Article
Materials Science, Ceramics
Tianya Li, Guang Chen, Guangyi Lin
Summary: In this study, carbon black and acetylene black are used as conductive materials in the microporous layer (MPL) of the gas diffusion layer (GDL). Four different MPLs with various materials and structures are prepared using the spray method. The performance of these MPLs is compared by testing polarization curve, power density, electrochemical impedance spectroscopy, water permeability, pore size distribution, and water contact angle. The results show that the GDL with a double MPL structure exhibits the highest current and power density. At a humidity of 60%, the limiting current density increases by 41% and power density increases by 30% compared to GDL without a gradient pore size. At a humidity of 100%, the limiting current density increases by 41.3% and power density increases by 50% compared to GDL without a gradient pore size.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Shixue Wang, Jing Wang, Yu Zhu
Summary: The thermal conductivity and thermal contact resistance of GDL and MPL greatly impact the performance of PEMFCs. Previous studies have reported conflicting results on the influence of PTFE on GDL conductivity and the magnitude of contact resistance between GDL and MPL. Using the two-thickness method, the thermal conductivity and contact resistance of a Toray GDL with a MPL coating were measured. Results showed that increasing the loading pressure resulted in the increased conductivity of GDL while the MPL coating remained unchanged. Treatment with 20 wt% PTFE reduced the GDL conductivity by 25%. The contact resistance between GDL and MPL was not a major factor in PEMFC design.
JOURNAL OF POWER SOURCES
(2023)
Article
Chemistry, Multidisciplinary
Tong Deng, Henghui Huang, Li Fan, Shaoyi Xu, Hui Li
Summary: This study developed porous transport layers incorporated with microporous layers using a phase inversion/vacuum sintering method. The addition of microporous layers improved the hydrophilicity, decreased the contact resistance, and enhanced the electrochemical performance of the porous transport layers. Additionally, the microporous layers enhanced the material's resistance against corrosion.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Polymer Science
Chongxue Zhao, Haihang Zhang, Zheng Huang, Meng Zhao, Haiming Chen, Guangyi Lin
Summary: In this paper, we report the preparation of a gas diffusion layer (GDL) with different gradient pore size structures. The effects of the two-stage microporous layers (MPL) and the different pore size structures on the performance of proton exchange membrane fuel cells (PEMFC) were investigated. The GDL showed outstanding conductivity and good hydrophobicity. Introducing a pore-making agent altered the pore size distribution of the GDL and increased the capillary pressure difference within the GDL.
Article
Energy & Fuels
Manli Wang, Ming Hou, Yanyan Gao, Haiping Chen, Bo Lv, Wei Song, Zhigang Shao
Summary: A novel substrate-free microporous layer (sfMPL) has been prepared, which extends the usable humidity range of PEMFCs and improves performance. The maximum power density of a single-cell assembled by sfMPL is 36.6% higher than that with conventional methods.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2022)
Article
Chemistry, Physical
Liang Chen, Rui Lin, Mingyu Lou, Kai Lu
Summary: This work proposes a novel strategy to improve the durability of PEMFCs by preparing a wavy microporous layer on the gas diffusion layer (GDL). The wavy-GDL exhibits high structural stability and transfers the corrosion region from the microporous layer to the macroporous substrate, effectively mitigating carbon corrosion. This finding is valuable for promoting carbon corrosion mitigation strategy in other devices.
Article
Nanoscience & Nanotechnology
Kui Li, Shule Yu, Dongguo Li, Lei Ding, Weitian Wang, Zhiqiang Xie, Eun Joo Park, Cy Fujimoto, David A. Cullen, Yu Seung Kim, Feng-Yuan Zhang
Summary: In this study, an engineered liquid/gas diffusion layer (LGDL) with tunable pore morphologies was reported to enable high performance of AEMECs. Compared to a commercial titanium foam, the engineered LGDL significantly improved interfacial contacts, mass transport, and activation of reaction sites in the electrolyzer, leading to outstanding performance. This study provides insight for designing advanced LGDLs for low-cost and high-efficiency AEMECs production.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Biochemistry & Molecular Biology
Adriana Elena Balan, Bogdan Ionut Bita, Sorin Vizireanu, Gheorghe Dinescu, Ioan Stamatin, Alexandra Maria Isabel Trefilov
Summary: We designed a novel cathode microporous layer (MPL) based on highly hydrophobic carbon nanowalls (CNW) and produced high-quality MPLs using plasma-assisted chemical vapor deposition techniques. The MPLs exhibited high porosity, good stability, considerable durability, high hydrophobicity, and substantial conductivity. Single-fuel-cell testing showed improved power performance comparable to industrial quality membrane assemblies.
