Hanyang University

About: Hanyang University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Thin film & Population. The organization has 29387 authors who have published 58815 publications receiving 1190144 citations. The organization is also known as: Hanyang Taehakkyo.

Extracting maximum capacity from Ni-rich Li[Ni0.95Co0.025Mn0.025]O2 cathodes for high-energy-density lithium-ion batteries

Abstract: The electrochemical properties of Li[Ni0.95Co0.025Mn0.025]O2, the composition of which is similar to that of LiNiO2, were evaluated to test whether the beneficial effect of Co and Mn addition persists at this extremely Ni-rich layered Li[NixCoyMn1−x−y]O2 (NCM) cathode. Despite their low concentrations, the presence of Co and Mn ions notably improved the cycling and thermal stability of Li[Ni0.95Co0.025Mn0.025]O2 over that of LiNiO2 (initial discharge capacity of 238 mA h g−1 with 85% retention after 100 cycles when cycled at 4.3 V for Li[Ni0.95Co0.025Mn0.025]O2vs. 248 mA h g−1 but with 74% retention for LiNiO2). It was also shown that the capacity degradation of highly Ni-enriched NCM cathodes appears to arise from the anisotropic volume change during Li removal/insertion, which was aggravated by the formation of the H3 phase in the delithiated state. The particle core was especially susceptible to structural damage from the accumulation of the intrinsic internal strain, which led to the initiation and propagation of microcracks from the particle core. The microcracks subsequently exposed the particle core to electrolyte damage for a prolonged period in the delithiated state, leading to eventual disintegration of the secondary particles. It appears that protecting the particle core (or interparticle boundaries) may help in extending the cycling stability of Ni-rich NCM cathodes, especially for those with very high Ni compositions.

Top Management Ethical Leadership and Firm Performance: Mediating Role of Ethical and Procedural Justice Climate

Abstract: Despite the prevailing discourses on the importance of top management ethical leadership, related theoretical and empirical developments are lacking. Drawing on institutional theory, we propose that top management ethical leadership contributes to organizational outcomes by promoting firm-level ethical and procedural justice climates. This theoretical framework was empirically tested using multi-source data obtained from 4,468 employees of 147 Korean companies from various industries. The firm-level analysis shows that top management ethical leadership significantly predicts ethical climate, which then results in procedural justice climate that fully mediates the effects of top management ethical leadership on two organizational outcomes, namely, firm-level organizational citizenship behavior and firm financial performance. The present study provides a plausible theoretical account and empirical validation of a mechanism through which top management ethical leadership enhances organizational performance.

Variations of formaldehyde and VOC levels during 3 years in new and older homes.

Abstract: UNLABELLED Indoor air organic compounds were continuously monitored during 3 years in new and older homes which were voluntarily selected throughout countries. The levels of volatile organic compounds (VOCs) in the new homes decreased markedly after 1 year, and steady emissions of VOCs were obtained in the initial months. Formaldehyde and a-pinene related to wooden materials need a longer flushing period than the other compounds in the new homes. The levels of the indoor air organic compounds in the older homes showed no significant fluctuation during the 3-year period. Decreases of the indoor-produced compounds in the new homes did not depend upon the ventilation systems. The results indicate that the indoor-produced compounds in the new homes will be more influenced by the aging decreases of emission source strengths than ventilation systems. The quantitative information on the trend of the indoor air organic compound levels will be useful for the risk assessment of indoor exposure to those compounds, and also for Japanese IAQ guidelines. PRACTICAL IMPLICATIONS The initial levels of VOCs in the new homes decreased dramatically and were close to the mean values for the older homes after one year. The results suggest that steady emissions of VOCs are obtained within initial months. However, formaldehyde and a-pinene did not follow the trend for VOCs, particularly in the wooden framed houses. The results tend to suggest that formaldehyde and a-pinene related to wooden materials will need more long a flushing period than other compounds in the new homes. Decreasing tendency of indoor air organic compound levels in the new homes did not appear to show any dependency upon the ventilation systems over the whole period. Absence of data for ventilation rates in the houses dose not permit interpretation of the relation between ventilation rates and indoor air organic compound levels with statistical certainty, but the results suggest that indoor air organic compound levels in the homes will be more influenced by emission source strengths than ventilation systems. The levels of indoor air organic compounds in the new homes are sufficiently decreased according to the ageing decreases of organic compounds when the home is ventilated with adequate quantities.