Heat and Mass Transfer in Solid State Hydrogen Storage: A Review

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
S. Srinivasa Murthy

Metal hydrides are formed when certain metals or alloys are exposed to hydrogen at favorable temperatures and pressures. In order to sustain the sorption of hydrogen during this exothermic process, the generated heat has to be removed effectively. Release of hydrogen is an endothermic process needing supply of heat to the metal hydride matrix. Depending on the application, the heat transfer medium can be either a liquid or a gas. Reduction of the total weight of hydrogen storage devices is essential toward utilization of hydrogen for mobile and portable applications. While a variety of new storage materials with desirable sorption characteristics are being suggested, optimal thermal design of the storage device remains a major challenge. Lack of thermodynamic, transport, and thermophysical property data of the material particles and of the bed is another drawback which needs to be addressed.

Author(s):  
S. Srinivasa Murthy

Metal hydrides are formed when certain metals or alloys are exposed to hydrogen at favorable temperatures and pressures. In order to sustain the sorption of hydrogen during this exothermic process, the generated heat has to be removed effectively. Release of hydrogen is an endothermic process needing supply of heat to the metal hydride matrix. Depending on the application, the heat transfer medium can be either a liquid or a gas. Reduction of the total weight of hydrogen storage devices is essential towards utilization of hydrogen for mobile and portable applications. While a variety of new storage materials with desirable sorption characteristics are being suggested, optimal thermal design of the storage device remains a major challenge. Lack of thermodynamic, transport and thermophysical property data of the material particles and of the bed is another drawback which needs to be addressed.


Author(s):  
G. Mohan ◽  
M. P. Maiya ◽  
S. Srinivasa Murthy

Determination of the minimum total weight is the main criterion in the design of a solid state hydrogen storage device for mobile or portable applications. The design should address additional requirements such as storage capacity, charge/discharge rates, space constraints, coolant temperature and hydrogen supply pressure. The typical metal hydride based storage device studied here consists of several filters to distribute hydrogen gas, and heat exchanger tubes to cool or heat the hydride bed based on whether hydrogen is absorbed or desorbed. The total weight of the system includes hydrogen storage material, heat exchanger tubes and associated heat transfer media, porous sintered filters and the cylindrical outer container. Systematic simulation of the heat and mass transfer during hydrogen sorption has been carried out for different feasible configurations. LaNi5 is used as the representative hydriding alloy in the device as its sorption performance is limited by heat transfer in the bed. The effect of geometric parameters on total system weight and charging time are plotted at specified operating conditions. These plots are used for the design of hydrogen storage devices with minimum system weight satisfying the imposed constraints.


Author(s):  
T. Schober

Nb, Ta and V are prototype substances for the study of the endothermic reactions of H with metals. Such metal-hydrogen reactions have gained increased importance due to the application of metal-hydrides in hydrogen- und heat storage devices. Electron microscopy and diffraction were demonstrated to be excellent methods in the study of hydride morphologies and structures (1). - Figures 1 and 2 show the NbH and TaH phase diagrams (2,3,4). EM techniques have contributed substantially to the elucidation of the structures and domain configurations of phases β, ζ and ε (1,4). Precision length measurement techniques of distances in reciprocal space (5) recently led to a detailed understanding of the distortions of the unit cells of phases ζ and ε (4). In the same work (4) the existence of the new phase η was shown. It is stable near -68 °C. The sequence of transitions is thus below 70 %.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4000
Author(s):  
Eunhwan Kim ◽  
Juyeon Han ◽  
Seokgyu Ryu ◽  
Youngkyu Choi ◽  
Jeeyoung Yoo

For decades, improvements in electrolytes and electrodes have driven the development of electrochemical energy storage devices. Generally, electrodes and electrolytes should not be developed separately due to the importance of the interaction at their interface. The energy storage ability and safety of energy storage devices are in fact determined by the arrangement of ions and electrons between the electrode and the electrolyte. In this paper, the physicochemical and electrochemical properties of lithium-ion batteries and supercapacitors using ionic liquids (ILs) as an electrolyte are reviewed. Additionally, the energy storage device ILs developed over the last decade are introduced.


