Effect of rheology controller agent addition to Micro-Porous Layers on PEMFC performances

• Published in: Solid state ionics Vol. 216; pp. 73 - 77
• Main Authors: Latorrata, S., Stampino, P. Gallo, Amici, E., Pelosato, R., Cristiani, C., Dotelli, G.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 28.05.2012
• Subjects: Carbon; Carboxymethylcellulose; Density; Dispersions; Doctors; Electrochemical impedance spectroscopy; Gas diffusion; Gas diffusion layer; Micro-porous layer; Polymer electrolyte membrane fuel cell; Rheology; Spectra; Polymer electrolyte membrane fuel cell; Gas diffusion layer; Carboxymethylcellulose; Micro-porous layer; Electrochemical impedance spectroscopy
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/j.ssi.2012.03.030

Formulations of carbon-based inks for doctor blade applications were considered and the use of Carboxymethylcellulose (CMC) as rheology modifier and suspension stabilizer was proposed. Rheological measurement evidenced that CMC addition guarantees a good dispersion of the carbon powder which results in a higher stability of the ink. The electrical performances of Gas Diffusion Layer (GDL) coated with Micro-Porous Layers (MPLs) prepared with and without CMC were compared. A single PEMFC was used to assess the properties of these GDLs: electrochemical performances were tested in terms of I–V curves and of AC Electrochemical Impedance Spectroscopy (EIS) of the running cell. CMC-containing GDLs showed improved performances when the cell was operated at 80°C and RH 80–60. Analysis of the EIS spectra demonstrated that, at high Current Density (CD), the CMC-based GDLs suffer for water management. Such a behavior was ascribed to a hydrophilic character of the GDL due to residual amounts of CMC in MPL coating. ► Carboxymethylcellulose as rheology controller agent in inks formulation for MPLs in PEMFCs GDLs. ► Carboxymethylcellulose improves rheological features of the inks. ► CMC-based MPLs reduce FCs ohmic resistance. ► CMC-based MPLs improve FC electrochemical performance at high temperature and low humidity.