Article
Chemistry, Physical
Yinghui Zhang, Youkun Tao, Jing Shao
Summary: Porous metals and carbonaceous materials are gaining attention for applications in polymer electrolyte membrane fuel cells as porous flow fields/distributors, offering high electrical conductivity, porosity, controllable structure, and lightweight. The porous flow distributor has been shown to distribute reactant gases more evenly and improve electrochemical performance compared to conventional ribbed flow distributors, with analyses on the impact of structural/surfacial properties and operating conditions on fuel cell performance. Challenges in performance stability of porous metal flow distributors in corrosive environments and recent advances in corrosion-resistant porous flow distributors are also discussed.
JOURNAL OF POWER SOURCES
(2021)
Article
Green & Sustainable Science & Technology
Le Vu Nam, Eunho Choi, Segeun Jang, Sang Moon Kim
Summary: Spatially locating uniformly patterned PTMPs on the surface of Nafion membrane can effectively improve the performance of proton exchange membrane fuel cells under high temperature and low humidity conditions.
Article
Chemistry, Physical
Umesh Shinde, Poornesh Kumar Koorata, Pranav Padavu
Summary: A three-dimensional single-flow channel computational model was used to study the performance characteristics of polymer electrolyte fuel cells (PEFC). The influence of non-uniform interfacial contact resistance (ICR) and inlet relative humidity (RH), as well as the heterogeneous flow properties of the gas diffusion layer (GDL), on the PEFC performance was evaluated. The results showed that a heterogeneous GDL with nonuniform ICR distribution led to a slight reduction in current density at 0.3V compared to the homogeneous case. However, under specific humidity conditions, an increase in current density was observed. The study also analyzed various parameters such as reactant mass fraction, water concentration, temperature, and cell performance for all simulated cases.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Materials Science, Multidisciplinary
Kazuto Suzuki, Manabu Tanaka, Masahiro Kuramochi, Shun Yamanouchi, Noriko Miyaguchi, Hiroyoshi Kawakami
Summary: Blend polymer nanofibers (BNF) composite membranes, consisting of sulfonated polyimide and polybenzimidazole blends doped with phytic acid, show high proton conductivity, mechanical and chemical stabilities, and low gas permeability. The proton conduction mechanism in the BNF composite membranes involves both vehicle mechanism and proton hopping conduction. Compared to the conventional Nafion NR211 membrane, the BNF composite membrane exhibits superior fuel cell performances at high humidity, low humidity, and high temperature/low humidity.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jujia Zhang, Sian Chen, Haibing Wei, Jin Zhang, Haining Wang, Shanfu Lu, Yan Xiang
Summary: To address the stress loss and plasticization issues in polymer electrolyte membranes during startup/shutdown stages, a proton conductor confinement strategy is introduced. By precisely regulating polymer side-chain structure and defined plasticization quantitative indicator, significant refinements in membrane's conductivity, durability, and single-cell performance are achieved successfully.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Multidisciplinary Sciences
Wanjie Song, Kang Peng, Wei Xu, Xiang Liu, Huaqing Zhang, Xian Liang, Bangjiao Ye, Hongjun Zhang, Zhengjin Yang, Liang Wu, Xiaolin Ge, Tongwen Xu
Summary: The authors have developed a stable polymer membrane that exhibits good performance and durability in electrochemical energy devices such as batteries, electrolyzers, and fuel cells. This anion exchange membrane demonstrates high ion conductivity, excellent barrier properties, and stability exceeding 8000 hours at 80 degrees C in alkali. Furthermore, the authors have successfully achieved roll-to-roll manufacturing of this membrane at a large scale.
NATURE COMMUNICATIONS
(2023)
Article
Thermodynamics
Christian Suarez, Alfredo Iranzo, Baltasar Toharias, Felipe Rosa
Summary: This article presents an experimental analysis of a novel bioinspired design of the channels of a PEMFC, which shows improved water management capability at high humidity and increased peak power.
