Yong-Tae Kim

The cycling performances of lithium–sulfur batteries in TEGDME/DOL containing LiNO3 additive

The cycling performance of lithium–sulfur batteries in binary electrolytes based on tetra(ethylene glycol)dimethyl ether (TEGDME) and 1,3-dioxolane(DOL) with lithium nitrate (LiNO3) additive were investigated. The highest ionic conductivity was obtained for 1xa0M LiN(CF3SO2)2 (LiTFSI) in TEGDME/DOLu2009=u200933:67(volume ratio)-based electrolyte. The cyclic efficiency of lithium–sulfur batteries was dramatically increased with LiNO3 additive as a shuttle inhibitor in electrolytes. The lithium–sulfur cell assembled with 1xa0M LiTFSI in TEGDME/DOL containing 0.2xa0M LiNO3 additive for electrolyte, the elemental sulfur for cathode, and the lithium metal for anode demonstrated the initial discharge capacity of about 900xa0mAhxa0g−1 and an enhanced cycling performance.

Evaluation of the formability of a bipolar plate manufactured from aluminum alloy Al 1050 using the rubber pad forming process

The rubber pad forming process has been used to fabricate metallic bipolar plates from aluminum 1050 alloy for use in a proton-exchange membrane fuel cell. The plates were fabricated using a 200 ton hydraulic press and the effects of the process parameters of the rubber pad forming process (plate thickness, punch speed, press pressure, rubber thickness and rubber hardness) on the forming depth and thinning were evaluated.

Mn valence state and electrode performance of perovskite-type cathode La0·8Sr0·2Mn1 − xCuxO3 − δ (x = 0, 0·2) for intermediate-temperature solid oxide fuel cells

Cu-free and Cu-doped LSM system, La0·8Sr0·2Mn1u2009−u2009xCuxO3u2009−u2009δ(xu2009=u20090, 0·2), with perovskite structure were prepared using an EDTA combined citrate process and the effects of Cu ion at B-site were investigated. Electrical conductivity and polarization resistance of the Cu-doped LSM were 210 S·cmu2009−u20091 at 750 °C, and 2·54 Ω · cm2 at 800 °C, respectively which were better than those of the Cu-free LSM. This indicated that the electrode performance of LSM was improved by the addition of Cu. The oxidation state of Mn ions increased with addition of Cu. The increase in the oxidation state of Mn ions was due to the formation of Mn4u2009+u2009 ions and oxygen vacancies. The addition of Cu ions to LSM systems could lead to enhanced electrode performance for oxygen reduction reactions originating from the change in valence of Mn ions.