ACS Applied Energy Materials
·
2024
·
IF 5.4
Fancheng Meng,Peng Chen,Shulin Li,Na Cao,Sheng Cheng,Xiangfeng Wei,Jiangtao Di,Jiehua Liu
Compared with the rapidly developing lithium- and sodium-ion batteries, zinc-air batteries (ZABs) offer the advantages of safety and high energy density. Nevertheless, their applications in underwater conditions are currently limited due to the low oxygen levels in such environments. Drawing inspiration from fish gills, we have successfully constructed a self-breathing zinc-air battery (ZAB) that can extract dissolved oxygen from water and convert it to electrical energy. By utilizing a Co2Fe-NC catalyst and a large-window cathode, the ZAB demonstrates a continuous discharge duration of 68.6 h in the underwater condition, thanks to its well-engineered architecture, optimized catalyst, and gas diffusion layer. Meanwhile, the underwater ZAB outperforms fish gills as it also operates efficiently in air, exhibiting a high capacity of 740 mA h g–1 and a high power density of 320 mW cm–2. Additionally, prolonged cycling tests indicate the ZAB’s capability for stable charging and discharging with minimal potential variation. This study introduces an innovative approach to the development of breathable underwater metal–air batteries.
研究领域:
材料科学
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能源技术
·
仿生学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Minerals Metallurgy and Materials
·
2020
·Vol. 27
·期 9
·1216-1225
·
IF 1.713
Wei Wang,Yue Hong-rui,Xue Xiang-xin
This study investigated the interdiffusion of calcium ferrite/calcium titanate system in the time range of 0–120 min by the diffusion couple method in a CO/N 2 reducing atmosphere at 700°C. The results show that after the diffusion reaction occurred, no longitudinal agglomerations were present on the substrate surface on the calcium titanate side. When the diffusion time was increased to 105 min, a net vacancy flow from calcium titanate to calcium ferrite might have occurred, causing the surface of the calcium ferrite substrate to collapse. The thickness of the diffusion layer of the calcium ferrite/calcium titanate system was about 17–48 µm, which conforms to the parabolic law of diffusion. The diffusion coefficient and the Ti 4+ concentration in the calcium ferrite/calcium titanate system are related. This shows an increase in the diffusion coefficient with the increase of Ti 4+ concentration, and the diffusion coefficient value was in the range of 10 −12 –10 −11 cm 2 ·s −1 .
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY B
·
2023
·
IF 3.3
Jianbang Ge,Biwu Cai,Fei Zhu,Yang Gao,Xinrui Wang,Qianjin Chen,Mingyong Wang,Shuqiang Jiao
Molten salt electrochemistry has been widely used in many fields, especially for metal extraction/refinement. The understanding of mass transfer in molten salts under harsh operation conditions is of great importance to reveal reaction mechanisms and advance fine technologies. It has been generally assumed that natural convection is negligible in stagnant molten salt electrochemistry. Herein, we report an abnormal natural convection in molten LiCl–KCl, with the arising time from 2.37 s at 873 K to 10.13 s at 673 K. Using the concentration correction factor, the derived thickness of the natural convection–diffusion layer (δconv.) was found to be ranging from 128 to 163 μm, much thinner than those in aqueous solutions (∼200 μm). The simulations showed that the notable natural convection resulted from convection–diffusion layer (CDL) convection dominated over the density-driven convection even at high redox concentrations, implying the severe vibration of molten salt systems. To suppress the intense natural convection, we predicted that the use of microelectrodes (with radii less than 23.2 μm for δconv. = 150 μm) would be a promising tool, regardless of their inferior stabilities in high-temperature molten salts at this stage. These innovative findings offer insights into the impact of natural convection on mass transfer in molten salts that have not been previously revealed.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2023
·
IF 4.5
Biwu Cai,Jianbang Ge,Fei Zhu,Yang Gao,Shuqiang Jiao
Natural convection could arise under density gradients of solutions caused by the electrochemical reaction occurring on the electrode surface. This density-driven convection decays rapidly with the decreasing redox concentration, and becomes negligible in dilute solutions (1–2 mM). However, steady-state voltammetry is still observed in these dilute solutions due to the presence of a convection–diffusion layer. Here we studied natural convection effects in low-concentration (5–30 mM) redox solutions and clarified the convection modes in these transient-concentration solutions using cyclic voltammetry and chronoamperometry. The combined theoretical–experimental work demonstrated the coexistence of convection–diffusion layer and density-driven convection. With the use of a 150-μm-radius Pt microelectrode, the convection–diffusion layer convection dominated natural convection in dilute solution (1–5 mM), reinforced mass transport with density-driven convection in low redox concentrations (5–11 mM), and suppressed the density-driven convection at high redox concentrations (>15 mM). The zone diagrams delineating the transition from diffusion to convection were then established to reveal the effects of electrode radius, thickness of the convection–diffusion layer, time scale, and redox concentration on natural convection. Consequently, the use of microelectrodes (∼25 μm radius) could greatly inhibit natural convection effects in 30 mM redox solution.