Article
Chemistry, Physical
Elena Colombo, Andrea Baricci, Daniele Mora, Laure Guetaz, Andrea Casalegno
Summary: Automotive Polymer Electrolyte Membrane Fuel Cells (PEMFC) need to improve durability for better competitiveness. Single cell accelerated stress tests (ASTs) have been standardized to accelerate the development of durable materials. However, current ASTs are not easily correlated with real-world aging. To address this issue, a new hydrogen/air AST was developed to comprehensively mimic the driving functioning. The aging results of state-of-the-art PEMFC were successfully correlated with realistic load cycling, showing a 10-fold acceleration in time.
JOURNAL OF POWER SOURCES
(2023)
Article
Engineering, Chemical
Xingxiao Tao, Kai Sun, Rui Chen, Mengshan Suo, Huaiyu Liu, Zhizhao Che, Tianyou Wang
Summary: This study investigates the gas-liquid two-phase flow in the porous metal foam (PMF) flow field and identifies different flow patterns. Film, plug, and ligament flows are found in the hydrophilic PMF flow field, while slug and droplet flows are found in the hydrophobic PMF flow field. Optimizing pore size, increasing metal foam surface hydrophobicity, and optimizing operating conditions can improve water management in the PMF flow field.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Engineering, Environmental
Yuqing Zhou, Danny J. Lohan, Feng Zhou, Tsuyoshi Nomura, Ercan M. Dede
Summary: In this paper, an inverse design and dehomogenization framework is proposed to discover innovative microreactor flow field designs. Through numerical simulations, trade-offs between reaction performance and fluid flow performance are found for multiple optimized microreactor flow fields. Applying the findings of this study to new reactor flow field designs can enhance performance in biomedical, pharmaceutical, and energy applications.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Thermodynamics
Pranav Padavu, Poornesh K. Koorata, Santoshkumar D. Bhat
Summary: In this study, a numerical model was developed to analyze the effects of depth-dependent reactant flow field geometry on the performance of polymer electrolyte fuel cell (PEFC) under inhomogeneous gas diffusion layer (GDL) compression. It was found that the converging channel design can enhance cell performance, but it is still influenced by GDL compression. The impact of inhomogeneity on cell performance was minimal.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Nanoscience & Nanotechnology
Maniprakundil Neeshma, Santoshkumar D. Bhat
Summary: Polymer electrolyte membranes (PEMs) with fast and selective ionic transport at low relative humidity have high demand for energy conversion devices. In this study, tungsten semi-carbide (W2C@NC) was synthesized and incorporated into a short side chain (SSC)-based membrane matrix to improve water holding and humidification for hydrogen fuel cells. The addition of W2C@NC facilitated membrane hydration and prevented fuel crossover across the membrane, leading to improved fuel cell performance even under low relative humidity conditions.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Jieyang Zhou, Bongjin Seo, Zhe Wang, Yun Wang
Summary: Polymer electrolyte membrane (PEM) fuel cell technology needs to reduce costs to compete with internal combustion engines, and increasing power output can lower cost per kW; issues such as low oxygen concentration and variation in ORR rate under high power may lead to reduced reaction rate and ohmic voltage loss.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Arasy Fahruddin, Djatmiko Ichsani, Fadlilatul Taufany, Budi U. K. Widodo, Wawan A. Widodo
Summary: Research aimed to enhance the performance of polymer electrolyte membrane fuel cells by designing a leaf-inspired cathode side flow field array and adding baffles.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Energy & Fuels
Yajie Song, Xinli Wang, Lei Wang, Fengwen Pan, Wenmiao Chen, Fuqiang Xi
Summary: A twin-nozzle ejector is proposed to improve hydrogen recirculation in the PEMFC system, with simulation results showing advantages and disadvantages of two working modes under different power outputs. This ejector can be used in a wider power output range and enhance system performance.
