porous structure, surface area, and pore volume. BMOFs can promote multiple redox reactions because of the enhanced charge transfer between different metal ions. Therefore, the electroactivity of the electrodes can be significantly improved. Herein, we report a NiCo-MOF (NCMF) with a three-dimensional hierarchical nanorod-like structure prepared using a facile solvo-hydrothermal method. The as-prepared NCMF was used as the positive electrode in a hybrid pouch-type asymmetric supercapacitor device (HPASD) with a gel electrolyte (KOH+PVA) and activated carbon as the negative electrode. Because of the matchable potential windows and specific capacitances of the two electrodes, the assembled HPASD exhibits a specific capacitance of 161 F·g−1 at 0.5 A·g−1, an energy density of 50.3 Wh·kg−1 at a power density of 375 W·kg−1, and a cycling stability of 87.6% after 6000 cycles. The reported unique synthesis strategy is promising for producing high-energy-density electrode materials for supercapacitors.

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Christian M. Julien

Papers

Electrical and Optical Properties of Intercalated In-Se Layered Materials

High Performance of Lithium Iron Phosphates for HEV with Quality Control Made by Magnetometry

Advanced silicon-based electrodes for high-energy lithium-ion batteries

Pouch-Type Asymmetric Supercapacitor Based on Nickel–Cobalt Metal–Organic Framework

Characterization of LiFePO4 at Nanoscopic Scale in Relation to the Mode of Preparation