• Journal of the Korean institute of surface engineering
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• v.56 no.6
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• pp.412-419
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• 2023

Anion exchange membrane electrolysis is considered a promising next-generation hydrogen production technology that can produce low-cost, clean hydrogen. However, anion exchange membrane electrolysis technology is in its early stages of development and requires intensive research on electrodes, which are a key component of the catalyst-system interface. In this study, we optimized the pressure conditions of the hot-pressing process to manufacture cobalt oxide electrodes for the development of a high uniformity and high adhesion electrode production process for the oxygen evolution reaction. As the pressure increased, the reduction of pores within the electrode and increased densification of catalytic particles led to the formation of a uniform electrode surface. The cobalt oxide electrode optimized for pressure conditions exhibited improved catalytic activity and durability. The optimized electrode was used as the anode in an AEMWE single cell, exhibiting a current density of 1.53 A cm^-2 at a cell voltage of 1.85 V. In a durability test conducted for 100 h at a constant current density of 500 mA cm^-2, it demonstrated excellent durability with a low degradation rate of 15.9 mV kh^-1, maintaining 99% of its initial performance.

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.961-962
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• 2004

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.951-952
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• 2004

• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.320-321
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• 2005

• 한국초전도학회:학술대회논문집
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• v.11
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• pp.60-60
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• 2001

• Transactions of the Korean hydrogen and new energy society
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• v.17 no.1
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• pp.62-68
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• 2006

High temperature electrolysis is a promising technology to produce massively hydrogen using renewable and nuclear energy. Solid oxide fuel cell materials are candidates as the components of steam electrolysers. However, the polarization characteristics of the typical electrode materials during the electrolysis have not been intensively investigated. In this study, NiO electrode was deposited on YSZ electrolyte by spin coat process and firing at $1300^{\circ}C$. Pt electrode was applied on the other side of the electrolyte to compare the polarization characteristics with those by NiO during electrolysis. The $H_2$ evolution rate was also monitored by measuring the electromotive force of Lambda probe and calculated by thermodynamic consideration. At low current density, Pt showed lower cathodic polarization and thus higher current efficiency than Ni, but the oxidation of Ni into NiO caused the increase of anodic resistance with increasing current density. High overpotential induced high power consumption to produce hydrogen by electrolysis.

• Nuclear Engineering and Technology
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• v.53 no.9
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• pp.3003-3011
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• 2021

A FAC (flow-accelerated corrosion) test was performed for a straight pipe composed of the SA335 Gr P22 and SA106 Gr B (SA106-SA335-SA106) types of steel with welds as a function of the flow rate in the range of 7-12 m/s at 150 ℃ and with DO < 5 ppb at pH levels ranging from 7 to 9.5 up to a cumulative test time of 7200 h using the FAC demonstration test facility. Afterward, the experimental pipe was examined destructively to investigate opposite effects as well as entrance effects. In addition, the FAC rate obtained using a pipe specimen with a 50 mm inner diameter was compared with the rate obtained from a rotating cylindrical electrode. The effects of the complicated fluid flows at the elbow and orifice of the pipeline were also evaluated using another test section designed to examine the independent effects of the orifice and the elbow depending on the distance and the combined effects on orifice and elbow. The tests were performed under the following conditions: 130-150 ℃, DO < 5 ppb, pH 7 and a flow rate of 3 m/s. The FAC rate was determined using the thickness change obtained from commercial room-temperature ultrasonic testing (UT).

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.965-966
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• 2004

• Proceedings of the Korean Ceranic Society Conference
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• 2003.04a
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• pp.21.1-21
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• 2003

• Ceramist
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• v.22 no.2
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• pp.110-121
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• 2019

Triboelectric nanogenerators and piezoelectric nanogenerators are a spotlighted energy harvesting method that converts the wasted mechanical energy from the environment into usable electrical energy. In the case of triboelectric nanogenerators, researches have been mainly focused on high permittivity and flexible polymer materials, and in the case of piezoelectric nanogenerators, researches have been focused on ceramic materials exhibiting high polarization characteristics. Recently, many researches have been conducted to improve durability and power in various environments by using composite materials which have flexible properties of polymer, high permittivity, thermal resistance and high polarization properties of ceramics. This article reviews the energy harvesting studies reported about composites materials using ceramics and polymers.