Park Minsik

Long and thin: SnO2 nanowires with tetragonal structure were successfully synthesized by a thermal evaporation method without any conventional metal catalysts. The enhanced electrochemical performance of SnO2 nanowires is believed to result from the combination of unique nanostructures with a high length/diameter ratio and the absence of traditional metal catalysts.

The vanadium redox flow battery, which was first suggested by Skyllas-Kazacos and co-workers in 1985, is an electrochemical storage system which allows energy to be stored in two solutions containing different redox couples.

Lithium metal has shown a lot of promise for use as an anode material in rechargeable batteries owing to its high theoretical capacity. However, it does not meet the cycle life and safety requirements of rechargeable batteries owing to electrolyte decomposition and dendrite formation on the surfaces of the lithium anodes during electrochemical cycling. Here, we propose a novel electrolyte system that is relatively stable against lithium metal and mitigates dendritic growth. Systematic design met

A structured SnO2–reduced graphene oxide (RGO) nanocomposite has been synthesized with SnO2 nanoparticles (∼5 nm) anchored on a RGO framework. It has been successfully applied as an anode material in sodium-ion batteries. The electrode delivers a reversible Na-storage capacity of 330 mA h g−1 with an outstanding capacity retention of 81.3% over 150 cycles. Moreover, it possesses a relatively good rate capability, exhibiting a capacity retention of 25.8% at high rate (1000 mA h g−1). With its com

Lang und schmal: Tetragonale SnO2-Nanodrähte wurden durch thermische Verdampfung ohne Zusatz von Metallkatalysatoren synthetisiert. Die verbesserten elektrochemischen Eigenschaften dieser Nanodrähte resultieren vermutlich aus dem außergewöhnlich großen Aspektverhältnis und der Abwesenheit von Metallverunreinigungen. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2001/2007/z603309_s.pdf or from the author. Please note: The publisher is no

Silicon-based materials are the most promising candidates to surpass the capacity limitation of conventional graphite anode for lithium ion batteries. Unfortunately, Si-based materials suffer from poor cycling performance and dimensional instability induced by the large volume changes during cycling. To resolve such problems, nanostructured silicon-based materials with delicately controlled microstructure and interfaces have been intensively investigated. Nevertheless, they still face problems r

A practical route is introduced for synthesizing a sulfur-impregnated graphene composite as a promising cathode material for lithium-sulfur batteries. Sulfur particles with a size of a few microns are successfully grown in the interior spaces between randomly dispersed graphene sheets through a heterogeneous crystal growth mechanism. The proposed route not only enables the control of the particle size of active sulfur but also affords quantitative yields of composite powder in large quantities.

We have investigated electronic structures and magnetic properties of ZnO-based potential diluted magnetic semiconductors codoped with transition metals: ${\mathrm{Zn}}_{1\ensuremath{-}x}(\mathrm{FeCo}{)}_{x}\mathrm{O}$ and ${\mathrm{Zn}}_{1\ensuremath{-}x}(\mathrm{FeCu}{)}_{x}\mathrm{O}.$ We have found that the origin of the observed ferromagnetism in ${\mathrm{Zn}}_{1\ensuremath{-}x}(\mathrm{FeCo}{)}_{x}\mathrm{O}$ would be different from that in ${\mathrm{Zn}}_{1\ensuremath{-}x}(\mathrm{FeCu}

Transition metal oxides possessing two kinds of metals (denoted as AxB3-xO4, which is generally defined as a spinel structure; A, B = Co, Ni, Zn, Mn, Fe, etc.), with stoichiometric or even non-stoichiometric compositions, have recently attracted great interest in electrochemical energy storage systems (ESSs). The spinel-type transition metal oxides exhibit outstanding electrochemical activity and stability, and thus, they can play a key role in realising cost-effective and environmentally friend

We have investigated electronic structures of a room-temperature-diluted magnetic semiconductor: Co-doped anatase ${\mathrm{TiO}}_{2}.$ We have obtained the half-metallic ground state in the local-spin-density approximation (LSDA) and the insulating ground state in the $\mathrm{LSDA}+U+\mathrm{SO}$ incorporating the spin-orbit interaction. In the stoichiometric case, the low spin state of Co is realized with the substantially large orbital moment. However, in the presence of oxygen vacancies nea

Lithium–air battery (LAB) technology is currently being considered as a future technology for resolving energy and environmental issues. Here, we introduce recent advances and the remaining technical challenges in the development of LABs, particularly focusing on the cathodes based on a fundamental understanding of Li–O₂electrochemistry.