• 한국수소및신에너지학회논문집
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• 제5권1호
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• pp.33-39
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• 1994

The changes of hydrogenation properties of $LaNi_5$ by hydrogen charging condition were investigated using the P-C-isotherm curves, DSC(Differential Scanning Calorimetry), GC(Gas Chromatograph), X-ray diffractometer. As a results of static hydrogen charging, the hydrogen storage capacity gradually decreased and the plateau region severly slopped. Most of the degraded properties could be restored by the annealing treatment. The degradation of hydrogen storage capacity was related with the formation of stable hydride, which was not dehydrided at room temperature.

• 한국수소및신에너지학회논문집
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• 제19권3호
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• pp.248-259
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• 2008

There are several well-known materials for the hydrogen storage such as metallic alloy, carbon nanomaterials, non-carbon nanomaterials, and compounds etc. Efficient and inexpensive hydrogen storage methods are an essential prerequisite for the utilization of hydrogen, one of the new and clean energy sources. Many researches have been widely performed for the hydrogen storage techniques and materials to improve the high storage capacity and stability. In this paper, the patents concerning the non-carbon nanomaterial hydrogen storage method were collected and analyzed. The search range was limited in the open patents of Korea(KR), Japan(JP), USA(US) and European Union(EP) from 1996 to 2007. Patents were collected by using key-words searching and filtered by filtering criteria. The trends of the patents was analyzed by the years, countries, companies. and technologies.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2005년도 수소연료전지공동심포지움 2005논문집
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• pp.329-334
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• 2005

In order to find out rational design and synthetic strategies toward efficient hydrogen storage materials, we performed quantum mechanical calculations on a series of the Metal-Organic Frameworks (MOFs) containing functionalized organic linkers. Based on the shape of frontier orbitals and the electrostatic potential map of various MOFs from density functional theory calculations, it was found that the delocalization of electron and asymmetric polarization of the organic linker play an important role in the hydrogen storage capacity of Metal-Organic Frameworks. The prediction of the modeling study could be supported by the hydrogen adsorption experiments using MOF-5 and amine substituted MOF-5, which showed more enhanced hydrogen storage capacity of amine substituted MOF-5 compared with that of MOF-5.

• 한국수소및신에너지학회논문집
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• 제12권3호
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• pp.177-189
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• 2001

T hydrogen absorption-desorption behavior induced by thermal or hydrogen pressure cycling in a closed system was observed in hydrogen storage alloys, $(La-R-Mm)Ni_{4.5}Fe_{0.5}$, $MmNi_4Fe_{0.85}Cu_{0.15}$ and $(Ce-F-Mm)Ni_{4.7}Al_{0.2}Fe_{0.1}$. Thereby (La-R-Mm), Mm and (Ce-F-Mm) refer to La-rich mischmetal, mischmetal and Ce-free mischmetal respectively. As the results, it is found that the alloy stabilities during thermal cycling varies with alloy composition change. The highest stability occurs in $MmNi_4Fe_{0.85}Cu_{0.15}$ and the lowest stability in $(La-R-Mm)Ni_{4.5}Fe_{0.5}$. Comparing hydrogen pressure cycling with thermal cycling, pressure cycling causes severer degradation of the alloy $(Ce-F-Mm)Ni_{4.7}Al_{0.2}Fe_{0.1}$ than thermal cycling. When the 1500 times-cycled alloy is annealed at $400^{\circ}C$ for 3hrs under 1 atm of hydrogen pressure the hydrogen storage capacity is recovered only partially but not completely to the initial capacity. The amount of capacity loss after annealing is larger in the hydrogen pressure cycled samples than in the thermal cycled, suggesting an incoming of impure gas during hydrogen pressure cycling.

• 한국수소및신에너지학회논문집
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• 제17권1호
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• pp.47-54
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• 2006

Activated carbon fibers (ACFs) with high surface area and pore volume were modified with metal Ni impregnation and fluorination and investigated hydrogen storage properties by volumetric method. Micropore volume values of ACFs obtained from surface modification with Ni impregnation and fluorination were decreased 9 and 35 %, respectively. Hydrogen storage capacities of fluorinated ACFs were slightly changed, on the other hand, that of Ni impregnated ACF was considerably increased. It means that hydrogen was not only adsorbed on ACF surface, but also on Ni metal surface by means of dissociation. Although the microphone volume of ACF modified with fluorination was decreased, its hydrogen storage were found not to be changed compared with fresh ACF. These results indicated that the surface of ACF after fluorination modification may be strongly attracted hydrogen due to high electronegativity of fluorine. Therefore, it was proven that hydrogen storage capacity was related with micropore volume and surface property of carbon materials as well as specific surface area.

• 한국재료학회지
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• 제22권3호
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• pp.159-167
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• 2012

Hydrogen is in the spotlight as an alternative next generation energy source for the replacement of fossil fuels because it has high specific energy density and emits almost no pollution, with zero $CO_2$ emission. In order to use hydrogen safely, reliable storage and transportation methods are required. Recently, solid hydrogen storage systems using metal hydrides have been under extensive development for application to fuel cell vehicles and fuel cells of MCFC and SOFC. For the practical use of hydrogen on a commercial basis, hydrogen storage materials should satisfy several requirements such as 1) hydrogen storage capacity of more than 6.5wt.% $H_2$, moderate hydrogen release temperature below $100^{\circ}C$, 3) cyclic reversibility of hydrogen absorption/desorption, 4) non toxicity and low price. Among the candidate materials, Li based metal hydrides are known to be promising materials with high practical potential in view of the above requirements. This paper reviews the characteristics and recent R&D trends of Li based complex hydrides, Li-alanates, Li-borohydrides, and Li-amides/imides.

