Publications by authors named "Kang-Seop Yun"

We propose the ReaxFF reactive force field as a simulation protocol for predicting the evolution of solid-electrolyte interphase (SEI) components such as gases (CH, CO, CO, CH, and CH), and inorganic (LiCO, LiO, and LiF) and organic (ROLi and ROCOLi: R = -CH or -CH) products that are generated by the chemical reactions between the anodes and liquid electrolytes. ReaxFF was developed from ab initio results, and a molecular dynamics simulation with ReaxFF realized the prediction of SEI formation under real experimental conditions and with a reasonable computational cost. We report the effects on SEI formation of different kinds of Si anodes (pristine Si and SiO), of the different types and compositions of various carbonate electrolytes, and of the additives.

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A SiO x coating material for Si anode in lithium-ion battery was processed by using SiCl4 and ethylene glycol. The produced SiO x particles after heat treatment at 725°C for 1 h were porous and irregularly shaped with amorphous structure. Pitch carbon added to SiO x was found to strongly affect solid electrolyte interphase stabilization and cyclic stability.

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The effect of TiO2 layer applied to the conventional Fe2O3/FTO photoanode to improve the photoelectrochemical performance was assessed from the viewpoint of the microstructure and energy band structure. Regardless of the location of the TiO2 layer in the photoanodes, that is, Fe2O3/TiO2/FTO or TiO2/Fe2O3/FTO, high performance was obtained when α-Fe2O3 and H-TiNT/anatase-TiO2 phases existed in the constituent Fe2O3 and TiO2 layers after optimized heat treatments. The presence of the Fe2O3 nanoparticles with high uniformity in the each layer of the Fe2O3/TiO2/FTO photoanode achieved by a simple dipping process seemed to positively affect the performance improvement by modifying the energy band structure to a more favorable one for efficient electrons transfer.

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In this study, carbon black nanoparticles were synthesized by Liquid Phase Plasma (LPP) technique; plasma generated in the organic solvent of benzene at 4.9 kV with the pulse frequency of 15 kHz and width of 5 micros transformed the carbon atoms in the solvent into carbon blacks by oxidation and reduction reactions. Graphite phase was found to be introduced into the carbon blacks without any additional processes due to the characteristics of LPP process, resulting in a higher G/D ratio of 0.

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Background: Belt or wire shaped TiO2(B) particles were synthesized for lithium ion battery application by a hydrothermal and heat treatment process. In order to facilitate TiO2(B)/C composites fabrication, the synthesized TiO2(B) particles were crushed into smaller sizes by ball milling.

Results: Ball mill treated TiO2(B) particles of less than 1.

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