MATERIALS SCIENCE FORUM
·
2023
·
IF 0
Luo Yue,Zhan Feng Deng,Hui Tan,Gui Zhi Xu,Xiao Hu,Jie Song,Gao Qun Zhang,Peng Xiang Song,Xiao Tong Liu
Bipolar plates are a key part of fuel cells. The optimal hot press temperature, pressure, and time were determined in this study. The press condition can directly affect the relative density, thereby improving the conductivity and mechanical property. Several carbon black doped samples were also successfully prepared on the basis of the optimized preparation method. Results show that carbon black optimized the conductivity due to the “conduction bridge”. The maximum conductivity and bending strength reached 345 S/cm and 32.5 MPa, respectively. Key words: fuel cells; bipolar plate; graphite; composite materials.
研究领域:
材料科学
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能源工程
✓ 已验证
DOI
ACS Omega
·
2020
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IF 2.87
Yanwei Zeng,Zihao He,Qianhui Hua,Qunjie Xu,Yulin Min
Bipolar plates, accounting for a large proportion of proton exchange membrane fuel cells (PEMFCs), are highly susceptible to corrosion by H+, SO42–, and so on because of the strong acid-rich and oxygen/hydrogen-rich environments. In this work, the corrosion resistance of aluminum alloy bipolar plates modified in the cathodic environment of PEMFCs has been investigated. A honeycomb structure is constructed by anodizing on an aluminum alloy (AA5052) bipolar plate, and a polyacrylonitrile (PAN) film is prepared by infusing PAN solution on the surface. From scanning electron microscopy and atomic force microscopy, we observe that the porous structure of the aluminum alloy surface is more advantageous for enhancing the mechanical engagement between PAN and the aluminum alloy. Therefore, the PAN film is dense and smooth. Electrochemical tests confirm that the PAN film greatly improves the corrosion resistance of the aluminum alloy bipolar plate under the cathodic environment of the PEMFC. When graphene oxide (GO) is added, the charge-transfer resistance (Rct) is not only improved but also the stability under oxygen-rich acidic conditions is prolonged.
研究领域:
材料科学
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电化学
·
燃料电池工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2022
·Vol. 169
·期 3
·034513
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IF 4.386
Yu Leng,Daijun Yang,Pingwen Ming,Bing Li,Cunman Zhang
Corrosion of stainless steel bipolar plate (BPP) remains a big challenge while it has been considered to be one of the most appropriate candidates for proton exchange membrane fuel cell (PEMFC) in automotive application. This work aims to study comprehensively the effects of temperature, pH, bubbled gas and potential on corrosion behaviours of SS316L. Moreover, SEM and EDX are performed to reveal the evolutions of surface morphology, microstructure and chemical composition of SS316L under different testing conditions. The results indicate that temperature, pH and potential have significant influences on corrosion potential (Ecorr.), corrosion current density (Icorr.) and passive current density (Ip) of SS316L. In addition, interactions between different testing conditions on corrosion resistance are strong. The main corrosion mechanism of SS316L would be shifted from pitting to intergranular or uniform corrosion as pH decreases from 3 ∼ 5 to 0.3 ∼ 1. Accelerated testing solutions with pH in the range of 0.3 ∼ 1 may be suitable to evaluate corrosion resistance of materials for BPP at lower potential. However, simulated testing conditions with pH in the range of 3 ∼ 5 is more appropriate when higher potentials of 1.0 ∼ 1.4 V (vs Ag/AgCl) need to be considered.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2024
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IF 2.6
Li Wenkai,Zeng Haodong,Xie Zhiyong
The bipolar plate is an important part of the proton exchange membrane fuel cell, which has high requirements for mechanical properties and strength. Composite bipolar plates have the advantages of easy processing and corrosion resistance, but there are problems such as difficulty in balancing between mechanical properties and electrical conductivity. In this study, surface-coating modification of chopped carbon fibers was carried out by catalytic chemical vapor deposition, and multi-walled carbon nanotube-coated carbon fiber composites with better interfacial contact properties and improved specific surface area were prepared and added to polyvinylidene fluoride/expanded graphite to synthesize composite bipolar plates. Due to the selective distribution of carbon nanotubes and the synergistic construction of conductive pathways with carbon fibers, the performance of the composite bipolar plate was improved, with a conductivity of 116.01 S/cm, a flexural strength of 50.37 MPa, and both good hydrophobicity and corrosion resistance and a corrosion current density of 0.804 µA cm −2 . The results show that the prepared composite bipolar plates meet the requirements in fuel cell use, and the use of carbon nanotubes coated with carbon fibers to synergistically construct conductive networks has also proven to be a potential performance enhancer for composite bipolar plates.
