Journal of the Korean Society for Precision Engineering

A Review on Performance Improvement of Solid Oxide Cells via Atomic Layer Deposition: Min Seong Gwon, Kyoungjae Ju, Jihwan An; J. Korean Soc. Precis. Eng. 2025;42(12):987-995.
Published online December 1, 2025; DOI: https://doi.org/10.7736/JKSPE.025.00017

Abstract
PDF

Atomic Layer Deposition (ALD) has emerged as a promising technique for fabricating thin films that enhance the performance of solid oxide fuel cells and solid oxide electrolysis cells. ALD allows for precise control over film thickness and composition at the atomic level, resulting in uniform and dense thin films. These characteristics enable the deposition of thin, homogeneous layers of various materials onto the porous electrode surfaces of solid oxide cells, thereby increasing electrochemical activity and reducing activation losses. Additionally, thin-film electrolytes produced through ALD can achieve high ionic conductivity and low ohmic losses, facilitating a reduction in the operating temperature of solid oxide cells. This review summarizes recent research trends in applying ALD technology to the fuel electrode, air electrode, and electrolyte of solid oxide cells and discusses design strategies aimed at improving efficiency and long-term stability.

224 View
11 Download

Development of Transformer-based Model for Prediction of PEMFC Remaining Useful Life: Da Hye Geum, Hyeon Do Han, Hyunjun Yang, Heejun Shin, Suk Won Cha, Gu Young Cho; J. Korean Soc. Precis. Eng. 2025;42(12):981-986.
Published online December 1, 2025; DOI: https://doi.org/10.7736/JKSPE.025.00015

Abstract
PDF

A Transformer model to predict the remaining useful life of a fuel cell, which has demonstrated superior performance in analyzing time series data. The dataset was created from long-term performance evaluation experiments conducted in rated power mode, with measurements taken every 10 hours. We preprocessed the raw data using a moving average, allocating 70% for training and 30% for evaluation. The model's performance, evaluated through MAE, MSE, and MAPE, was excellent. The fuel cell's critical voltage, defined as 94.5% of its initial voltage, was measured at 0.719 V. During the experimental run, the actual critical time was 106.6 hours, while the model predicted 106.8 hours, resulting in a 0.19% error. Since the predictions were based on data collected up to 93 hours, the estimated remaining life was 13.8 hours.

276 View
15 Download

Dendrite Growth Suppression in Lithium Metal Batteries with Composite Quasi-solid Electrolytes: Jeongeun Park, Jinhyeong An, Jiwoong Bae; J. Korean Soc. Precis. Eng. 2025;42(12):1037-1043.
Published online December 1, 2025; DOI: https://doi.org/10.7736/JKSPE.025.00010

Abstract
PDF

Secondary batteries are crucial for eco-friendly systems, but existing technologies struggle with energy density and safety issues. This study aims to develop a next-generation battery utilizing quasi-solid electrolytes (QSE), which combine the advantages of both liquid and solid electrolytes. However, QSEs often lack the mechanical strength necessary to prevent lithium dendrite growth. To address this challenge, two strategies were proposed and experimentally validated. The first strategy involves creating a QSE-separator composite (QSE-PI) by integrating QSE with a polyimide (PI) separator. Among the various options, PI with a thickness greater than 20 μm and a pore size of 2-5 μm exhibited superior electrolyte absorption and dendrite suppression. This configuration allowed for rapid lithium plating/stripping, high ionic conductivity (1.7 × 10^-3 S cm^-1), and excellent Coulombic efficiency (99.94%).The second strategy incorporates silica (SiO₂) as a ceramic filler in the QSE-PI to enhance mechanical strength and ion transport. The addition of SiO₂ disrupted polymer crystallinity, increased the amorphous regions, and effectively suppressed dendrite formation. Notably, SiO₂ particles larger than 10 μm improved cycle stability, with the composite maintaining performance for over 50 cycles, compared to only 30 cycles for the version without filler.