研究领域:
电化学
·
传质工程
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Hui Huang,Xiaowu Chen,Junmin Zhang,Jinshan Yang,Xiangyu Zhang,Yanmei Kan,Yudong Xue,Hao Qin,Xiao You,Shaoming Dong
As the promising candidates for hot section components used in gas turbines , SiC f /SiC composites suffer severe gas steam/melt corrosion, so their long-term stability depends on the surficial environmental barrier coatings . Here, we provide an alternative method to construct the protective structure by thermal diffusion . Firstly, Y-Al diffusants is diffused into the SiC substrate, forming a Y-Al diffusion layer . Then the diffusion layer can transform to a corrosion-resistant Y(Al)Si x O y layer after oxidative treatment. The compositions and morphologies of the as-received diffusion layer and the Y(Al)Si x O y layer were contrasted. Results show that a Y(Al)Si x O y protective layer, which thickens with the extension of oxidative treatment time and the increase of Y/Al ratio, can be formed on the SiC surface. Concentration gradient caused by preferential oxidation of Y-Al prompts the Y-Al diffusing towards surface. Meanwhile, the oxidation of Y-Al makes the Y(Al)Si x O y layer denser and thicker, and finally form the Y(Al)Si x O y protective layer.
研究领域:
材料科学
·
表面工程学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Green Energy
·
2022
·
IF 3.206
Guofu Ren,Zhiguo Qu,Xueliang Wang,Jianfei Zhang
Self-humidification is becoming a popular strategy for water management in proton exchange membrane fuel cells (PEMFCs), owing to the advantages of decreased volume, cost, and parasitic power of the hydrogen fuel cell engine. Membrane dehydration is one of the key issues that seriously affect the performance and lifespan of PEMFCs under low humidity conditions. In this work, an electrospinning approach was employed to fabricate gas diffusion layers (e-GDLs) composed of nanosized carbon fibers with a nanoscale pore structure. Further, a vapor deposition of Dow Corning Sylgard 184 was utilized to apply a hydrophobic coating to enhance the hydrophobicity of the e-GDL. The fabricated e-GDL can help alleviate the dehydration of the catalyst-coated membrane by increasing the breakthrough pressure. The breakthrough pressure of the e-GDL is five folds higher than that of the current commercial GDL, owing to the combined effects of the nanostructure and enhanced hydrophobicity. This superior characteristic is expected to effectively alleviate membrane dehydration under low humidity conditions. In addition, the e-GDL has excellent elastic deformability, which can effectively alleviate the irreversible damage caused by the pre-tightening force in the stack assembly process, thus enhancing the durability and lifetime of PEMFCs.
