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EXPERIMENT STUDIES
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Single PEM Fuel Cell Assembly
Current collector
Gas diffusion layer
Gasket
MEA
Gasket
End plate
Graphite flow-channel block
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Schematic of fuel cell operation
-
+
ee-
Hydrogen
Air (Oxygen)
H+
e-
H+
e-
Anode
H2
+
Membrane
e-
ee-
H+
Cathode
e-
2H+ + 2e-
O2+ 4H+ + 4eCatalyst (Pt)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
2H2O
Schematic of water transport in PEM fuel cell
Air
H2
Humidifier
Diffusion Layer
H+ (H2O)n drag
2 H 1 / 2O2 2e H 2O
H 2 2 H 2e
Pt
Pt
H2O diffusion
Membrane
H2O, H2
FCR Laboratory
Catalyst (Pt)
Dept. of Chemical Engineering
H2O, Air
University of South Carolina
Anode & Cathode inlet humidity data
Anode
Cathode
100
100
98
96
Humidification 90 oC
o
Humidification 90 C
80
Humidification 80 oC
Relative humidity (%)
Relative humidity (%)
90
94
92
Humidification 80 oC
90
88
86
70
Humidification 70 oC
Humidification 70 oC
84
82
60
80
50
100
150
200
Flow rate (cm 3/min)
FCR Laboratory
Dept. of Chemical Engineering
200
300
400
Flow rate (cm 3/min)
University of South Carolina
500
Schematic of the humidity chamber
Dry gas
Humid gas
DI water
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
PEM Fuel Cells Test station and data acquisition
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Actual Serpentine Flow Field
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Flow Diagram
Fuel Cell Test Station
Bypass
3 way valve
Hydrogen
3 way valve
Mass Flow Controller
Reformate
Heater
Anode Gas In
Thermocouple Controller
Humidity Bottle
Oxygen
Bypass
Mass Flow Controller
Air
Cathode Gas In
Heater
Thermocouple Controller
Humidity Bottle
Fuel Cell
Thermocouple Controller
Heater
Cathode Gas Out
Pressure
Gauge
Back Pressure
Regulator
Anode Gas Out
FCR Laboratory
Dept. of Chemical Engineering
Cathode Vent
Anode Vent
University of South Carolina
Schematic of water collection set up
Humidifier
Fuel Cell Tester
Thermocouple
Thermocouple
Beaker
Fuel Cell
Beaker
Ice bath
Balance
Balance
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Polarization curves for PEM fuel cell.
( Tcell = 70 oC, pressure(A/C) = 2/2 atm, Low stoic.)
1.0
0.9
Cell voltage (V)
0.8
0.7
T(A/C)=85/75 oC
0.6
0.5
T(A/C)=95/85 oC
0.4
0.3
0
1
2
3
4
5
6
7
8
9
10
Current (A)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Humidity effects on PEM fuel cell performance
(70 oC cell temperature, P(A/C): 2/2 atm, flow rate (A/C): 76/319 cm3/min
12
10
T A/C = 85/75 o C
C u rre n t (A )
8
T A/C = 75/65 o C
T A/C = 65/55 o C
6
T A/C = 95/85 o C
4
2
0
0
10
20
30
40
50
60
Tim e (hour)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Cell temperature effects on the performance at 0.6 V
( T(A/C) = 75 oC/Bypass, pressure(A/C) = 1/1 atm, flow rate(A/C) = 66/277 cm3/min)
12
10
8
Current (A)
Tcell = 65 oC
Tcell = 55 oC
6
Tcell = 75 oC
4
2
0
0
10
20
30
Time (hr)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
40
Water balance in PEM fuel Cell
Anode Water Balance (g/hr)
Cell
Temp.
(oC)
Cathode Water Balance (g/hr)
Overall
Current
density
(A/cm2)
Water
in
at
75oC
Wate
r out
Max.
water out
at Cell
Temp.
Cross
to
Cathod
e
Water in
w/o Hum.
Generation
Water
out
Max. water
out at Cell
Temp.
