The Experts below are selected from a list of 12411 Experts worldwide ranked by ideXlab platform

Byeongdong Kang - One of the best experts on this subject based on the ideXlab platform.

  • Membrane Electrode Assembly for energy harvesting from salinity gradient by reverse electrodialysis
    Journal of Membrane Science, 2018
    Co-Authors: Byeongdong Kang
    Abstract:

    Abstract In this study, the potential of the application of Membrane Electrode Assembly (MEA) to energy harvesting from salinity gradient by reverse electrodialysis is experimentally investigated. The MEA, which consists of a cation exchange Membrane and two porous silver/silver chloride Electrodes, is developed. Power generation from the MEA located between sodium chloride solutions having various differences in concentration is measured. The highest power generation density achieved is 4.1 W m −2 , which is greater than those reported in previous studies on conventional reverse electrodialysis cells.

  • Membrane Electrode Assembly for energy harvesting from salinity gradient by reverse electrodialysis
    Journal of Membrane Science, 2018
    Co-Authors: Byeongdong Kang
    Abstract:

    Abstract In this study, the potential of the application of Membrane Electrode Assembly (MEA) to energy harvesting from salinity gradient by reverse electrodialysis is experimentally investigated. The MEA, which consists of a cation exchange Membrane and two porous silver/silver chloride Electrodes, is developed. Power generation from the MEA located between sodium chloride solutions having various differences in concentration is measured. The highest power generation density achieved is 4.1 W m −2 , which is greater than those reported in previous studies on conventional reverse electrodialysis cells.

Yung-eun Sung - One of the best experts on this subject based on the ideXlab platform.

  • Gas diffusion layer/flow-field unified Membrane-Electrode Assembly in fuel cell using graphene foam
    Electrochimica Acta, 2019
    Co-Authors: Ji-eun Park, Jongkoo Lim, Myung Su Lim, Sungjun Kim, Ok-hee Kim, Dong Woog Lee, Ji Hyun Lee, Yong-hun Cho, Yung-eun Sung
    Abstract:

    Abstract The integration of a gas diffusion layer with a flow-field is essential for enhancing the polymer electrolyte Membrane fuel cell performance. This is achieved by exploiting the ability of a gas diffusion layer-flow-field combination to decrease the size of the reactant pathway and the thickness of the Membrane-Electrode Assembly, thereby reducing electrical and mass transport resistance. This study proposes a unified Membrane-Electrode Assembly that incorporates graphene foam that functions as both a flow-field and a gas diffusion layer. The unified Membrane-Electrode Assembly exhibits higher performance than conventional Membrane-Electrode Assembly on overall current densities region, which is attributed to the increased the pressure drop. Furthermore, its estimated volume power density can be increased because of the 82% decrease in its thickness. Also, the simulation results show that this design enhances the exchange current density due to pressure drop in the graphene foam.

  • Development of high-performance Membrane-Electrode Assembly in unitized regenerative fuel cells
    ELSEVIER SCIENCE INC, 2019
    Co-Authors: Ji-eun Park, Karuppannan M., Kwon O.j., Cho Y.-h., Yung-eun Sung
    Abstract:

    © 2019 The Korean Society of Industrial and Engineering ChemistryIn this work, we investigated the Membrane-Electrode Assembly (MEA) parameters of an oxygen Electrode to develop a high-performance unitized regenerative fuel cell (URFC) that can be operated in fuel cell (FC) and water electrolysis (WE) mode. The MEA parameters including gas diffusion layer, ionomer content, oxygen reduction reaction (ORR) type, oxygen evolution reaction (OER) catalyst, and catalyst loading were optimized by calculating the round-trip efficiency of URFC. The performance in FC mode was largely affected by the MEA parameters compared to that of the WE mode performance. The FC mode performance is crucial for the achievement of high URFC performance. The optimized round-trip efficiency was 49% at 500 mA cm−2, which is comparable or superior to that reported in literature. This result can be attributed to the highly efficient MEA structure suitable for bifunctional catalysts to participate in both ORR and OE

  • Influence of annealing of Membrane Electrode Assembly (MEA) on performance of direct methanol fuel cell (DMFC)
    Journal of Power Sources, 2007
    Co-Authors: Ho-young Jung, Ki-yun Cho, Yong Min Lee, Jung-ki Park, Jong-ho Choi, Yung-eun Sung
    Abstract:

    Abstract The influence of annealing of Membrane Electrode Assembly (MEA) of a direct methanol fuel cell (DMFC) on the cell performance was investigated. The annealing was conducted at various temperatures of 110, 130, 150 and 200 °C. Annealing at 130 °C could produce highest proton conductivity of the recast Nafion binder and electrochemical active surface area of the Electrode, leading to the highest cell performance.

Hexiang Zhong - One of the best experts on this subject based on the ideXlab platform.

Tianshou Zhao - One of the best experts on this subject based on the ideXlab platform.

  • numerical investigations of effect of Membrane Electrode Assembly structure on water crossover in a liquid feed direct methanol fuel cell
    Journal of Power Sources, 2009
    Co-Authors: Weiwei Yang, Tianshou Zhao
    Abstract:

    Abstract A two-phase mass-transport model is employed to investigate the water transport behaviour through the Membrane Electrode Assembly (MEA) of a liquid-feed direct methanol fuel cell (DMFC). Emphasis is placed on examining the effects of each constituent component design of the MEA, including catalyst layers, microporous layers and Membranes, on each of the three water crossover mechanisms: electro-osmotic drag, diffusion, and convection. The results show that lowering the diffusion flux of water or enhancing the convection flux of water (termed as the back-flow flux) through the Membrane are both feasible to suppress water crossover in DMFCs. It is found that the reduction in the diffusion flux of water can be mainly achieved through optimum design of the anode porous layers, as the effect of the cathode porous region on water crossover by diffusion is relatively smaller. On the other hand, the design of the cathode porous layers plays a more important role in increasing the back-flow flux of water from the cathode to anode.

