• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.19 no.1
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• pp.57-62
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• 1983

The galvanic anodes have three kinds of Zn alloy anode, Al alloy anode and Mg alloy anode, which are widely used in cathodic protection for all metal structures in water or under ground. This paper to be used for designing of the grounding cell has reached the following conclusion as the results of an experimental study on the characteristics of such galvanic anodes for corrosion protection of pipings: 1) Zn alloy anode was the best when the specific resistance of the environment was bellow 1000 $\Omega$.cm, and when above 1000 $\Omega$.cm, Mg alloy anode to be used for designing of the grounding cell was the best. 2) Al alloy anode was better than Mg alloy anode for grounding cell when the specific resistance was bellow 500 $\Omega$.cm, but the Al alloy anode in all the environments reduced the characteristics of galvanic anode to the lower grade than those of Zn alloy anode. 3) Each impressed voltage (E) of the anodes at which drainage current density ($\rho$) begins rapidly increasing is quantitatively presented as follows: \circled1 E sub(Zn)=log (4.9465/$\rho$super(0.0639))+11$\times$10 super(-6)$\rho$super(0.8923i) \circled2 E sub(Al)=log (4.9306/$\rho$super(0.0525))+13$\times$10 super(-6)$\rho$super(0.9314i) \circled3 E sub(Mg)= log (3.7086/$\rho$super(0.0988))+181$\times$10 super(-6)$\rho$super(0.5406i) 4) The empirical equations between the drainage current density (i) and impressed environment are modeled as the following type. logi=g+root(n.E+r)(g,n,r; constants)

• Journal of Korean Society of Water and Wastewater
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• v.26 no.6
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• pp.883-888
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• 2012

Anode electrode is one of the most important factors in microbial fuel cell (MFC). This study was conducted to investigate the effects of mediator as methylene blue (MB) and electrode surface area on the power density of MFC with sponge and carbon nano tube (CNT) electrode (SC). The SC electrode with MB (MC) showed the maximum power density increased from 74.0 $mW/m^2$ to 143.1 $mW/m^2$. The grid shaped sponge and CNT (GSC) electrode showed the maximum power density of 209.2 $mW/m^2$ due to the increase of surface area from 88.0 to 152.0 $cm^2$. The GSC electrode with MB (GMC) revealed the maximum power density of 384.9 $mW/m^2$ which was 5.2 times higher than that obtained from the MFC with SC. Therefore MB and increase of surface area led to enhance the performance of microbial fuel cell such as power density.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.6
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• pp.636-641
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• 2016

Alkaline water electrolysis is commercial hydrogen production technology. It is possible to operate MW scale plant. Because It used non-precious metal for electrode. But It has relatively low current density and low efficiency. In this study, research objective is development of anode for alkaline water electrolysis with low cost, high corrosion resistance and high efficiency. Stainless steel 316L (SUS 316L) was selected for a substrate of electrode. To improve corrosion resistance of substrate, Nickel (Ni) layer was electrodeposited on SUS 316L. Ni-Fe alloy was electrodeposited on the passivated Ni layer as active catalyst for oxygen evolution reaction(OER). We optimized preparation condition of Ni-Fe alloy electrodeposition by changing current density, electrodeposition time and composition ratio of Ni-Fe electrodeposition bath. This electrodes were electrochemically evaluated by using Linear sweep voltammetry (LSV) and Cyclic voltammetry (CV). The Ni-Fe alloy (Ni : Fe = 1 : 1) showed best activity of OER. The optimized electrode decreased overpotential about 40% at $100mA/cm^2$ compared with Ni anode.

• Journal of Electrochemical Science and Technology
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• v.15 no.3
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• pp.388-404
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• 2024

In the present work, the operating parameters were optimized using Box Behnken Design (BBD) in response surface methodology (RSM) to maximize the hydrogen production rate (R₁) and hydrogen production rate per unit watt consumed (R₂) of a proton exchange membrane electrolysis cell (PEMEC), a third response (R₃) which was the sum of the scaled values of R₁ and R₂ were selected to be maximized so that both hydrogen production rate and hydrogen production rate per unit watt consumed could be maximized. The major parameters which were influencing the experiment for enhancing the output responses were oxygen electrode/anode electrocatalyst loading (A), current supplied (B) and water inlet temperature (C). The commercial proton exchange membrane Nafion^® was used as the electrolyte. The acetylene black carbon (C_AB) supported IrO₂ was used as the electrocatalyst for preparing oxygen electrode/anode whereas commercial Pt (40 wt%)/C_HSA was used as the H₂ electrode/cathode electrocatalyst. The quadratic model was developed to predict the output/ responses and their proximity to the experimental output values. The developed model was found to be significant as the P values for both the responses were < 0.0001 and F values were greater than 1. The optimum condition for both the responses were O₂ electrode/anode electrocatalyst loading of 1.78 mg/cm², supplied current of 0.33 A and water inlet temperature of 54℃. The predicted values for hydrogen production rate (R₁) and hydrogen production rate per unit watt consumed (R₂) were 2.921 mL/min and 2.562 mL/(min·W), respectively obtained from the quadratic model. The error % between the predicted response values and experimental values were 1.47% and 3.08% for R₁ and R₂, respectively. This model predicted the optimum conditions reasonably in good agreement with the experimental conditions for the enhancement of the output responses of the developed PEM based electrolyser.

