• Title/Summary/Keyword: Structural materials

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Research Trends of Cathode Materials for Lithium-Ion Batteries used in Electric Vehicles (전기자동차용 리튬이온전지를 위한 양극전극 분말 재료의 연구 동향)

  • Shin, Dong-Yo;Ahn, Hyo-Jin
    • Journal of Powder Materials
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    • v.26 no.1
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    • pp.58-69
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    • 2019
  • High performance lithium-ion batteries (LIBs) have attracted considerable attention as essential energy sources for high-technology electrical devices such as electrical vehicles, unmanned drones, uninterruptible power supply, and artificial intelligence robots because of their high energy density (150-250 Wh/kg), long lifetime (> 500 cycles), low toxicity, and low memory effects. Of the high-performance LIB components, cathode materials have a significant effect on the capacity, lifetime, energy density, power density, and operating conditions of high-performance LIBs. This is because cathode materials have limitations with respect to a lower specific capacity and cycling stability as compared to anode materials. In addition, cathode materials present difficulties when used with LIBs in electric vehicles because of their poor rate performance. Therefore, this study summarizes the structural and electrochemical properties of cathode materials for LIBs used in electric vehicles. In addition, we consider unique strategies to improve their structural and electrochemical properties.

Stability of Zirconium Metal Organic Frameworks with 9,10- Dicarboxylic Acid Anthracene as Ligand

  • Xiao, Sheng-Bao;Chen, Sai-Sai;Liu, Jin;Li, Zhen;Zhang, Feng-Jun;Wang, Xian-Biao;Oh, Won-Chun
    • Journal of the Korean Ceramic Society
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    • v.53 no.2
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    • pp.200-205
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    • 2016
  • With high specific surface area and pore structural diversity, MOFs show important applications in gas storage, catalysis, sensing, separation, and biomedicine. However, the stability of the structure of MOFs has restricted their application and development. In this study, zirconium metal organic frameworks with 9,10-dicarboxylic acid anthracene as ligand, named UIO-66 ($H_2DCA$), were synthesized and their properties and structures were characterized by XRD, SEM, and $N_2$ adsorption. We focus on the stability of the structure of UIO-66 ($H_2DCA$) under different conditions (acid, alkali, and water). The structural changes or ruins of UIO-66 ($H_2DCA$) were traced by means of XRD, TG, and FT-IR under different conditions. The results show that the UIO-66 ($H_2DCA$) materials are stable at 583 K, and that this structural stability is greatly influenced by different types of acid and alkali compounds. Importantly, we found that the structures maintain their stability in environments of nitric acid, triethylamine, and boiling water.

Effects of the structural strength of fire protection insulation systems in offshore installations

  • Park, Dae Kyeom;Kim, Jeong Hwan;Park, Jun Seok;Ha, Yeon Chul;Seo, Jung Kwan
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.13 no.1
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    • pp.493-510
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    • 2021
  • Mineral wool is an insulation material commonly used in passive fire protection (PFP) systems on offshore installations. Insulation materials have only been considered functional materials for thermal analysis in the conventional offshore PFP system design method. Hence, the structural performance of insulation has yet to be considered in the design of PFP systems. However, the structural elements of offshore PFP systems are often designed with excessive dimensions to satisfy structural requirements under external loads such as wind, fire and explosive pressure. To verify the structural contribution of insulation material, it was considered a structural material in this study. A series of material tensile tests was undertaken with two types of mineral wool at room temperature and at elevated temperatures for fire conditions. The mechanical properties were then verified with modified methods, and a database was constructed for application in a series of nonlinear structural and thermal finite-element analyses of an offshore bulkhead-type PFP system. Numerical analyses were performed with a conventional model without insulation and with a new suggested model with insulation. These analyses showed the structural contribution of the insulation in the structural behaviour of the PFP panel. The results suggest the need to consider the structural strength of the insulation material in PFP systems during the structural design step for offshore installations.