문준영 교수

An organic redox flow battery adopting tris(2,2'-bipyridine)nickel(II)tetrafluoroborate (Ni(Bpy)3(BF4)2) and tris(2,2'-bipyridine)iron(II)tetrafluoroborate (Fe(BPy)3(BF4)2)) in propylenecarbonate electrolyte is investigated. With cyclic voltammetry, the redox current of one-electron related Fe(II)/Fe(III) and two-electron related Ni(II)/Ni(0) appears at 0.65 V and −1.66 V (vs. Ag/Ag+), respectively and their cycleabilities are highly stable during 100 cycles. Their charge-discharge characteristi

Low-temperature performance of the rechargeable batteries is limited because of a narrow temperature range of the electrolyte. Despite the aqueous electrolyte having a lower freezing point than the ethelyenecarbonate for conventional lithium-ion batteries, its freezing point is as high as 0 °C. Antifreeze additive of ethylene glycol for aqueous electrolyte solutions is used to improve the low-temperature performance of aqueous rechargeable lithium-ion batteries. The suitable contents of ethylene

For high rate capability and energy density of lithium ion batteries, over-lithiated layered cathodes coated by multiwall carbon nanotube were prepared by a novel dry method without decay in the structure.

A bismuth oxide electrode, delivering high capacity, as an anode material for sodium-ion batteries was simply prepared.

A comparative study is made on the surface film formation on the high-voltage LiNi0.5Mn1.5O4 positive electrode at elevated temperature (55°C) in two different electrolytes; LiPF6/organic carbonate and LiTFSI/ionic liquid (propylmethylpyrrolidinium bis(trifluoromethylsulfonyl)imide, PMPyr-TFSI). The surface film derived by a decomposition of the former electrolyte is enriched by inorganic fluorinated species, which becomes thicker with cycling to lead a continued electrode polarization and cell

A breakthrough utilizing an anionic redox reaction (O^2-/O^n-) for charge compensation has led to the development of high-energy cathode materials in sodium-ion batteries. However, its reaction results in a large voltage hysteresis due to the structural degradation arising from an oxygen loss. Herein, an interesting P2-type Mn-based compound exhibits a distinct two-phase behavior preserving a high-potential anionic redox (≈4.2 V vs Na⁺/Na) even during the subsequen

Abstract The issue of the safety of Li‐ion batteries is becoming more critical with the increase in their size for applications in large energy storage devices, such as hybrid electric vehicles (HEVs), and energy storage systems (ESSs) for smart grids. The thermal runaway of Li‐ion batteries is considered to be caused by their flammable components, such as the volatile carbonate solvents of electrolytes. Room temperature ionic liquids (RTILs) have recently received much attention because of thei

The corrosion behavior of Al foil as the current collector for lithium-ion batteries is studied by linear-sweep thermammetry. The onset temperature for Al pitting corrosion depends on Li salt that is dissolved in an ionic liquid solvent; lithium bis(trifluoromethanesulfonyl)imide . With , no corrosion current is observed until . X-ray photoelectron spectroscopy study reveals that this Al surface is covered by Al–F compound (presumably ). Due to the formation of a highly passivating layer in this