• Corrosion Science and Technology
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• v.6 no.2
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• pp.44-49
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• 2007

Dimensionally stable anodes have been widely used to cathodically protect the metallic materials in corrosive environments including concrete structure as the insoluble anode. Lifespan of the anode for concrete construction can be determined by NACE TM0294-94 method. Lifespan of conductive oxide electrode would be affected by thermal treatment condition in the process of sol-gel coatings. This work aims to evaluate the effect of thermal treatment temperature on the lifespan of the $RuO_{2}$ electrode. $450^{\circ}C$ treated conductive oxide electrode showed the excellent properties and its lifespan was evaluated to be over 88 years in 3% NaCl, 4% NaOH, and simulated pore water. This behavior was related to the formation of $RuO_{2}$.

• Applied Chemistry for Engineering
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• v.28 no.1
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• pp.118-124
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• 2017

An air cooling, open cathode type polymer electrolyte membrane fuel cell (PEMFC) has the advantages of system simplification and cost effectiveness. Open cathode PEMFC could suffer from reduced performance due to the membrane dehydration in low humidity of air. Effects of the cathode air flow rate, anode purge interval and long term storage on PEMFC performance were investigated in this work. Fan voltage is an important factor on air cooling PEMFC performance because the cathode air flow rate and stack temperature were controlled by fan voltage. The dead ended anode (DEA) method was applied to increase hydrogen usage. Periodical purge was used to discharge accumulated water and gas. The influence of long term non-operating condition on PEMFC performance degradation due to the membrane dehydration was also studied and the quick recovery method was developed.

• Composites Research
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• v.35 no.6
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• pp.365-370
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• 2022

According to the rapid growth of electric vehicle (EVs) and E-mobility market, Li-ion batteries are one of the most progressive technologies. The demand of LIBs with high energy capacity, rate performance and fast charging is continuously increasing, hence high-performance LIBs should be developed. Si is considered as the most promising anode material to improve energy density because of its high theoretical capacity. However, Si suffers large volume chances during the charging and discharge process, leading to the fast degradation of cycle performance. Therefore, polymeric binders play a key role in electrochemical performance of Si anode by efficiently enduring the Si expansion and maintaining the binding networks in electrode. In this review, we explain the role of polymeric binders in electrode and introduce the anode binders with enhanced mechanical and chemical properties which can improve electrochemical performances of Si-based anode.

• Journal of Environmental Science International
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• v.27 no.6
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• pp.467-475
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• 2018

The lifetime of the electrode is one of the most important factors on the stability of the electrode. Since the lifetime of the DSA (Dimensionally stable anode) electrode is long, an accelerated lifetime test is required to reduce the test time. Beacuse there is no basis or standard method for accelerated lifetime testing, many researchers use different methods. Therefore, there is a need for basis and methods for accelerated lifetime testing that other researchers can follow. We designed a reactor system for accelerated lifetime testing and planned specific methods. Reactor system was circulating batch reactor. Reactor volume and cooling water tank were 12.5 L and 100 L, respectively. Electrode size was $2cm{\times}3cm$ (real electrolysis area, $5cm^2$). In order to maintain the harsh conditions, accelerated lifetime test was carried out in a high current density ($0.6A/cm^2$) and low electrolyte concentration (NaCl, 0.068 mol/L). Maintaining a constant temperature was an important operation parameter for exact accelerated lifetime test. As the accelerated lifetime test progressed, the active component of electrode surface was consumed and desorption occurred. At the point of 5 V rise, corrosion of the surface of the base material(titanium) also started.

• Corrosion Science and Technology
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• v.6 no.6
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• pp.269-274
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• 2007

The corrosion of steel in concrete is significant in marine environment. Salt damage is one of the most detrimental causes to concrete bridges and port structures. Especially, the splash and tidal zones around water line are comparatively important in terms of safety and life-time point of view. During the last several decades, cathodic protection (cp) has been commonly accepted as an effective technique for corrosion control in concrete structures. Zn-mesh sacrificial anode has been recently developed and started to apply to the bridge column cp in marine condition. The detailed parameters regarding Zn-mesh cp technique, however, have not well understood so far. This study is to investigate how much Zn-mesh cp influences along the concrete column at elevated temperature. About 100 cm column specimens with eight of 10 cm segment rebars have been used to measure the variation of cp potential with the distance from Zn-mesh anode at both $10^{\circ}C$ and $40^{\circ}C$ in natural seawater. The cp potential change and current diminishment along the column specimens have been discussed for the optimum design of cp by Zn-mesh sacrificial anode.

• Journal of the Korean Ceramic Society
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• v.54 no.5
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• pp.438-442
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• 2017

This paper reports the facile synthesis of microlamella-structured porous copper (Cu)-oxide-based electrode and its potential application as an advanced anode material for lithium-ion batteries (LIBs). Nanowire-like Cu oxide, which is created by a simple thermal oxidation process, is radially and uniformly formed on the entire surface of Cu foam that has been fabricated using a combination of water-based slurry freezing and sintering (freeze casting). Compared to the Cu foil with a Cu oxide layer grown under the same processing conditions, the Cu foam anode with 63% porosity exhibits over twice as much capacity as the Cu foil (264.2 vs. 131.1 mAh/g at 0.2 C), confirming its potential for use as an anode electrode for LIBs.