研究领域:
材料科学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2025
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IF 14.2
Yanhe Zhuang,Ruihua Rao,Zixin Wu,Jiaming Zhang,Pengpeng Dai,Shuyu Zhou,Xin Song,Chenglong Yu,Yuxin Liu,Shixi Zhao
The performance of bipolar plates in PEMFC directly affects their efficiency and commercial application. In this study, to address the issue of long preparation times and low production efficiency associated with traditional graphite bipolar plates, we optimize the epoxy resin curing system to significantly enhance the preparation efficiency and overall performance of composite graphite bipolar plates (CBPs). 1- o -Tolylbiguanide (OTB) is used as the curing agent, and 2-methylimidazole (2-MZ) is introduced as an accelerator, allowing the epoxy resin to fully cure in 3min–5min at 160 °C, greatly reducing the preparation time. Kinetic analysis shows that 2-MZ reduces the apparent activation energy of the curing reaction, accelerates the ring-opening of epoxy groups and the formation of the crosslinking network, and optimizes the resin molecular chain structure. As a result, the flexural strength and conductivity of the CBPs are significantly improved. Additionally, the introduction of anhydrous ethanol enhances the interfacial bonding between the resin and graphite filler, improving the conductive uniformity of CBPs. Electrochemical tests demonstrate that the optimized CBPs exhibit excellent corrosion resistance under simulated PEMFC acidic conditions, meeting the standards set by the DOE. This study provides a feasible strategy for the efficient, low-cost preparation of high-performance composite graphite bipolar plates, advancing the commercialization of PEMFCs.
研究领域:
材料科学
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燃料电池工程
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产品关联
DOI
高影响因子
eTransportation
·
2021
·
IF 0
Yu Leng,Daijun Yang,Pingwen Ming,Cunman Zhang
Reliable assessment of corrosion resistance is critical in seeking the appropriate materials for bipolar plate (BPP) while corrosion of BPP still remains a key challenge in proton exchange membrane fuel cell (PEMFC). In this work, the effects of accelerated and simulated testing conditions as well as potential on corrosion behaviours and microstructure evolutions of stainless steel bipolar plate are studied with SS316L by potentiodynamic and potentiostatic tests, and electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). Moreover, the rationalities of evaluating corrosion resistance of materials for BPP under accelerated and simulated testing conditions with different potentials are analyzed based on electrochemical tests and corrosion mechanisms of SS316L. The results reveal that pitting is the main corrosion mechanism for SS316L in the simulated or real PEMFC working conditions. However, the dominant corrosion mechanisms are changed to intergranular and uniform corrosion at the potentials of 1.15 V–1.55 V (vs. SHE), respectively, when tests are performed in accelerated conditions with pH = 0.3. The results indicate that the accelerated conditions may be inappropriate for evaluating corrosion resistance of materials for BPP, especially at higher potentials.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Chun Ouyan,Xinlong Zhang,Mingfang Wu,Damao Xun,Pingping Gao
