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"Ho Jun Yoo"

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"Ho Jun Yoo"

Articles
Effects of NaCl Solution on Proton Exchange Membrane Fuel Cell with Serpentine Flow Channel of Different Depths
Dong Kun Song, Ho Jun Yoo, Jung Soo Kim, Ki Won Hong, Do Young Jung, George Ilhwan Park, Gu Young Cho
J. Korean Soc. Precis. Eng. 2025;42(5):399-403.
Published online May 1, 2025
DOI: https://doi.org/10.7736/JKSPE.025.035
Degradation of proton exchange membrane fuel cells (PEMFCs) can be accelerated by impurities in the air. In maritime environments in particular, sodium chloride (NaCl) can reduce the performance of membrane electrode assembly (MEA) in PEMFCs. In this context, we experimentally analyzed effect of flow channel depth on PEMFCs humidified with a NaCl solution at the cathode side. The analysis was conducted in serpentine flow channels with different depths of 0.4, 0.8, and 1.6 mm. The initial performance of unit cells was compared to their performance after applying a constant current for 10 hours. Results showed that the degradation rate correlated positively with the flow-channel depth. Channel depths of 0.4 and 1.6 mm resulted in 2.4% and 7.3% decreases in the maximum power density, respectively. For the 1.6 mm channel depth, the activation loss after 10 hours was larger than the initial loss.
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Evaluation of Electrochemical Performance of PEMFCs with Decontamination Devices at Marine Environments
Ye rim Kwon, Ho Jun Yoo, Byung Gyu Kang, Ki Won Hong, Sun Ki Kwon, Sanghoon Lee, Gu Young Cho
J. Korean Soc. Precis. Eng. 2025;42(1):57-63.
Published online January 1, 2025
DOI: https://doi.org/10.7736/JKSPE.024.109
In this study, we developed and evaluated a simple device for removing ionic impurities that affect the performance of a polymer electrolyte membrane fuel cell (PEMFC) in a marine environment. In such environments, PEMFCs may experience performance degradation due to the presence of Na+ and Cl- in the air. To address this issue, the decontamination device was designed with both heating and cooling components. This device was positioned between a humidifier containing NaCl solution and a humidifier containing deionized water, both connected on the cathode side. The decontamination device effectively removed impurities (Na+ and Cl-) during experiments. As a result, the electrochemical performance of the fuel cell with the decontamination device improved compared to that of the fuel cell without it. Notably, the activation resistance and electrochemical surface area were significantly enhanced, and the ohmic resistance also improved when compared to the fuel cell without the decontamination device.

Citations

Citations to this article as recorded by  Crossref logo
  • Effects of NaCl Solution on Proton Exchange Membrane Fuel Cell with Serpentine Flow Channel of Different Depths
    Dong Kun Song, Ho Jun Yoo, Jung Soo Kim, Ki Won Hong, Do Young Jung, George Ilhwan Park, Gu Young Cho
    Journal of the Korean Society for Precision Engineering.2025; 42(5): 399.     CrossRef
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A Study of Effects of the Repetition of Assembly and the Addition of Activation on Electrochemical Characteristics of PEMFCs
Ji Woong Jeon, Gye Eun Jang, Young Jo Lee, Dong Kun Song, Ho Jun Yoo, Seung Hyeok Hong, Jung Soo Kim, Ye Rim Kwon, Da Hye Geum, Gu Young Cho
J. Korean Soc. Precis. Eng. 2023;40(11):867-872.
Published online November 1, 2023
DOI: https://doi.org/10.7736/JKSPE.023.026
In this study, the effects of repetition of assembly and disassembly of polymer electrolyte membrane fuel cells on electrochemical performance were systematically investigated. Additionally, the effects of additional activation on polymer electrolyte membrane fuel cells were evaluated. All fuel cells were measured every three days. For the disassembled polymer electrolyte membrane fuel cells, membrane electrode assemblies were stored in a vacuum desiccator. For the maintained assembly, fuel cells were stored at room temperature. The performance and electrochemical characteristics of the fuel cell were analyzed by electrochemical impedance spectroscopy. As a result, the addition of activation to maintained assembly fuel cells showed the best performance among fuel cells with other assembly and activation conditions. Repetition of assembly and disassembly, as well as insufficient activation, caused degradation of the performance of fuel cells.
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Evaluate the Activation Effect according to the Voltage Range
Jung Soo Kim, Ho Jun Yoo, Ji Woong Jeon, Dong Kun Song, Ye Rim Kwon, Young Jo Lee, Seung Hyeok Hong, Su Min Lee, Da Hye Geum, Gu Young Cho
J. Korean Soc. Precis. Eng. 2023;40(10):847-852.
Published online October 1, 2023
DOI: https://doi.org/10.7736/JKSPE.023.056
Polymer electrolyte membrane fuel cells (PEMFC) require activation to maximize their performance. Thus, an appropriate activation process is essential for the performance of the fuel cell. In this study, the performance of the fuel cell was investigated by changing the voltage range during the activation process. There were three voltage ranges: 0.3-0.9 V, 0.3-0.6 V, and 0.6-0.9 V. When the fuel cell was activated in the low voltage region, the highest performance was output. On the other hand, it showed the lowest performance at high voltage. The results suggest that it is advantageous to activate the fuel cell with a high current. On the other hand, if activation is performed while outputting at a low current, the generation of water and the electrochemical reaction are insufficient, resulting in a load on the fuel cell. Through this experiment, it was confirmed that the control method greatly affects fuel cell performance when activated.
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A Study on Electrochemical Resistance Change through the Pressurization Process of MEA for PEMFC
Ye Rim Kwon, Dong Kun Song, Ho Jun Yoo, Gye Eun Jang, Young Jo Lee, Jung Soo Kim, Ji Woong Jeon, Da hae Guem, Gu Young Cho
J. Korean Soc. Precis. Eng. 2023;40(7):539-544.
Published online July 1, 2023
DOI: https://doi.org/10.7736/JKSPE.022.150
In this study, the electrochemical characteristics of fuel cell were evaluated after applying a compressive load to the activation area of membrane electrode assembly (MEA) in polymer electrolyte membrane fuel cells. The effects of the pressed area under the compressive load were systematically investigated using polarization curves and electrochemical impedance spectroscopies (EIS) of the fuel cell. Interestingly, the performance of the fuel cell was improved as the pressed area of the MEA was increased from 25.2% to 100% of the active area. In addition, the increased pressed area led to a decrease in the ohmic resistance and the activation resistance of fuel cells.
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Analysis of Electrochemical Behavior of PEMFC Humidified with NaCl Solution Mist Using an Ultrasonic Vibrator
Ho Jun Yoo, Gye Eun Jang, Young Jo Lee, Dong Kun Song, Heeyun Lee, Gu Young Cho
J. Korean Soc. Precis. Eng. 2022;39(12):939-946.
Published online December 1, 2022
DOI: https://doi.org/10.7736/JKSPE.022.096
Durability evaluations were conducted using polymer electrolyte membrane fuel cells in a marine environment. Deionised water and 3.5 wt% of NaCl solution were supplied to the cathode using an ultrasonic vibrator. Performance and electrochemical impedance spectroscopy of fuel cells were measured to evaluate the electrochemical behaviors. Additionally, long-term stability evaluations of PEMFCs were carried out at 0.65 V for 20 h. Following the experiments, scanning electron microscope analysis was conducted to confirm the presence of NaCl on membrane electrode assembly and micro porous layer of fuel cells.