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
JOURNAL OF POWER SOURCES
·
2024
·
IF 8.1
Zijie Zhang,Cailin Xiao,Haodong Huang,Mahmood ul Haq,Zheng Li,Lin Zeng
The gas diffusion layer (GDL) enhances the transport efficiency of reaction gases and facilitates the removal of accumulated liquid water, thereby improving water management in anion exchange membrane fuel cells (AEMFCs). Carbon nanotubes (CNTs) are recognized as one of the promising materials to optimize mass transport within GDLs. In this study, we successfully synthesized an abundance of CNTs on the surface of commercial gas diffusion media. The as-prepared CNT layer exhibits exceptionally high hydrophobic properties and forms a hierarchically hydrophobic structure combined with the gas diffusion media, effectively enhancing the mass transfer of the membrane electrode assembly (MEA) and reducing ohmic impedance. Under supersaturation conditions, the power density of the MEA containing CNTs reaches 1031.7 mW/cm 2 , significantly higher than the 760.64 mW/cm 2 observed for the commercial GDL. Further testing demonstrates that the MEA containing CNTs exhibits a limiting current density of 2507.4 mA/cm 2 , which is much superior to the benchmark MEA with the commercial GDL (1591 mA/cm 2 ). Electrochemical impedance spectroscopy analysis reveals that the mass transfer resistance of MEAs with CNTs is lower than that of MEAs with the commercial GDL. More importantly, the phase-field modeling is performed to simulate the transport of the liquid water in the hierarchical GDL.
研究领域:
材料科学
·
能源科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2020
·
IF 4.473
Manojkumar Balakrishnan,Pranay Shrestha,Nan Ge,ChungHyuk Lee,Kieran F. Fahy,Roswitha Zeis,Volker P. Schulz,Benjamin D. Hatton,Aimy Bazylak
We present electrospinning as a versatile technique to design and fabricate tailored polymer electrolyte membrane (PEM) fuel cell gas diffusion layers (GDLs) with a pore-size gradient (increasing from catalyst layer to flow field) to enhance the high current density performance and water management behavior of a PEM fuel cell. The novel graded electrospun GDL exhibits highly robust performance over a range of inlet gas relative humidities (RH). At relatively dry (50% RH) inlet conditions that exacerbate ohmic losses, the graded GDL lowers ohmic resistance and improves high current density performance compared to a uniform GDL with larger pores and fiber diameters. Specifically, the graded GDL facilitates a beneficial degree of liquid water retention at the catalyst layer/GDL interface due to the high capillary pressure inherent in its microstructure, thereby improving membrane hydration. Additionally, enhanced graphitization and connectivity of the graded electrospun fibers improves heat dissipation from the catalyst layer interface compared to the GDL with larger fiber diameters, thereby reducing membrane dehydration. When the inlet RH is raised to fully humid (100% RH) conditions, the graded GDL mitigates liquid water accumulation and lowers mass transport resistance. Specifically, the pore size gradient directs the removal of liquid water from the GDL, resulting in superior performance at high current densities.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 6
·2810
·
IF 4.6
Chang Liu,Shang Li
We developed an integrated gas diffusion layer (GDL) for proton exchange membrane (PEM) fuel cells by growing carbon nanofibers (CNFs) in situ on carbon paper via the electro-polymerization of polyaniline (PANI) on carbon paper followed by a subsequent carbonization treatment process. The CNF/carbon paper showed a microporous structure and a significantly increased pore volume compared to commercial carbon paper. By utilizing this CNF/carbon paper in a PEM fuel cell, it was found that the cell with CNF/carbon paper had superior performance compared to the commercial GDL at both high and low humidity conditions, and its power density was as high as 1.21 W cm−2at 100% relative humidity, which is 26% higher than that of a conventional gas diffusion layer (0.9 W cm−2). The significant performance enhancement was attributed to a higher pore volume and porosity of the CNF/carbon paper, which improved gas diffusion in the GDL. In addition, the superior performance of the cell with CNF/carbon paper at low relative humidity demonstrated that it had better water retention than the commercial GDL. This study provides a novel and facile method for the surface modification of GDLs to improve the performance of PEM fuel cells. The CNF/carbon paper with a microporous structure has suitable hydrophobicity and lower through-plane resistance, which makes it promising as an advanced substrate for GDLs in fuel cell applications.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBON
·
2023
·
IF 10.9
Ting Xu,Hong Huang,Tianrui Lu,Zheng-Jun Wang,Shaojun Zhu,Huile Jin,Jun Li,Xiaochun Zhou,Jing-Jing Lv,Shun Wang