  • numerical investigations of effect of Membrane Electrode Assembly structure on water crossover in a liquid feed direct methanol fuel cell
    Journal of Power Sources, 2009
    Co-Authors: Weiwei Yang, Tianshou Zhao
    Abstract:

    Abstract A two-phase mass-transport model is employed to investigate the water transport behaviour through the Membrane Electrode Assembly (MEA) of a liquid-feed direct methanol fuel cell (DMFC). Emphasis is placed on examining the effects of each constituent component design of the MEA, including catalyst layers, microporous layers and Membranes, on each of the three water crossover mechanisms: electro-osmotic drag, diffusion, and convection. The results show that lowering the diffusion flux of water or enhancing the convection flux of water (termed as the back-flow flux) through the Membrane are both feasible to suppress water crossover in DMFCs. It is found that the reduction in the diffusion flux of water can be mainly achieved through optimum design of the anode porous layers, as the effect of the cathode porous region on water crossover by diffusion is relatively smaller. On the other hand, the design of the cathode porous layers plays a more important role in increasing the back-flow flux of water from the cathode to anode.

  • modeling of water transport through the Membrane Electrode Assembly for direct methanol fuel cells
    Journal of Power Sources, 2008
    Co-Authors: Tianshou Zhao, Weiwei Yang
    Abstract:

    Abstract In this work, a one-dimensional, isothermal two-phase mass transport model is developed to investigate the water transport through the Membrane Electrode Assembly (MEA) for liquid-feed direct methanol fuel cells (DMFCs). The liquid (methanol–water solution) and gas (carbon dioxide gas, methanol vapor and water vapor) two-phase mass transport in the porous anode and cathode is formulated based on classical multiphase flow theory in porous media. In the anode and cathode catalyst layers, the simultaneous three-phase (liquid and vapor in pores as well as dissolved phase in the electrolyte) water transport is considered and the phase exchange of water is modeled with finite-rate interfacial exchanges between different phases. This model enables quantification of the water flux corresponding to each of the three water transport mechanisms through the Membrane for DMFCs, such as diffusion, electro-osmotic drag, and convection. Hence, with this model, the effects of MEA design parameters on water crossover and cell performance under various operating conditions can be numerically investigated.

Weiwei Yang - One of the best experts on this subject based on the ideXlab platform.

  • numerical investigations of effect of Membrane Electrode Assembly structure on water crossover in a liquid feed direct methanol fuel cell
    Journal of Power Sources, 2009
    Co-Authors: Weiwei Yang, Tianshou Zhao
    Abstract:

    Abstract A two-phase mass-transport model is employed to investigate the water transport behaviour through the Membrane Electrode Assembly (MEA) of a liquid-feed direct methanol fuel cell (DMFC). Emphasis is placed on examining the effects of each constituent component design of the MEA, including catalyst layers, microporous layers and Membranes, on each of the three water crossover mechanisms: electro-osmotic drag, diffusion, and convection. The results show that lowering the diffusion flux of water or enhancing the convection flux of water (termed as the back-flow flux) through the Membrane are both feasible to suppress water crossover in DMFCs. It is found that the reduction in the diffusion flux of water can be mainly achieved through optimum design of the anode porous layers, as the effect of the cathode porous region on water crossover by diffusion is relatively smaller. On the other hand, the design of the cathode porous layers plays a more important role in increasing the back-flow flux of water from the cathode to anode.

  • numerical investigations of effect of Membrane Electrode Assembly structure on water crossover in a liquid feed direct methanol fuel cell
    Journal of Power Sources, 2009
    Co-Authors: Weiwei Yang, Tianshou Zhao
    Abstract:

    Abstract A two-phase mass-transport model is employed to investigate the water transport behaviour through the Membrane Electrode Assembly (MEA) of a liquid-feed direct methanol fuel cell (DMFC). Emphasis is placed on examining the effects of each constituent component design of the MEA, including catalyst layers, microporous layers and Membranes, on each of the three water crossover mechanisms: electro-osmotic drag, diffusion, and convection. The results show that lowering the diffusion flux of water or enhancing the convection flux of water (termed as the back-flow flux) through the Membrane are both feasible to suppress water crossover in DMFCs. It is found that the reduction in the diffusion flux of water can be mainly achieved through optimum design of the anode porous layers, as the effect of the cathode porous region on water crossover by diffusion is relatively smaller. On the other hand, the design of the cathode porous layers plays a more important role in increasing the back-flow flux of water from the cathode to anode.

  • modeling of water transport through the Membrane Electrode Assembly for direct methanol fuel cells
    Journal of Power Sources, 2008
    Co-Authors: Tianshou Zhao, Weiwei Yang
    Abstract:

    Abstract In this work, a one-dimensional, isothermal two-phase mass transport model is developed to investigate the water transport through the Membrane Electrode Assembly (MEA) for liquid-feed direct methanol fuel cells (DMFCs). The liquid (methanol–water solution) and gas (carbon dioxide gas, methanol vapor and water vapor) two-phase mass transport in the porous anode and cathode is formulated based on classical multiphase flow theory in porous media. In the anode and cathode catalyst layers, the simultaneous three-phase (liquid and vapor in pores as well as dissolved phase in the electrolyte) water transport is considered and the phase exchange of water is modeled with finite-rate interfacial exchanges between different phases. This model enables quantification of the water flux corresponding to each of the three water transport mechanisms through the Membrane for DMFCs, such as diffusion, electro-osmotic drag, and convection. Hence, with this model, the effects of MEA design parameters on water crossover and cell performance under various operating conditions can be numerically investigated.