Hyun‐Kon Song 교수

Abstract Application targets of lithium ion batteries (LIBs) are moving from small‐sized mobile devices of information technology to large‐scale electric vehicles (xEVs) and energy storage systems (ESSs). Environmental issues and abruptly increasing power demands are pushing high performance energy storage devices or systems onto markets. LIBs are one of the most potential candidates as the energy storage devices mainly due to their high energy densities with fairly good rate capabilities and a

Lithium iron phosphate olivine (LFP) and lithium manganese oxide spinel (LMO) are competitive and complementary to each other as cathode materials for lithium ion batteries, especially for use in hybrid electric vehicles and electric vehicles. Interest in these materials, due to their low cost and high safety, has pushed research and development forward and toward high performance in terms of rate capability and capacity retention or cyclability at a high temperature of around 60 °C. From the vi

A gel polymer electrolyte (GPE) is a liquid electrolyte (LE) entrapped by a small amount of polymer network less than several wt%, which is characterized by properties between those of liquid and solid electrolytes in terms of the ionic conductivity and physical phase. Electrolyte leakage and flammability, demerits of liquid electrolytes, can be mitigated by using GPEs in electrochemical cells. However, the contact problems between GPEs and porous electrodes are challenging because it is difficu

Abstract Diversified and extended applications of lithium‐ion batteries demand the development of more enhanced materials that can be achieved by sophisticated synthetic methods. Combination of novel materials with strategic design of their shape on the nanometer scale enables a breakthrough to overcome problems experienced by present technologies. In this feature article, an overview is given of Mn‐based and polyanion‐based cathode materials with nanoscale features for lithium‐ion batteries as

An energy-storage device consisting of polypyrrole (pPy) doped with indigo carmine (IC) and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonate) (ABTS) has been fabricated. These redox-active conducting polymers (see figure) form the basis of a battery that depends on the faradaic reactions of the redox-active dopants, and performs better than conventional batteries and ultracapacitors at high power density. Supporting information for this article is available on the WWW under http://www.wiley-vch

A facile approach to the surface modification of spinel LiNi0.5Mn1.5O4 (LNMO) cathode active materials for high-voltage lithium ion batteries is demonstrated. This strategy is based on nanoarchitectured polyimide (PI) gel polymer electrolyte (GPE) coating. The PI coating layer successfully wrapped a large area of the LNMO surface via thermal imidization of 4-component (pyromellitic dianhydride/biphenyl dianhydride/phenylenediamine/oxydianiline) polyamic acid. In comparison to conventional metal

Succinonitrile (SN, CN–[CH2]2–CN) is evaluated as an additive for improving thermal stability in ethylene carbonate (EC)-based electrolytes for lithium ion batteries. Without any sacrifice of performance such as cyclability and capacity, the introduction of SN into an electrolyte with a graphite anode and LixCoO2 cathode leads to (1) reducing the amount of gas emitted at high temperature, (2) increasing the onset temperature of exothermic reactions and (3) decreasing the amount of exothermal hea

Lithium ion movement was accelerated by enlarging the interlayer distance of graphite as well as by polarizing its surface charge. As a result, the rate performances of lithium ion batteries were significantly enhanced.

We report on the evolution of a hollow sphere secondary structure of spherical nanoparticles by a solubilization-reprecipitation mechanism based on the difference of solubility products (K(sp)) of two different precipitates. Carbon-coated nanoparticles of olivine structure LiFePO(4) served as the primary nano-blocks to build the secondary nano-architecture.

Wireless communication: Platinum nanoparticles (nPt) in an electrolyte enhance electron transfer from the electrode to NAD+ during the indirect electrochemical regeneration of NADH (see picture). The intermediate nPt-Hads, formed at negative potential, helps the turnover of the primary mediator M by donating a proton and an electron in a kinetically favorable way. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2008/z703632_s.pdf or