Article
Energy & Fuels
Bo Zheng, Zhe Wang, Yun Wang
Summary: This study investigates the application of porous media flow fields in polymer electrolyte membrane fuel cells and finds that porous media can effectively enhance thermal removal, electron conduction, and two-phase flow control, while reducing GDL intrusion and deformation and mitigating the risk of GDL/MPL delamination.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2022)
Article
Chemistry, Physical
Jingtian Wu, Huiyuan Liu, Yujiang Song, Yun Wang
Summary: This study investigates the reaction rate and distribution of oxygen and liquid water in polymer electrolyte membrane fuel cells with catalyst layers using three-dimensional modeling. The results show that the catalyst layers have a low effective exchange current density due to a low electrochemical surface area (ECSA) and operate with low oxygen content at low voltages. This leads to significant in-plane variation of the oxygen reduction reaction (ORR) rate, particularly with air cathode reactant flow. The through-plane ORR variations are smaller due to the thin catalyst layer thickness. To improve the performance of the low Pt loading novel catalyst layers, it is necessary to increase the ECSA and the gas diffusion layer (GDL) oxygen diffusivity considerably.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Electrochemistry
Hao Yuan, Bongjin Seo, Yun Wang
Summary: In this study, the spatial variations of discharge precipitate and cathode reaction rate in lithium-air battery were investigated theoretically and experimentally. The results provide insights for designing and optimizing air cathode materials for Li-air batteries.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2022)
Article
Energy & Fuels
Daniela Fernanda Ruiz Diaz, Edgar Valenzuela, Yun Wang
Summary: This paper develops a component-level PEMEC model that incorporates various key factors of a PEMEC electrolysis cell. The model is validated and shown to accurately predict the performance of PEMEC. It can be used for the design and optimization of PEMEC components.
Article
Energy & Fuels
Yiheng Pang, Liang Hao, Yun Wang
Summary: This study presents a machine learning approach using convolutional neural networks to analyze neutron radiography images and quantify liquid water content in polymer electrolyte membrane fuel cells. The results show that using low relative humidity inlet flow can significantly reduce water content, while counter-flow configuration increases water content compared to co-flow configuration.
Article
Thermodynamics
Guobin Zhang, Zhiguo Qu, Yun Wang
Summary: This study conducted a full-scale stack three-dimensional simulation for proton exchange membrane (PEM) fuel cell and investigated the temperature distribution, cell/stack performance, and impact of air cooling. The research found that there are significant temperature differences between the fuel cells on the two sides and in the middle, and that higher temperature sites have lower oxygen content due to increased water vapor concentration. It was also found that increasing the cooling air flow rate decreases stack temperature and reduces temperature variation, thus benefiting the uniform distribution of gases in the stack.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Thermodynamics
Hao Yuan, Yuebang Dai, Hongkun Li, Yun Wang
Summary: This study proposes a three-dimensional nonisothermal model to explore the operation details and spatial variation of electrochemical reaction in high-temperature polymer electrolyte membrane (PEM) fuel cells. Numerical results reveal the spatial distributions of various parameters in PEM fuel cells and provide references for the design and optimization of fuel cell operation conditions.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Review
Chemistry, Multidisciplinary
Guobin Zhang, Zhiguo Qu, Wen-Quan Tao, Xueliang Wang, Lizhen Wu, Siyuan Wu, Xu Xie, Chasen Tongsh, Wenming Huo, Zhiming Bao, Kui Jiao, Yun Wang
Summary: This review provides a comprehensive discussion on the research and development progress of porous flow fields for enhancing fuel cell performance. It covers various aspects such as materials, fabrication methods, fundamentals, and fuel cell performance. The review also highlights future research directions and major challenges in this field.
