Journal: Journal of the Electrochemical Society

Abbreviation

J. Electrochem. Soc.

Publisher

The Electrochemical Society

Journal Volumes

ISSN

0013-4651
1945-7111

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Publications 1 - 10 of 140
  • Operando Properties of Gas Diffusion Layers: Saturation and Liquid Permeability
    Item type: Journal Article
    Eller, Jens; Roth, Jörg; Marone, Federica; et al. (2017)
    Journal of the Electrochemical Society
    Polymer electrolyte fuel cells (PEFC) require a sophisticated water management to operate efficiently, especially at high current densities which are needed to reach system cost targets. The description of the complicated two-phase water transport remains a challenge in PEFC models and requires experimental validation on various length scales. In this work, operando X-ray tomographic microscopy (XTM) with scan times of 10 s was used to depict the liquid water at defined conditions at a technically relevant cell temperature of 80°C. Cells with Toray TGP-H-060 gas diffusion layer (GDL) with microporous layer (MPL) and different rib width were operated with different feed gas humidifications (under- and oversaturated) and current densities between 0.75 to 3.0 A/cm2. Based on the quantification of the local and average saturation, the distribution of water cluster size is analyzed. Different categories of the water cluster connectivity are defined and quantified. The analysis is complemented with numerical simulations of the permeability in the liquid phase of the GDL that is correlated to saturation for the different GDL domains. The numerical simulations of the pressure drop of liquid water flow from the catalyst layer toward the gas channels in channel-rib repetition units allows for conclusions on cluster growth mechanisms.
  • Reducing Mass Transfer Effects on the Kinetics of 5V HE-NCM Electrode Materials for Li-Ion Batteries
    Item type: Journal Article
    Villevieille, Claire; Gómez-Cámer, Juan Luis; Heβ, Michael; et al. (2014)
    Journal of the Electrochemical Society
  • Reversible Li-Intercalation through Oxygen Reactivity in Li-Rich Li-Fe-Te Oxide Materials
    Item type: Journal Article
    McCalla, Eric; Prakash, Annigere S.; Berg, Erik; et al. (2015)
    Journal of the Electrochemical Society
  • Electrocatalytic hydrogenation of indigo - Process optimization and scale-up in a flow cell
    Item type: Journal Article
    Roessler, Albert; Dossenbach, Otmar; Rys, Paul (2003)
    Journal of the Electrochemical Society
  • Investigation and Optimisation of Operating Conditions for Low-Temperature CO2 Reduction to CO in a Forward-Bias Bipolar-Membrane Electrolyser
    Item type: Journal Article
    Pribyl-Kranewitter, Bernhard; Beard, Alexandra; Schuler, Tobias; et al. (2021)
    Journal of the Electrochemical Society
    The most recent investigations of operating conditions in a forward-bias bipolar-membrane zero-gap electrolyser using a silver cathode catalyst for the reduction of CO2 to CO at low temperatures and near-ambient pressures are reported. First, the CO2 electrolyser performance was investigated as a function of cathode feed humidification and composition. The highest CO partial current density was 127 mA cm-2, which was obtained at an iR-corrected cell voltage of 2.9 V, a cathode feed humidification of 50%RH, CO2 feed concentration of 90% and a CO Faradaic efficiency of 93%. The cells were tested continuously for 12 h at 3 V and 8 h at 3.4 V cell voltage to investigate system stability. While Faradaic efficiencies were maintained during the measurements at 3.0 V, a shift in selectivity was observed at 3.4 V, while a deterioration in current densities occurred in both cases. Using a specially designed electrochemical cell with an integrated reversible hydrogen reference electrode, it was found that the cathode catalyst is the main responsible for the observed loss in performance. It was furthermore determined via post-mortem SEM and EDX investigations that cathode deterioration is caused by catalyst agglomeration and surface poisoning.
  • Aspects of the Surface Layer Formation on Li1+xMn2O4− during Electrochemical Cycling
    Item type: Journal Article
    Simmen, F.; Hintennach, A.; Horisberger, M.; et al. (2010)
    Journal of the Electrochemical Society
  • Tomographic Analysis and Modeling of Polymer Electrolyte Fuel Cell Unsupported Catalyst Layers
    Item type: Journal Article
    Ishikawa, Hiroshi; Henning, Sebastian; Herranz, Juan; et al. (2018)
    Journal of the Electrochemical Society
    Polymer electrolyte fuel cells (PEFCs) widespread commercialization is hindered by the devices’ limited durability, in terms caused by the corrosion of the carbon support used in the Pt-based PEFC catalysts. Using unsupported electrocatalysts could mitigate such durability issues, but little is known regarding the manner in which their processing into catalyst layers (CLs) affects pore size distribution (PSD) and PEFC performance. Thus, we have used a computational model to investigate the modes of agglomerate packing in CLs made from unsupported Pt3Ni nanochain ensembles (aerogels) or Pt black, and complemented this analysis with focused ion beam scanning electron microscopy tomography of corresponding real CLs. 3D structures, PSDs and tortuosities were obtained for real and computed CLs and were found to be in good agreement. The Pt black CL mainly exhibits large and straight pores (>100 nm wide), while the Pt3Ni aerogel CL mostly features small and twisted pores (< 100 nm wide) that cause the significantly poorer O2 mass transport (vs. Pt black) observed in PEFC experiments. Moreover, this modeling approach leads to key insights on the working principle of a filler material used for positively shifting the average PSD and improving the PEFC performance of the Pt3Ni CL.
  • Study of water balance in a polymer electrolyte fuel cell by locally resolved impedance spectroscopy
    Item type: Journal Article
    Schneider, Ingo A.; Kuhn, Holger; Wokaun, Alexander; et al. (2005)
    Journal of the Electrochemical Society
  • Electrochemical Characterization of La0.58Sr0.4Co0.2Fe0.8O3-delta Thin Film Electrodes Prepared by Pulsed Laser Deposition
    Item type: Journal Article
    Plonczak, Pawel; Sogaard, Martin; Bieberle-Hütter, Anja; et al. (2012)
    Journal of the Electrochemical Society
  • Modelling Study of Surface Reactions, Diffusion, and Spillover at a Ni/YSZ Patterned Anode
    Item type: Journal Article
    Vogler, Marcel; Bieberle-Hütter, Anja; Gauckler, Ludwig J.; et al. (2009)
    Journal of the Electrochemical Society
Publications 1 - 10 of 140