The microporous layer (MPL) is a key component of polymer electrolyte membrane fuel cells (PEM-FCs), and it is in charge of the gas and water management at the electrode-gas diffusion layer (GDL) interfaces. A MPL was prepared and coated onto two different commercial GDLs: a carbon paper (woven-non-woven (WNW)) and a carbon cloth (CC). Electrical performances of the so-obtained gas diffusion media (GDM), i.e., GDL coated with the MPL, were investigated in single cell testing (steady-state polarization curves) using a Nafion® catalyst coated membrane with a platinum loading of $0.5 mg/cm2$ both for the anode and the cathode. Moreover, in order to better understand the polarization phenomena during the running of the FC, impedance spectroscopy was carried out in galvanostatic mode at different current densities. In particular, the effect of the air relative humidity (RH 100%, 80%, and 60%) was investigated, while the hydrogen was fed always fully humidified (100%). The WNW substrate has demonstrated to be superior to CC in a vast range of current densities (from open circuit voltage to $0.8 A/cm2$). However, at high current density, the WNW GDM has some problems in water management.

1.
Frenette
,
G.
, and
Forthoffer
,
D.
, 2009, “
Economic & Commercial Viability of Hydrogen Fuel Cell Vehicles From an Automotive Manufacturer Perspective
,”
Int. J. Hydrogen Energy
0360-3199,
34
, pp.
3578
3588
.
2.
Barbir
,
F.
, 2005,
PEM Fuel Cells: Theory and Practice
,
Elsevier
,
Oxford, UK
.
3.
Wee
,
J. -H.
, 2007, “
Applications of Proton Exchange Membrane Fuel Cell Systems
,”
Renewable Sustainable Energy Rev.
1364-0321,
11
, pp.
1720
1738
.
4.
Mishra
,
V.
,
Yang
,
F.
, and
Pitchumani
,
R.
, 2004, “
Measurement and Prediction of Electrical Contact Resistance Between Gas Diffusion Layers and Bipolar Plate for Applications to PEM Fuel Cells
,”
Transactions of the Asme
,
1
(
1
), pp.
2
9
.
5.
Gallo Stampino
,
P.
,
Cristiani
,
C.
,
Dotelli
,
G.
,
Omati
,
L.
,
Zampori
,
L.
,
Pelosato
,
R.
, and
Guilizzoni
,
M.
, 2009, “
Effect of Different Substrates, Inks Composition and Rheology on Coating Deposition of Microporous Layer (MPL) for PEM-FCs
,”
Catal. Today
0920-5861,
147
, pp.
S30
S35
.
6.
Yuan
,
X.
,
Wang
,
H.
,
Colin Sun
,
J.
, and
Zhang
,
J.
, 2007, “
AC Impedance Technique in PEM Fuel Cell Diagnosis—A Review
,”
Int. J. Hydrogen Energy
0360-3199,
32
, pp.
4365
4380
.