128 View
9 Download

Parametric Studies of Ionomer Content in PEMFC MEA with Different Humidity: Byung Gyu Kang, Hyeon Min Lee, Ye Rim Kwon, Sun Ki Kwon, Ki Won Hong, Seoung Jai Bai, Gu Young Cho; J. Korean Soc. Precis. Eng. 2025;42(12):975-980.
Published online December 1, 2025; DOI: https://doi.org/10.7736/JKSPE.025.00006

Abstract
PDF

The ionomer content in the catalyst layer is a crucial design factor that affects the performance of polymer electrolyte membrane fuel cells (PEMFCs). However, the optimal ionomer content can vary based on the surrounding humidity levels. This study systematically evaluated the influence of the ionomer-to-carbon (I/C) ratio (0.00, 0.55, and 0.91) on PEMFC performance under fully humidified (RH 100%) and low-humidity (RH 25%) conditions. Membrane-electrode assemblies (MEAs) were fabricated using a spray coating technique, and their electrochemical properties were analyzed through polarization curves and electrochemical impedance spectroscopy (EIS). Under RH 100%, the MEA with an I/C ratio of 0.55 achieved the highest peak power density of 519.8 mW/cm², indicating a successful balance between proton conductivity and gas transport. Conversely, under RH 25%, the best performance of 203.9 mW/cm² was observed at an I/C ratio of 0.91. This shift is attributed to improved water retention at higher ionomer content, which reduced membrane dehydration and lowered both ohmic and Faradaic resistances. These findings highlight the dual role of the ionomer in facilitating proton transport and managing water balance, emphasizing the necessity of optimizing the I/C ratio according to operating conditions for stable and high-performing PEMFC operation.

545 View
29 Download

Electrochemical Impedance Analyses of ePTFE-reinforced Polymer Electrolyte Membrane-based PEMFC with Varying Thickness and Relative Humidity: Gyutae Park, Subin Jeong, Youngjae Cho, Junseo Youn, Jiwon Baek, Jooyoung Lim, Dongjin Kim, Taehyun Park; J. Korean Soc. Precis. Eng. 2025;42(11):901-907.
Published online November 1, 2025; DOI: https://doi.org/10.7736/JKSPE.025.052

Abstract
PDF

The polymer electrolyte membrane fuel cell (PEMFC) generates electrical energy through electrochemical reactions and is a key technology for sustainable energy. The electrolyte membrane significantly affects performance under varying conditions. This study examines the impact of membrane thickness and relative humidity (RH) on PEMFC performance using j-V curves and electrochemical impedance spectroscopy (EIS). Experiments were conducted with membrane thicknesses of 30, 15, and 5 μm under RH conditions of 100%-100% and 100%-0%. Under RH 100%-100%, performance improved as the membrane thickness decreased, with values of 954, 1050, and 1235 mW/cm² for the 30, 15, and 5 μm membranes, respectively. The 5 μm membrane demonstrated a 23% performance improvement over the 30 μm membrane. Under RH 100%-0%, performances were 422, 642, and 852 mW/cm², with degradation rates of 55.8%, 39.0%, and 32.1%. The 5 μm membrane exhibited the lowest degradation rate, indicating superior performance under low humidity. These results suggest that thinner membranes generally enhance performance and maintain efficiency even in dry conditions.

64 View
3 Download

Pinhole Detection in Thin Film Solid Oxide Electrolytes Using Selective Adsorption of Ag Nanoparticles via a Spark Discharge Generator: Doyoon Kim, Ikwhang Chang, Jong Dae Baek; J. Korean Soc. Precis. Eng. 2025;42(6):441-446.
Published online June 1, 2025; DOI: https://doi.org/10.7736/JKSPE.025.024

Abstract
PDF

Pinhole-free ionic conductors are critical to achieve optimal performance in thin film-solid oxide fuel cells (TF-SOFCs). However, nanoscale defects, especially pinholes, can induce current leakage and contribute to cell failure by creating electrical short circuits. This study introduced a novel methodology for detecting pinholes in yttria-stabilized zirconia (YSZ) thin-film solid oxide electrolytes. The approach utilized selective adsorption of silver (Ag) nanoparticles generated via a spark discharge generator (SDG). Analytical techniques, including focused ion beam (FIB), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), were employed to investigate interactions between Ag nanoparticles and nanoscale defects. Results showed that nanoparticle-based diagnostic methods were efficacious for defect characterization, offering a solution for enhancing the quality of thin-film electrolytes.

17 View
0 Download

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

Abstract
PDF

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

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

29 View
0 Download
Crossref

Micro-hole Array Ceria Functional Layer Embedded Membrane for Durable Polymer Electrolyte Membrane Fuel Cell: Changwook Seol, Segeun Jang, Sang Moon Kim; J. Korean Soc. Precis. Eng. 2024;41(7):533-539.
Published online July 1, 2024; DOI: https://doi.org/10.7736/JKSPE.024.041

Abstract
PDF

For the commercialization of polymer electrolyte membrane fuel cells (PEMFCs), it is essential to achieve high performance while improving the durability of the membrane electrode assembly. In particular, the durability of PEMFCs can be improved by adding radical scavengers, such as CeO2 (ceria), to the membrane. Though it is desirable to insert the ceria at the interface between the membrane and electrode, where the generated radical attack initiates, this increases interfacial resistance and ionic resistance, thereby inducing a probable reduction in initial performance, compared to that of a conventional membrane. Here, we developed modified Nafion electrolyte membranes with a spatially located patterned ceria containing Nafion ionomer to improve durability while minimizing performance degradation. The fabrication process includes an etching process to pattern the electrolyte membrane, and the ceria nanoparticle layer is selectively deposited by spray coating onto the membrane. The synergetic effect of the structural modification of the electrolyte membranes and the introduction of the functional ceria layer exhibited improved chemical durability, while maintaining the initial performance of the PEMFC.