Article
Thermodynamics
P. Z. Lin, J. Sun, M. H. Shao, M. C. Wu, T. S. Zha
Summary: In this study, the mass transport characteristics of MPLs made of nano-/micro-fibers in PEMFCs were investigated using a model and simulations. The results showed that fiber-based MPLs can significantly reduce the oxygen transport resistance and improve cell performance. Parametric studies suggested that fiber-based MPLs with high porosity, large fiber diameter, and large contact angle can enhance water drainage and gas transport, thereby enhancing PEMFC performance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Chemistry, Physical
Bing Li, Meng Xie, Hao Ji, Tiankuo Chu, Daijun Yang, Pingwen Ming, Cunman Zhang
Summary: In this study, the impact of different carbon blacks on the formation of cathode MPL for proton exchange membrane fuel cells was investigated. It was found that single cells prepared with a mixture of Acetylene black (ACET) and Vulcan XC-72R showed promising power generation performance, while replacing Polytetrafluoroethylene (PTFE) with polyvinylidene fluoride hexafluoropropylene copolymer P(VDF-HFP) as a hydrophobic binder led to a decrease in single cell performance. This study provides valuable insights for material optimization of MPL to enhance fuel cell performance.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Xin Shi, Daokuan Jiao, Zhiming Bao, Kui Jiao, Wenmiao Chen, Zhi Liu
Summary: This study investigates the effects of crack properties in the micro porous layer (MPL) on liquid water saturation, liquid pathway formation, and two-phase mass transport mechanism in proton exchange membrane fuel cells (PEMFC) using a three-dimensional volume of fluid (VOF) model. The results show that the overlap between MPL and gas diffusion layer (GDL) determines the preferred liquid emerging port, while the crack shape has little influence on the liquid water transport.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Jaebong Sim, Minsoo Kang, Kyoungdoug Min, Eunsook Lee, Jy-Young Jyoung
Summary: The water discharge capability of the gas diffusion layer (GDL) in a proton exchange membrane fuel cell (PEMFC) is significantly influenced by the capillary pressure gradient. This study explores three different methods of manufacturing the microporous layer (MPL) to enhance the capillary pressure gradient and improve the water discharge capability of the GDL. Varying the thickness of the MPL, adding hydrophilic carbon black particles, and adjusting the number of MPL loadings with different viscosities are all found to have a notable effect on the performance of the GDL.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Analytical
Qinan Yin, Weitao Gao, Chuang Zhang, Fan Gong, Ziqiang Tu, Yang Li, Guozhang Jiang, Cheng Wang, Zongqiang Mao
Summary: This study improves the water management issue of proton exchange membrane fuel cells (PEMFCs) by enhancing the peak power density of the membrane electrode assembly (MEA) through a cathode hydrophobic microporous layer with added pore forming agent and a buffer microporous layer sprayed over the commercial gas diffusion layer (GDL). The optimized MEA shows a 36.8% increase in peak power density and improved performance under humidity changes, due to efficient water retention capacity and enhanced catalyst layer (CL) wettability.