2020 ◽  
Vol 10 (3) ◽  
pp. 999
Author(s):  
Hyokyung Bahn ◽  
Kyungwoon Cho

Recently, non-volatile memory (NVM) has advanced as a fast storage medium, and legacy memory subsystems optimized for DRAM (dynamic random access memory) and HDD (hard disk drive) hierarchies need to be revisited. In this article, we explore the memory subsystems that use NVM as an underlying storage device and discuss the challenges and implications of such systems. As storage performance becomes close to DRAM performance, existing memory configurations and I/O (input/output) mechanisms should be reassessed. This article explores the performance of systems with NVM based storage emulated by the RAMDisk under various configurations. Through our measurement study, we make the following findings. (1) We can decrease the main memory size without performance penalties when NVM storage is adopted instead of HDD. (2) For buffer caching to be effective, judicious management techniques like admission control are necessary. (3) Prefetching is not effective in NVM storage. (4) The effect of synchronous I/O and direct I/O in NVM storage is less significant than that in HDD storage. (5) Performance degradation due to the contention of multi-threads is less severe in NVM based storage than in HDD. Based on these observations, we discuss a new PC configuration consisting of small memory and fast storage in comparison with a traditional PC consisting of large memory and slow storage. We show that this new memory-storage configuration can be an alternative solution for ever-growing memory demands and the limited density of DRAM memory. We anticipate that our results will provide directions in system software development in the presence of ever-faster storage devices.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jing Hu ◽  
Xiaomin Tang ◽  
Qing Dai ◽  
Zhiqiang Liu ◽  
Huamin Zhang ◽  
...  

AbstractMembranes with fast and selective ions transport are highly demanded for energy storage devices. Layered double hydroxides (LDHs), bearing uniform interlayer galleries and abundant hydroxyl groups covalently bonded within two-dimensional (2D) host layers, make them superb candidates for high-performance membranes. However, related research on LDHs for ions separation is quite rare, especially the deep-going study on ions transport behavior in LDHs. Here, we report a LDHs-based composite membrane with fast and selective ions transport for flow battery application. The hydroxide ions transport through LDHs via vehicular (standard diffusion) & Grotthuss (proton hopping) mechanisms is uncovered. The LDHs-based membrane enables an alkaline zinc-based flow battery to operate at 200 mA cm−2, along with an energy efficiency of 82.36% for 400 cycles. This study offers an in-depth understanding of ions transport in LDHs and further inspires their applications in other energy-related devices.


2001 ◽  
Vol 676 ◽  
Author(s):  
W. Oelerich ◽  
T. Klassen ◽  
R. Bormann

ABSTRACTHydrogen is the ideal means of energy storage for transportation and conversion of energy in a comprehensive clean-energy concept. However, appropriate storage facilities, both for stationary and for mobile applications, are complicated, because of the very low boiling point of hydrogen (20.4 K at 1 atm) and its low density in the gaseous state (90 g/m3). Furthermore, the storage of hydrogen in liquid or gaseous form imposes safety problems, in particular for mobile applications, e.g. the future zero-emission vehicle. Metal hydrides are a safe alternative for H-storage and, in addition, have a high volumetric energy density that is about 60% higher than that of liquid hydrogen. Mg hydride has a high storage capacity by weight and is therefore favoured for automotive applications. However, so far light metal hydrides have not been considered competitive because of their rather sluggish sorption kinetics. Filling a tank could take several hours. Moreover, the hydrogen desorption temperature of about 300 °C is rather high for most applications. A breakthrough in hydrogen storage technology was achieved by preparing nanocrystalline hydrides using high-energy ball milling. These new materials show very fast aband desorption kinetics within few minutes, thus qualifying lightweight Mg-based hydrides for storage application. In this paper recent detailed results on the sorption behaviour of nanocrystalline Mg and Mg-based alloys are presented. In a following research effort the sorption kinetics of nanocrystalline Mg has been further enhanced by catalyst additions. Furthermore, different transition metals have been added to Mg to achieve a thermodynamic destabilisation of the hydride, thus lowering the desorption temperatures to about 230 °C. The newly developed materials are currently being tested in prototype storage tanks.


Materia Japan ◽  
2013 ◽  
Vol 52 (7) ◽  
pp. 328-332
Author(s):  
Yumiko Nakamura ◽  
Kouji Sakaki ◽  
Kohta Asano ◽  
Hyunjeong Kim ◽  
Itoko Matsumoto ◽  
...  

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