• 공업화학
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• 제18권2호
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• pp.99-110
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• 2007

21세기의 새로운 청정 에너지원으로 각광받고 있는 수소의 성공적인 활용을 위해 높은 저장 용량을 갖는 수소 저장체와 효과적인 수소 저장기술의 개발이 필요하다. 본 총설에서는 다양한 수소 저장 방법에 대해 간략히 요약하고 그 가운데 나노세공체를 이용한 저온 물리흡착에 의한 수소 저장기술의 현황에 대해 살펴보았다. 기존에 알려져 있는 고압의 압축 저장기술과 상온 고압의 수소저장 물질의 개발 이외에도 최근에는 높은 표면적과 큰 세공 부피를 갖는 나노세공체를 이용한 저온 물리흡착 방식이 개발 가능한 수소의 저장 기술의 하나로 활발히 연구되고 있다. 본 총설에서는 높은 수소 저장 용량을 위해 필요한 나노세공체의 특성을 요약하였으며 높은 표면적 및 미세 세공부피, 작은 세공 크기, 큰 정전기장 및 불포화 배위자리가 필요함을 알 수 있었다. 최근까지 보고된 나노세공체 흡착제에 의한 수소 저장 능력을 정리하였는데 현재까지 보고된 최고의 결과로는 액체 질소 온도($-196^{\circ}C$)의 약 80 기압에서 약 7.5wt%의 수소를 저장할 수 있다고 알려져 있다. 향후 지속적이고 새로운 나노세공체의 설계, 합성, 제조 및 수식에 대한 노력을 통해 수소에너지 저장에 활용될 수 있는 효과적인 수소 저장체 개발을 기대한다.

• 한국수소및신에너지학회논문집
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• 제28권4호
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• pp.361-368
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• 2017

Alanate-based materials, which were known to have high hydrogen storage capacity, were synthesized by mechanochemically metathesis reaction of metal chloride and sodium alanate without solvent. XRD patterns of synthesized materials showed that metathesis reaction of cations between metal chloride and sodium alanate was progressed favorably without any solvent. Magnesium alanate showed that 3.2 wt.% of hydrogen was evolved by the thermal decomposition. The addition of a small amount of Ti to the magnesium alanate greatly reduced hydrogen evolution temperature. Also, Ti doped magnesium alanate had a good regeneration property. Both the calcium and lithium-magnesium alanate showed the lower starting temperature of the two step hydrogen evolution and fast kinetics for the hydrogen evolution.

• 한국재료학회지
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• 제20권10호
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• pp.543-549
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• 2010

The hydrogen energy had recognized clean and high efficiency energy source. The research field of hydrogen energy was production, storage, application and transport. The commercial storage method was using high pressure tanks but it was not safety. However metal hydride was very safety due to high chemical stability. Mg and Mg alloys are attractive as hydrogen storage materials because of their lightweight and high absorption capacity (about 7.6 wt%). Their range of applications could be further extended if their hydrogenation properties and degradation behavior could be improved. The main emphasis of this study was to find an economical manufacturing method for Mg-Ti-Ni-H systems, and to investigate their hydrogenation properties. In order to examine their hydrogenation behavior, a Sievert's type automatic pressure-compositionisotherm (PCI) apparatus was used and experiments were performed at 423, 473, 523, 573, 623 and 673 K. The results of the thermogravimetric analysis (TGA) revealed that the absorbed hydrogen contents were around 2.5wt.% for (Mg8Ti2)-10 wt.%Ni. With an increasing Ni content, the absorbed hydrogen content decreased to 1.7 wt%, whereas the dehydriding starting temperatures were lowered by some 70-100 K. The results of PCI on (Mg8Ti2)-20 wt.%Ni showed that its hydrogen capacity was around 5.5 wt% and its reversible capacity and plateau pressure were also excellent at 623 K and 673 K.

• 한국수소및신에너지학회논문집
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• 제33권3호
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• pp.247-254
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• 2022

Slush hydrogen containing liquid and solid hydrogen is expected to achieve zero boil-off by suppressing boil-off gas because heat of fusion for solid absorbe the heat ingress from atmosphere. In this paper, quantitative analysis on storage cost considering specific energy consumption between 1,000 m³ class liquid hydrogen storage system with re-liquefaction and slush hydrogen storage system during equivalent zero boil off period. Even though approximately 50% of total storage capacity should be converted into solid phase during the initial cargo bunkering, total energy consumption to convert into slush hydrogen is relatively 25% less than re-liquefaction energy for boil off hydrogen during zero boil off period. That's because energy consumption of slush phase change take up only 1.8% of liquefaction energy. moreover, annual revenue requirement including CAPEX, OPEX and electric cost for slush hydrogen storage could be more reduced approximately 32.5% than those of liquid hydrogen storage and specific energy storage cost ($/kg-H₂) could also be lowered by about 41.7% compared with liquid hydrogen storage.