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
(2023)
Article
Thermodynamics
Yang Yu, Sheng Chen, Heng Wei
Summary: The existence of the microporous layer (MPL) enhances the transport of reactive gas and liquid water in the gas diffusion layer (GDL) of the proton exchange membrane fuel cell (PEMFC). However, the effect of MPL surface cracks on liquid water transport in GDL remains unclear. In this study, a three-dimensional volume of fluid (VOF) model is developed to investigate the relationship between MPL cracks and GDL liquid water transport. The results show that the shape, area, width, and depth of MPL cracks affect the water fraction in GDL, especially in the early stage of water inflow.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Chemistry, Physical
Zhiqiang Xie, Shule Yu, Gaoqiang Yang, Kui Li, Lei Ding, Weitian Wang, Feng-Yuan Zhang
Summary: The study shows that CCMs fabricated with a direct spray deposition method exhibit better performance in PEMECs due to reduced ohmic resistance and improved mass transport. Additionally, simply adjusting the Nafion ionomer content at the anode CL can greatly enhance cell performance, achieving significant performance improvement with reduced cost.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Materials Science, Multidisciplinary
Qian Wang, Runxi Zhu, Peilin Deng, Jing Li, Wei Huang, Qi Chen, Ya-Qiong Su, Chunman Jia, Zhongxin Liu, Zhenye Kang, Yijun Shen, Xinlong Tian
Summary: Direct ethanol fuel cells (DEFCs) are considered as one of the most promising energy resources for portable power devices. However, the current mainstream catalysts used in DEFCs have limitations in the complete oxidation of ethanol. This study proposes ultrathin trimetallic Pt/Ni/Rh nanowires as catalysts, which show high activity, stability, anti-CO poisoning ability, and selective complete ethanol oxidation.
SCIENCE CHINA-MATERIALS
(2023)
Article
Chemistry, Physical
Xiang Lyu, Tim Van Cleve, Erica Young, Jianlin Li, Haoran Yu, David A. Cullen, K. C. Neyerlin, Alexey Serov
Summary: Proton exchange membrane fuel cells (PEMFCs) powered by green hydrogen (H2) are a promising alternative to traditional hydrocarbon-fueled power generators. However, further improvements are needed in efficiency, durability, and low-cost production for widespread adoption. Most strategies to improve PEMFC electrodes utilize single material sets, but anisotropic electrode structures with locally tunable properties may offer enhanced performance due to improved transport.
JOURNAL OF POWER SOURCES
(2023)
Article
Chemistry, Physical
Leiming Hu, Tim Van Cleve, Haoran Yu, Jae Hyung Park, Nancy Kariuki, A. Jeremy Kropf, Rangachary Mukundan, David A. Cullen, Deborah J. Myers, K. C. Neyerlin
Summary: The degradation of polymer electrolyte membrane fuel cells (PEMFCs) catalyst layers for heavy-duty vehicles was studied using a catalyst-specific accelerated stress test (AST). The PtCo/HSC catalyst showed better initial mass activity, larger initial mass transport loss, and faster degradation compared to a-Pt/HSC and Pt/HSC catalysts. Pt dissolution resulted in ECSA losses, either by catalyst particle growth or redeposition in the membrane.
JOURNAL OF POWER SOURCES
(2023)
Article
Electrochemistry
ChulOong Kim, Ivy Wu, Mei-Chen Kuo, Dominic J. Carmosino, Ethan W. Bloom, Soenke Seifert, David A. Cullen, Phuc Ha, Matthew J. Lindell, Ruichun Jiang, Craig S. Gittleman, Michael A. Yandrasits, Andrew M. Herring
Summary: Commercial proton exchange membrane heavy-duty fuel cell vehicles require a more durable composite membrane that can potentially conduct protons. We developed a composite membrane incorporating silicotungstic heteropoly acid (HPA) and other materials, which showed less swelling, more hydrophobic properties, and higher crystallinity than conventional membranes. This composite membrane demonstrated a proton conductivity of 0.130 +/- 0.03 S cm(-1) at 80 degrees C and 95% RH, and survived more than 800 hours under accelerated stress test conditions.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2023)
Article
Electrochemistry
Krysta Waldrop, John J. Slack, Cenk Gumeci, Javier Parrondo, Nilesh Dale, Kimberly Shawn Reeves, David A. Cullen, Karren L. More, Peter N. Pintauro
Summary: MEA with nanofiber mat electrodes containing Pt/C catalyst and Nafion binder were fabricated and evaluated. The electrodes were prepared by electrospinning a solution of catalyst powder, salt-form Nafion, and a carrier polymer. MEAs with anode/cathode catalyst loadings of 0.1 mg(Pt) cm(-2) each and a Nafion 211 membrane demonstrated high power at both high and low RH conditions in H-2/air fuel cell tests. The presence of nm-size pores within the fibers trapped water via capillary condensation, maintaining high proton conductivity of the Nafion binder.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Jeonghoon Lim, Yu Chen, David A. Cullen, Seung Woo Lee, Thomas P. Senftle, Marta C. Hatzell
Summary: By controlling the copper surface coverage, palladium nanocubes as electrocatalysts can effectively reduce nitrate (NO3-) and increase the selectivity for the reduction of nitrite (NO2-) to N2 or NH4+. Partial copper-coated Pd nanocubes can reduce 95% of NO3- and have 89% selectivity for NO2- reduction over 20 cycles (80 h). Complete copper-covered Pd nanocubes can reduce about 99% of NO3- and selectively reduce NO2- to NH4+ with a 70% selectivity over 20 cycles (80 h).
