The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
Min Wang - One of the best experts on this subject based on the ideXlab platform.
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Graphene-doped electrospun nanofiber membrane Electrodes and proton exchange membrane fuel cell performance
Journal of Power Sources, 2016Co-Authors: Meng Wei, Min Jiang, Xiaobo Liu, Min WangAbstract:Abstract A rational Electrode structure can allow proton exchange membrane (PEM) fuel cells own high performance with a low noble metal loading and an optimal transport pathway for reaction species. In this study, we develop a graphene doped polyacrylonitile (PAN)/polyvinylident fluoride (PVDF) (GPP) electrospun nanofiber Electrode with improved electrical conductivity and high porosity, which could enhance the triple reaction boundary and promote gas and water transport throughout the porous Electrode. Thus the increased electrochemical active surface area (ECSA) of Pt catalysts and fuel cell performance can be expected. As results, the ECSA of hot-pressed electrospun Electrodes with 2 wt% graphene oxide (GO) is up to 84.3 m 2 /g, which is greatly larger than that of the Conventional Electrode (59.5 m 2 /g). Significantly, the GPP nanofiber electrospun Electrode with Pt loading of 0.2 mg/cm 2 exhibits higher fuel cell voltage output and stability than the Conventional Electrode.
Meng Wei - One of the best experts on this subject based on the ideXlab platform.
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Graphene-doped electrospun nanofiber membrane Electrodes and proton exchange membrane fuel cell performance
Journal of Power Sources, 2016Co-Authors: Meng Wei, Min Jiang, Xiaobo Liu, Min WangAbstract:Abstract A rational Electrode structure can allow proton exchange membrane (PEM) fuel cells own high performance with a low noble metal loading and an optimal transport pathway for reaction species. In this study, we develop a graphene doped polyacrylonitile (PAN)/polyvinylident fluoride (PVDF) (GPP) electrospun nanofiber Electrode with improved electrical conductivity and high porosity, which could enhance the triple reaction boundary and promote gas and water transport throughout the porous Electrode. Thus the increased electrochemical active surface area (ECSA) of Pt catalysts and fuel cell performance can be expected. As results, the ECSA of hot-pressed electrospun Electrodes with 2 wt% graphene oxide (GO) is up to 84.3 m 2 /g, which is greatly larger than that of the Conventional Electrode (59.5 m 2 /g). Significantly, the GPP nanofiber electrospun Electrode with Pt loading of 0.2 mg/cm 2 exhibits higher fuel cell voltage output and stability than the Conventional Electrode.
Byoungwoo Kang - One of the best experts on this subject based on the ideXlab platform.
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Fully Exploited Oxygen Redox Reaction by the Inter‐Diffused Cations in Co‐Free Li‐Rich Materials for High Performance Li‐Ion Batteries
Advanced Science, 2020Co-Authors: Junghwa Lee, Nicolas Dupre, Mihee Jeong, Shinyoung Kang, Maxim Avdeev, Yue Gong, Won‐sub Yoon, Byoungwoo KangAbstract:To meet the growing demand for global electrical energy storage, high-energy-density Electrode materials are required for Li-ion batteries. To overcome the limit of the theoretical energy density in Conventional Electrode materials based solely on the transition metal redox reaction, the oxygen redox reaction in Electrode materials has become an essential component because it can further increase the energy density by providing additional available electrons. However, the increase in the contribution of the oxygen redox reaction in a material is still limited due to the lack of understanding its controlled parameters. Here, it is first proposed that Li-transition metals (TMs) inter-diffusion between the phases in Li-rich materials can be a key parameter for controlling the oxygen redox reaction in Li-rich materials. The resulting Li-rich materials can achieve fully exploited oxygen redox reaction and thereby can deliver the highest reversible capacity leading to the highest energy density, ≈1100 Wh kg −1 among Co-free Li-rich materials. The strategy of controlling Li/transition metals (TMs) inter-diffusion between the phases in Li-rich materials will provide feasible way for further achieving high-energy-density Electrode materials via enhancing the oxygen redox reaction for high-performance Li-ion batteries.