Review
Chemistry, Multidisciplinary
Linhao Fan, Hao Deng, Yingguang Zhang, Qing Du, Dennis Y. C. Leung, Yun Wang, Kui Jiao
Summary: With the global commercialization of PEMFCs approaching, the challenges of cost, performance, and durability need to be addressed. Developing ultralow Pt loading PEMFCs is crucial for improving their cost competitiveness. This perspective discusses the motivation for ultralow Pt loading and presents important technical development routes. The latest advancements in catalyst layer design under low Pt loading, as well as approaches for accelerating catalyst layer development, are proposed for next-generation PEMFCs.
ENERGY & ENVIRONMENTAL SCIENCE
(2023)
Article
Chemistry, Physical
Ning Wang, Zhiguo Qu, Guobin Zhang, Zetian Tang, Yun Wang
Summary: Ultrahigh power density is crucial for the commercialization of next-generation PEMFCs, particularly in large-size PEMFCs for automobile applications. This study uses a three-dimensional two-phase model to investigate the performance of an automobile fuel cell with various distribution zones. The results show that the dot matrix distribution zone can effectively promote cross flow between adjacent channels, mitigating oxygen starvation and water flooding and improving PEMFC performance at high current density. The counter-flow configuration also leads to higher cell performance and more uniform current density due to internal humidification.
JOURNAL OF POWER SOURCES
(2023)
Article
Materials Science, Multidisciplinary
Cong Feng, Jin Zheng, Yun Wang, Cunman Zhang, Pingwen Ming
Summary: The viscosity characteristics and mechanical behavior of perfluorosulfonic acid (PFSA) ionomers were investigated in this study. A cross-scale model was developed to describe the shear thinning phenomenon, and a modified generalised Maxwell model was proposed to analyze the visco-elastoplastic behavior. The study provides insights into the mechanical response of PFSA ionomers under different strain rates.
APPLIED MATERIALS TODAY
(2023)
Article
Energy & Fuels
Guobin Zhang, Zhiguo Qu, Yun Wang
Summary: This study investigated an innovative proton exchange membrane (PEM) fuel cell design called the integrated porous bipolar plate (BP)-gas diffusion layer (GDL) structure. A three-dimensional (3D) fuel cell model was used to mimic the morphology of the integrated structure and validated using experimental polarization data. The novel design, which used metal foam as both the BP/flow field and GDL, significantly increased cell power density by reducing mass transfer and electron conduction resistances, and by decreasing overall cell thickness through GDL elimination. Smaller pore size (e.g., 60 to 80 PPI) was also found to improve power output and uniform distributions of oxygen and current density.
Article
Chemistry, Physical
Rui Gao, Zhongyu Qiu, Kun Xu, Zihui Zhai, Yuanyuan Cong, Qike Jiang, Guanghui Zhang, Yang Lv, Yizheng Guo, Yongpeng Li, Qingchuan Xu, Yi Xiao, Yiheng Pang, Yun Wang, Yujiang Song
Summary: In this study, F-decorated Fe-N-C was synthesized by pyrolysis of trifluoromethyl imidazole decorated zeolitic imidazolate framework-8 with hemin as Fe precursor. F-Fe-N-C exhibits exceptional activity with high half-wave potential and single cell power density. The enhancement in performance is attributed to the high activity of F-Fe-N-C, abundant pore volume, and scattered distribution of ionomer.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Multidisciplinary Sciences
Linhao Fan, Yun Wang, Kui Jiao
Summary: This study found that adding an ionic liquid can effectively improve the structure of the ultrathin sublayer on the ionomer film, enhancing the O-2 transport efficiency and reducing the O-2 transport loss in the catalyst layer of the proton exchange membrane fuel cell.
FUNDAMENTAL RESEARCH
(2022)
Review
Chemistry, Multidisciplinary
Yun Wang, Yiheng Pang, Hui Xu, Andrew Martinez, Ken S. Chen
Summary: PEM fuel cells and PEM electrolysis cells are closely related electrochemical devices that operate at low temperatures and have the potential for wide applications. However, cost and the lack of hydrogen infrastructure are major challenges for their widespread deployment.
ENERGY & ENVIRONMENTAL SCIENCE
(2022)