Article
Chemistry, Physical
Deng-Bing Li, Sabin Neupane, Sandip S. Bista, Chuanxiao Xiao, Abasi Abudulimu, Manoj K. Jamarkattel, Adam B. Phillips, Michael J. Heben, Jonathan D. Poplawsky, David A. Cullen, Chun-Sheng Jiang, Randall J. Ellingson, Yanfa Yan
Summary: Our previous work has shown that the formation of a penternary cadmium chalcogenide Cd(O,S,Se,Te) region can reduce front interface recombination in Cd(Se,Te)-based thin-film solar cells. In this work, we demonstrate that managing oxygen during device fabrication is crucial for forming this region. Improper oxygen management leads to low device performance due to the formation of a photoinactive Cd(S,Se) region and reduced absorber quality. Additionally, we investigate carrier transport and collection properties to understand the mechanisms resulting in improved efficiencies approaching 20%.
ACS ENERGY LETTERS
(2023)
Article
Polymer Science
Sunilkumar Khandavalli, Yingying Chen, Nisha Sharma-Nene, Kashyap Sundara Rajan, Samrat Sur, Jonathan P. Rothstein, Kimberley S. S. Reeves, David A. A. Cullen, K. C. Neyerlin, Scott A. A. Mauger, Michael Ulsh
Summary: We investigated the effect of alcohol fraction in a binary water-alcohol solvent mixture on the rheological properties and fiber formation of poly(acrylic acid) in electrospinning. We found that the addition of alcohol induces association/aggregation of the polymer, which affects its viscosity and elasticity. The presence of alcohol also stabilizes the jets/filaments during electrospinning, resulting in improved fiber formation.
JOURNAL OF POLYMER SCIENCE
(2023)
Article
Engineering, Environmental
Xiaohong Gao, Jieli Chen, Yanhui Yu, Fangyuan Wang, Xiao Wu, Xingbo Wang, Weihua Mao, Jing Li, Wei Huang, Qi Chen, Ruisong Li, Chenghang You, Shaolei Wang, Xinlong Tian, Zhenye Kang
Summary: In this work, core-shell structured nanoarrays (NiTe@FeOOH) were designed and constructed for efficient overall seawater splitting. The catalyst exhibited superior performance in both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), with low overpotentials and excellent durability. The strong interactions between NiTe and FeOOH, as well as the surface charge effect, contribute to its high activity and stability.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Suyang Feng, Peng Rao, Xiao Wu, Ke Li, Anyuan Qi, Yanhui Yu, Jing Li, Peilin Deng, Yuliang Yuan, Shaolei Wang, Xinlong Tian, Zhenye Kang
Summary: This study successfully reduced the overpotential of the oxygen evolution reaction (OER) by synthesizing nano-flower-cluster structured CoO@FeSe2/CF catalysts, improving selectivity and stability.