Ni-P coatings including TiN nanoparticles are prepared by electroless plating on Ti plate, which is used as bipolar plates of proton exchange membrane fuel cells (PEMFCs). Scanning electronic microscope (SEM) and X-ray diffraction (XRD) are used to characterize the surface morphology and phases of the coatings, respectively. Corrosion resistance of Ni-P and Ni-P/TiN coatings are measured in the simulated solution of PEMFCs. The interfacial contact resistances (ICR) between carbon paper and bipolar plates are conducted by applied different forces. Potentiostatic polarization tests are prepared at different voltage by bubbling air and H2 at 70 °C, respectively. It is indicated that TiN particles as a core enclosed by Ni-P are entrapped into the coating by SEM images. Comparing to Ni-P coatings, the Ni-P/TiN coating shows better behaviors of corrosion resistance and low ICR. The good corrosion resistance is attributed to the formation of coating and the compact surface morphology. Hence, Ti metal with electroless plating Ni-P/TiN coating is a potential candidate for applying in the bipolar plates of PEMFCs
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2023
·Vol. 13
·期 14
·2055
·
IF 5.3
Wenkai Li,Yixin Zhao,Xingchen Pan,Mingqi Liu,Shi Qiu,Zhiyong Xie
Composite bipolar plates (BPs) hinder their application in proton exchange membrane fuel cells (PEMFC) because of their poor conductivity and mechanical properties. Nanofillers can effectively solve this problem but often have a limited effect due to their easy agglomeration. In this work, a continuous mesh carboxylated multi-walled carbon nanotube (MWCNT) coating on the surface of graphite was synthesized by chemical vapor deposition (CVD) and carboxylation modification, and the composite BPs were prepared by molding using prepared reticulated carboxylated MWCNTs, expanded graphite, and resin. By optimizing the carboxylation treatment time and the content of the nano-filler, the composite BPs had the best performance at a 15 min carboxylation treatment time and 2.4% filler content. The planar conductivity reached up to 243.52 S/cm, while the flexural strength increased to 61.9 MPa. The thermal conductivity and hydrophobicity were improved compared with the conventional graphite/resin composite BPs, and good corrosion resistance has been demonstrated under the PEMFC operating environment. This work provides a novel nanofiller modification paradigm for PBs.Keywords:carbon nanotubes;carbon nanotube functionalization;graphite/resin composites;bipolar plate;chemical vapor deposition
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RENEWABLE ENERGY
·
2025
·
IF 9.1
Wei Liu,Wenruo Li,Jie Wang,Xinzhao Zhao,Tianyi Wang,Haoyu Zhan,Xiannian Sun,Naibao Huang
Proton exchange membrane fuel cells (PEMFC/PEMWE) are important devices for the conversion and utilization of renewable hydrogen energy. By electrodeposition in deep eutectic solvent (DES) mixed with critic acid (CA), a Nb-doped amorphous carbon coating (ACC) with enhanced conductivity was successfully grown on the surface of 316L stainless steel bipolar plates. The addition of Nb significantly lowered contact resistance of ACC to 13.8 mΩ cm 2 , while the Nb-doped ACC still exhibits excellent corrosion resistance and high electrochemical stability up to 300 h. Theoretical calculation and characterization indicate that the solvent shell structure formed between CA and Nb 5+ ions in the electrolyte facilitates the migration of Nb 5+ to the cathode, thereby promoting more Nb deposition. With the help of CA, the nucleation process of the coating shifts to instantaneous nucleation, favoring the formation of a dense and smooth coating. Moreover, the chemical adsorption of CA on the stainless steel surface enhances the adhesion between the ACC and the substrate. The excellent electrochemical property, strong interfacial adhesion, and high stability in service of the Nb-doped ACC indicates that the proposed electrodeposition method is a promising approach for fabricating ACC-modified stainless steel serving as bipolar plates.