Citations

Citations to this article as recorded by  Crossref logo
  • Effects of NaCl Solution on Proton Exchange Membrane Fuel Cell with Serpentine Flow Channel of Different Depths
    Dong Kun Song, Ho Jun Yoo, Jung Soo Kim, Ki Won Hong, Do Young Jung, George Ilhwan Park, Gu Young Cho
    Journal of the Korean Society for Precision Engineering.2025; 42(5): 399.     CrossRef
  • Evaluation of Electrochemical Performance of PEMFCs with Decontamination Devices at Marine Environments
    Ye rim Kwon, Ho Jun Yoo, Byung Gyu Kang, Ki Won Hong, Sun Ki Kwon, Sanghoon Lee, Gu Young Cho
    Journal of the Korean Society for Precision Engineering.2025; 42(1): 57.     CrossRef
  • A Study of Effects of the Repetition of Assembly and the Addition of Activation on Electrochemical Characteristics of PEMFCs
    Ji Woong Jeon, Gye Eun Jang, Young Jo Lee, Dong Kun Song, Ho Jun Yoo, Seung Hyeok Hong, Jung Soo Kim, Ye Rim Kwon, Da Hye Geum, Gu Young Cho
    Journal of the Korean Society for Precision Engineering.2023; 40(11): 867.     CrossRef
  • A Study on Electrochemical Resistance Change through the Pressurization Process of MEA for PEMFC
    Ye Rim Kwon, Dong Kun Song, Ho Jun Yoo, Gye Eun Jang, Young Jo Lee, Jung Soo Kim, Ji Woong Jeon, Da hae Guem, Gu Young Cho
    Journal of the Korean Society for Precision Engineering.2023; 40(7): 539.     CrossRef
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Effects of NaCl Solution Humidification on Electrochemical Characteristics of PEMFCs
Ho Jun Yoo, Hye Gang Noh, Gye Eun Jang, Young Jo Lee, Dong Kun Song, Gu Young Cho
J. Korean Soc. Precis. Eng. 2022;39(6):451-456.
Published online June 1, 2022
DOI: https://doi.org/10.7736/JKSPE.022.030
In this study, polymer electrolyte membrane fuel cells (PEMFCs) were humidified with NaCl solutions. NaCl solutions were provided to the cathode side of fuel cells by bubbling. De-Ionized water, 3.5 wt% NaCl solution, and 20 wt% NaCl solution were used to evaluate the effects of NaCl. Current density-voltage curves and electrochemical impedance spectroscopies (EIS) of fuel cells were measured. Additionally, the constant-voltage mode long-term stability of PEMFCs humidified with NaCl solution were investigated. Constant-voltage measurements and EIS results imply that the degradation of fuel cells is clearly related with the concentration of NaCl solutions.

Citations

Citations to this article as recorded by  Crossref logo
  • Effects of NaCl Solution on Proton Exchange Membrane Fuel Cell with Serpentine Flow Channel of Different Depths
    Dong Kun Song, Ho Jun Yoo, Jung Soo Kim, Ki Won Hong, Do Young Jung, George Ilhwan Park, Gu Young Cho
    Journal of the Korean Society for Precision Engineering.2025; 42(5): 399.     CrossRef
  • Analysis of Electrochemical Behavior of PEMFC Humidified with NaCl Solution Mist Using an Ultrasonic Vibrator
    Ho Jun Yoo, Gye Eun Jang, Young Jo Lee, Dong Kun Song, Heeyun Lee, Gu Young Cho
    Journal of the Korean Society for Precision Engineering.2022; 39(12): 939.     CrossRef
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  • Crossref