17 View
0 Download

Additional Ionomer-coated Layer for Self-humidifying Polymer Electrolyte Membrane Fuel Cells: Gyutae Park, Dongjin Kim, Junseo Youn, Junghyun Park, Hyoun-Myoung Oh, Taehyun Park; J. Korean Soc. Precis. Eng. 2023;40(12):997-1001.
Published online December 1, 2023; DOI: https://doi.org/10.7736/JKSPE.023.097

Abstract
PDF

In this study, we aim to develop a self-humidifying polymer electrolyte membrane fuel cell (PEMFC) by depositing platinum (Pt) on a membrane using sputtering. After we coated it with a Nafion^® ionomer solution. This is considered a solution that can prevent membrane degradation in low humidity conditions. By introducing this self-humidifying concept, we can expect improved performance compared to conventional PEMFCs. By managing the water content of Nafion^®, we aim to improve both the stability and performance of the PEMFCs. This research contributes to the development of more efficient and reliable PEMFC systems, showing promise for advances in this field.

12 View
0 Download

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

Abstract
PDF

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.

14 View
1 Download

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

Abstract
PDF

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.

12 View
0 Download

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

Abstract
PDF

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

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

17 View
0 Download
Crossref

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

Abstract
PDF

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

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

20 View
0 Download
Crossref

Ultra-Fast Fabrication of YSZ Electrolyte via Flash Light Sintering with ESB Sintering Aid for Solid Oxide Fuel Cells: Yonghyun Lim, Young-Beom Kim; J. Korean Soc. Precis. Eng. 2022;39(2):103-108.
Published online February 1, 2022; DOI: https://doi.org/10.7736/JKSPE.021.120

Abstract
PDF

A high temperature sintering process for solid electrolyte is the main cause of the increase in manufacturing costs of SOFCs. In this study, we developed a novel flash light sintering technique as an alternative sintering process of the conventional thermal sintering process. The YSZ electrolyte films were fabricated by conventional screen-printing method and the flash light sintering process and ESB sintering aid were applied to improve the flash light sinterability of the YSZ electrolyte. In the flash light sintering process, the effect of various pulse conditions such as energy density, and pulse interval were investigated and the microstructure, crystallinity, and sintering behavior of the sintered films were analyzed to demonstrate the effectiveness of the flash light sintering process. The flash light sintered YSZ electrolyte layer was used to fabricate the anode-supported SOFCs and its functionality is successfully demonstrated with the high open circuit voltage. The significance of this study includes minimization of the process time from tens of hours to just a few seconds, thus facilitating the commercialization of SOFCs.

16 View
0 Download

Effects of Current Collecting Methods for Polymer Bipolar Plate of Ultra-Light Polymer Electrolyte Membrane Fuel Cells: Gye Eun Jang, Young Jo Lee, Gu Young Cho; J. Korean Soc. Precis. Eng. 2022;39(2):109-114.
Published online February 1, 2022; DOI: https://doi.org/10.7736/JKSPE.021.118

Abstract
PDF

In this study, polymer bipolar plates for ultra-light polymer electrolyte membrane fuel cells (PEMFCs) were fabricated. Various methods for current collecting were applied to ensure electron conductivity of the polymer bipolar plates. Direct wire contact and Ag sputter process were applied. The Ag current collecting layer fabricated by the sputter process showed a well-covered and defectless surface. After preparations of bipolar plates, the effects of current collecting methods of bipolar plates on the electrochemical properties of PEMFCs were systematically investigated. The maximum power density of PEMFCs with the Ag current collecting of layered polymer bipolar plates decreased 37.39% because of increased ohmic resistance. However, the power/weight of PEMFCs with the Ag current collecting of layered polymer bipolar plates increased 27.23% because of the dramatically reduced weight (-50.63%) of bipolar plates compared to the graphite bipolar plates. We affirm that results in this report can provide meaningful insight for portable electrochemical energy devices.

Citations

Citations to this article as recorded by

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