✓ 已验证
产品关联
DOI
高影响因子
SURFACE REVIEW AND LETTERS
·
2018
·
IF 0.734
GAO PINGPING,OUYANG CHUN,XIE ZHIYONG,TAO TAO
The Ni-P/TiN coating was used as bipolar plate by electroless plating on Ti. Surface morphology and phase structure of the coatings were characterized by SEM and XRD, respectively. Corrosion resistance of Ni-P and Ni-P/TiN coating was measured in the simulated solution of Proton exchange membrane fuel cells (PEMFCs). The interfacial contact resistance (ICR) was conducted by applied different forces. SEM images indicated that the particles of core–shell structure were formed on the surface of coating on Ti substrate. The core–shell structure was composed of TiN core and Ni-P electroless plating shell. Compared with Ni-P coatings, the Ni-P/TiN coating showed better corrosion resistance behaviors and low ICR (below 10 m Ω cm − 2 under pressure of 200 N/cm 2 ) . TiN particles and distribution of core–shell were in favor of the formation of coating and compact surface morphology. The good conductivity was attributed to the compact surface morphology of coating. The Ni-P/TiN coating showed excellent interfacial conductivity and good corrosion resistance at applied high potential in simulated solution of PEMFCs.
研究领域:
材料科学
·
能源工程
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Xiuping Zhang,Henghui Huang,Jiantao Fan,Yudi Niu,Li Fan,Shaoyi Xu,Hui Li
Carbon/polymer binder composite bipolar plates for proton exchange membrane fuel cells have attracted attention for their corrosion resistivity and ease of manufacturing. However, the hot-pressing fabrication process often leads to a resin-rich surface on the plate, which may increase the interfacial contact resistance. A number of studies have been reported to reduce resin accumulation on the surface. However, most reported methods have focused on how to exceed the United States Department of Energy conductivity and mechanical targets. Their fabrication methods are often complicated, which is hard to form flow channels directly in manufacturing. Herein, we propose a simple layer-by-layer method to prepare graphite/resin composite bipolar plates. During compression of the multilayer graphite/resin powder, elevated temperature and pressure make the resin in the inner polymer-rich layer flow toward the outer resin-deficient layers. Scanning electron microscopy with energy-dispersive X-ray analysis shows an unbroken “smiling” curve of carbon content along the whole cross-section, suggesting a continuous distribution of the resin across the whole composite. The resulting composite demonstrates a better interfacial contact resistance (9.2 mΩ cm2@100 psi) and a flexural strength (44.3 MPa) than the plates prepared by a single-layer method. Flow channels with a good molding accuracy (±4 μm) are also observed. Single-cell testing with the gradient-structured composite plate shows excellent cell performance: the cell voltage is 0.67 V at 1 A cm–2, and the maximum power density reaches 0.99 W cm–2. In situ electrochemical impedance analysis demonstrates that compared to an analogue using the single-layer loading method, the cell with gradient structured plates displays lower ohmic and mass transfer resistance than the cell using the plates prepared by a single-layer method.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Wei Liu,Wenjing Dong,Likui Guo,Yuan Feng,Naibao Huang,Xiannian Sun
In this paper, a convenient electrodeposition method is proposed to directly fabricate a reduced graphene oxide-amorphous carbon composite coating (rGO-ACC) on a 316L stainless steel substrate. The rGO-ACC coating is achieved through a one-step reduction by utilizing a choline chloride-ethylene glycol deep eutectic solvent (DES) with the dispersion of graphene oxide. The analysis results from SEM, Raman and XPS reveal that the obtained rGO-ACC coating, with layered wrinkle morphology, uniformly covers and covalently bonds to 316L stainless steel substrate. Potentiodynamic and potentiostatic polarization tests showed that the corrosion current densities of rGO-ACC coated 316L stainless steel were of the order of 10 -7 A cm −2 in simulated proton exchange membrane fuel cells (PEMFC) working environment, indicating a significant improvement of corrosion resistance of 316L and an excellent electrochemical stability. Meanwhile, compared with the naked 316L steel, the interfacial contact resistance (ICR) of the coated stainless steel is significantly reduced due to the outstanding electrical conductivity of the coated rGO. The results manifested that deposited rGO-ACC on steel surface may be a highly promising modification method for PEMFC metal bipolar plates.
研究领域:
材料科学
·
电化学
·
能源材料
·
表面工程
·
燃料电池技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）