CHINESE JOURNAL OF CHEMISTRY
(2023)
Article
Electrochemistry
Suyang Feng, Peng Rao, Yanhui Yu, Jing Li, Peilin Deng, Zhenye Kang, Shaolei Wang, Zhengpei Miao, Yijun Shen, Xinlong Tian, Zhifu Wu
Summary: Efficient, stable, and inexpensive oxygen evolution reaction (OER) catalysts are explored for the practical application of seawater electrolysis. In this study, CoSe2@CoO/CF catalysts are prepared using a simple and scalable one-step electrodeposition method, and their OER performance is extensively investigated. The CoSe2@CoO/CF catalyst (273 mV) exhibits significantly higher activity than the IrO2 catalyst (435 mV). It can be operated steadily at high current densities (100 mA cm-2) for over 200 hours in 1.0 M KOH + seawater. Moreover, the catalyst shows excellent selectivity with a Faraday efficiency of approximately 98% for OER, while the ClO- concentration is extremely low (1.312 x 10-7 mol L-1) as measured by UV-visible characterization. The impressive performance can be attributed to the urchin-like heterogeneous structure of the catalyst with abundant active centers, as well as the facilitation of para-site electron transfer due to the strong overlap between the Co 2p orbitals of monometallic bi-compound catalysts.
ELECTROCHIMICA ACTA
(2023)
Article
Chemistry, Multidisciplinary
Samuel G. V. Charlton, Amber N. Bible, Eleonora Secchi, Jennifer L. Morrell-Falvey, Scott T. Retterer, Thomas P. Curtis, Jinju Chen, Saikat Jana
Summary: Biofilms are bacterial communities structured within an extracellular matrix, which plays a role in controlling their architecture and mechanical resistance. The research investigates the correlation between biofilm structure and viscoelastic response by comparing biofilms of Pantoea sp. (WT) and a mutant (& UDelta;UDP) with reduced exopolysaccharide production.
Article
Chemistry, Physical
Yanhui Yu, Peng Rao, Suyang Feng, Min Chen, Peilin Deng, Jing Li, Zhengpei Miao, Zhenye Kang, Yijun Shen, Xinlong Tian
Summary: Environmentally friendly energy storage and conversion technologies, like metal-air batteries and fuel cells, are considered promising solutions to address environmental concerns. The oxygen reduction reaction (ORR) is crucial for renewable energy conversion and plays a significant role. However, the complex process of the ORR limits its kinetics. This study proposes a method to fabricate a Co cluster-decorated catalyst, which exhibits improved ORR performance and shows potential as an alternative to Pt catalysts.
ACTA PHYSICO-CHIMICA SINICA
(2023)
Article
Chemistry, Physical
Ruisong Li, Daoxiong Wu, Peng Rao, Peilin Deng, Jing Li, Junming Luo, Wei Huang, Qi Chen, Zhenye Kang, Yijun Shen, Xinlong Tian
Summary: Hydrogen, as a carbon-free energy carrier, is crucial for future clean energy. However, efficient production and combustion of hydrogen still requires precious metal-based catalysts. This study has developed a general movable printing method to synthesize various precious metal-based catalysts with high atomic utilization. These catalysts exhibit higher activities than their nanoparticle counterparts, especially for the superior mass activity of Ru-based catalysts.
Article
Energy & Fuels
Thomas Lickert, Stefanie Fischer, James L. Young, Selina Klose, Irene Franzetti, Daniel Hahn, Zhenye Kang, Meital Shviro, Fabian Scheepers, Marcelo Carmo, Tom Smolinka, Guido Bender, Sebastian Metz
Summary: While the number of publications in the PEM water electrolysis community increases, there is still no common ground in terms of reference hardware and testing protocols. However, the Task 30 Electrolysis within the AFC TCP of IEA has made initial attempts in this area and identified improvements in test hardware and measurement protocols. This paper presents a detailed testing protocol for commercial reference components using a laboratory test cell developed by Fraunhofer ISE, which was evaluated at three different institutions simultaneously. The importance of temperature control and conditioning phase is also demonstrated.