Due to the recent increase in carbon-based gas diffusion layer (GDL) usage for high-rate electrochemical reactors, the study on mitigating anodic corrosion associated with the GDL is imperative. In this study, the anodic corrosion of a high-rate electrochemical flow cell was evaluated using an on-line universal gas chromatography protocol with iridium oxide supported GDL (IrO 2 /GDL) as a model electrode, and it could be evidently alleviated in the alkaline media (1 M KOH) with an inert gas (Ar or N 2 ) environment within current densities of 500 mA cm −2 . In addition, the quantitative CO 2 /CO formation rate and Faradaic efficiencies results, along with the qualitative hydrophobicity maintenance ability of the anode, revealed that the anodic oxidation reaction could be efficiently suppressed in the carbon support samples with both high graphitization and good oxygen evolution reaction (OER) activity, such as the multi-walled carbon nanotubes. Therefore, further modification of the carbon-based GDL itself may help to prevent its corrosion above 500 mA cm −2 . This work is important for tracing the origin of electrocatalysis deactivation and directing the design of carbon materials for the future electrodes that involving the GDL on a high-rate electrochemical reactor.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 11
·4558-4569
·
IF 3.553
Li Tianya,Wang Kejian,Wang Jihao,Liu Yueqi,Han Yufen,Song Jinghui,Hu Hengwei,Lin Guangyi,Liu Yong
Proton exchange membrane fuel cell (PEMFC) is a promising automotive power source that has been gradually applied due to its many advantages such as pollution-free and low-temperature start-up. The gas diffusion layer (GDL) is a key component for water and gas management in PEMFC. It can directly affect the performance of PEMFC. In this paper, we prepared a new type of GDL with hierarchical pores to improve the performance of PEMFC at high current density. The new GDL mainly includes a commercial carbon paper layer and two microporous layers on the same side of carbon paper. The microporous layer near carbon paper was modified with pore former, and another layer was produced without pore former. The pore size of the middle microporous layer was controlled by the content of pore former and times of sonication. From the results of the polarization curve, electrochemical impedance spectroscopy, water contact angle, conductivity, and pore size distribution, it was found that GDL with hierarchical pores shows obvious advancement than commercial GDL. The PEMFC performance was tested to compare the new and commercial GDL. The results show that the peak power of our GDL at 100% humidity reaches 1.24 W/cm 2 and the limit current density is 3.500 A/cm 2 . The modification of the pore size of the microporous layer near the carbon paper side can improve the water management ability of the fuel cell.
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
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Yanchen Lai,Bowen Wang,Bingfeng Zu,Chasen Tongsh,Zhengguo Qin,Qing Du,Shangfeng Jiang,Kui Jiao
Clarifying the mass transfer mechanism of direct ammonia fuel cell (DAFC) can provide theoretical support for solving its complex water and heat management problems. Electrochemical impedance spectroscopy (EIS) as an electrochemical measurement technique that can characterize the losses in various parts of an electrochemical system, but it’s rarely used in DAFC experimental research. Therefore, this study proposes an EIS equivalent circuit model for low-temperature DAFC, which is used to quantitatively characterize the Faradaic impedance, Ohmic impedance, and mass transfer impedance of cells, meanwhile, the model takes into account the influence of solution aggregation in the anode diffusion layer (ADL). This study prepares 3 ADLs with different water contact angles and explores the influence of ADL hydrophobicity on DAFC performance through fitting between equivalent circuit model and experimental results. We find that DAFC with moderately hydrophobicity ADL which water contact angle of 126.5° exhibits better electrochemical performance, with peak power density of 10.07 mW cm −2 . As hydrophobicity decreases, water contact angle reduces to 100.9°, the solution aggregation phenomenon occurring at ADL becomes severe, which in turn increases the Ohmic impedance of 160 mΩ cm 2 and reduces cell performance. The cell with ADL water contact angle of 142.7° doesn’t exhibit solution aggregation in diffusion layer, its Ohmic impedance reduces by 270 mΩ cm 2 compare to the cell with ADL water contact angle of 126.5°, but its performance decrease to 9.23 mW cm −2 due to insufficient reactant supply. This study also explores the influence of ADL hydrophobicity on DAFC output stability. This achievement can enrich the theory of DAFC testing and to some extent fill the gap in the study of DAFC mass transfer mechanism.
研究领域:
能源科学
·
电化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）