Amy C. Marschilok - One of the best experts on this subject based on the ideXlab platform.
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Deliberately Designed Atomic-Level Silver-Containing Interface Results in Improved Rate Capability and Utilization of Silver Hollandite for Lithium-Ion Storage
ACS applied materials & interfaces, 2017Co-Authors: Paul F. Smith, Alexander B. Brady, Seung-yong Lee, Andrea M. Bruck, Eric Dooryhee, Yimei Zhu, Kenneth J. Takeuchi, Esther S. Takeuchi, Amy C. MarschilokAbstract:α-MnO2-structured materials are generally classified as semiconductors; thus, we present a strategy to increase electrochemical utilization through the design of a conductive material interface. Surface treatment of silver hollandite (AgxMn8O16) with Ag+ (Ag2O) provides significant benefits to the resultant electrochemistry, including a decreased charge-transfer resistance and a 2-fold increase in deliverable energy density at a high rate. The improved function of this designed interface relative to Conventional Electrode fabrication strategies is highlighted.
Zhigang Shao - One of the best experts on this subject based on the ideXlab platform.
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High-Performance Low-Platinum Electrode for Proton Exchange Membrane Fuel Cells: Pulse Electrodeposition of Pt on Pd/C Nanofiber Mat
ChemElectroChem, 2017Co-Authors: Shaojing Hong, Ming Hou, Yachao Zeng, Zhigang ShaoAbstract:A novel Electrode (E−P Electrode) with a nanofiber structure and Pd/C@dendritic Pt catalysts is prepared by using electrospinning and pulse Electrodeposition (PED) techniques. The maximum power density of the E−P Electrode is 1.43-fold larger than that of the Conventional Electrode at the same cathode Pt loadings of 0.1 mg cm−1. Owing to the in situ deposition of dendritic Pt on the surface of Pd in the Pd/C nanofiber mat, almost all Pt catalysts are accessible for oxygen. The electronic tuning between Pd and Pt enhances the oxygen reduction reaction activity of Pt catalysts. The large Pt surface area of the E−P Electrode mitigates the oxygen-transport resistance in comparison with that of the Conventional Electrode. After the accelerated degradation test for 10000 cyclic voltammetry cycles, the maximum power density of the E−P Electrode only decreases by 12 %. The long-term stability of the E−P Electrode is ascribed to the Pd/C@dendritic Pt catalysts and nanofiber structure.
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A high-performance PEM fuel cell with ultralow platinum Electrode via electrospinning and underpotential deposition
Electrochimica Acta, 2017Co-Authors: Shaojing Hong, Ming Hou, Hongjie Zhang, Yongyi Jiang, Zhigang ShaoAbstract:Abstract A novel PEMFC Electrode (E-U Electrode) with ultralow platinum is prepared by electrospinning and underpotential deposition techniques. The platinum skin (Ptskin) is in situ deposited on the surface of Pd nanoparticle in the electrospun Pd/C catalyst layer. The energy-dispersive X-ray spectroscopy (EDS) mapping of the cross-section of a single fiber confirms that the distribution of Pd/C@Ptskin catalysts and Nafion® ionomer matches well in the E-U Electrode. The high porosity and large electrochemical surface area (ECSA) of the E-U Electrode mitigates the oxygen transfer resistance. The peak power density of the E-U Electrode arrives at 0.62 W cm−2 with a Pt loading of 19 μg cm−2, which is higher than that of the Conventional Electrode (0.55 W cm−2) with a Pt loading of 100 μg cm−2. The degradation rate of peak power density of the E-U Electrode is only 4.8% after accelerated stability test (AST) for 30000 cyclic voltammetry (CV) cycles, demonstrating a better durability than that of the Conventional Electrode. The enhanced durability of the E-U Electrode is attributed to nanofiber structure and interaction between Pd and Pt in the Pd/C@Ptskin catalyst.