Cross from
Anode
% error
cross-over
water
55
0.47
1.18
0.67
0.38
0.51
0.00
1.56
2.01
2.69
0.45
13
65
0.59
1.18
0.42
0.54
0.76
0.00
1.97
2.68
4.73
0.71
7.7
75
0.31*
1.18
0.31
1.58
0.87
0.00
1.04*
1.90
9.15
0.86
2.2
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Flux of water
FCR Laboratory
T(A/C)
(oC)
TCell
(oC)
Current
density
(A/cm2)
Flux of
water
(g/s-cm2)
Mole H2O
/Moles H+
75/Bypass
55
0.47
1.44*10-5
0.16
75/Bypass
65
0.59
2.14*10-5
0.19
75/Bypass
75
0.31*
2.44*10-5
0.43*
Dept. of Chemical Engineering
University of South Carolina
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Schematic of PEM fuel cell with the pressure sensitive film
Current collector
Gas diffusion layer (E-Lat)
Gasket
Gasket
Pressure sensitive film
Graphite flow-channel block
FCR Laboratory
Bolts
MEA
Dept. of Chemical Engineering
End plate
Bolt
holes
University of South Carolina
Pressure inside fuel cell as measured by pressure sensitive film.
(1 psi = 1 lbf/in2, 1 mil = 2.54 x10-5 m)
Gasket Type
Incompressibl
e
(7 mils)
Diffusion Layer
Film Type
Torque (in-lbf/bolt)
100
125
150
TORAY (8 mils)
Super Low
234 psi
261 psi
302 psi
CARBEL-TORAY
Low
1065 psi
1247 psi
1270 psi
Low
1214 psi
1349 psi
> 1400 psi
(11 mils)
E-LAT
(20 mils)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Effect of torque on the cell polarization & power density with an E-LAT
(Tcell = 70 oC, T(A/C) = 85/75 oC, P(A/C) = 15/15 psig)
0.6
1.0
0.9
0.5
0.8
100 in-lb/bolt
0.7
125 in-lb/bolt
0.3
150 in-lb/bolt
0.6
0.2
0.5
100 in-lb/bolt
125 in-lb/bolt
0.1
0.4
150 in-lb/bolt
0.0
0.3
-0.1
0.2
0.0
0.2
0.4
0.6
1.0
0.8
1.2
1.4
Current density (A/cm2)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Power density (W/cm 2)
Cell voltage (V)
0.4
Effect of torque on the cell polarization & power density
with TORAYTM & CARBEL
(Tcell = 70 oC, T(A/C) = 85/75 oC, P(A/C) = 15/15 psig)
1.0
0.5
0.9
0.4
Cell voltage (V)
0.3
0.7
125 in-lb/bolt
150 in-lb/bolt
100 in-lb/bolt
0.6
0.2
0.5
125 in-lb/bolt
0.1
150 in-lb/bolt
0.4
-0.0
0.3
100 in-lb/bolt
0.2
-0.1
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
Current density (A/cm2)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Power density (W/cm 2)
0.8
Effect of torque on the cell polarization & power density with a TORAYTM
(Tcell = 70 oC, T(A/C) = 85/75 oC, P(A/C) = 15/15 psig)
1.0
0.5
0.9
0.4
0.3
0.7
100 in-lb/bolt
150 in-lb/bolt
0.6
125 in-lb/bolt
0.2
0.5
100 in-lb/bolt
0.4
150 in-lb/bolt
0.3
0.1
125 in-lb/bolt
0.0
0.2
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
Current density (A/cm2)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Power density (W/cm 2)
Cell voltage (V)
0.8
Comparison of power densities for three diffusion layers
at torque 125 in-lbf/bolt
0.6
0.5
Power density (W/cm 2)
0.4
E-lat
0.3
Toray
Carbel100-Toray
0.2
0.1
0.0
-0.1
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Current density (A/cm2)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Effect of humidity & compression pressure on
the cell polarization & power density at Tcell = 50 oC
1.0
0.6
572 psi
T(A/C) = 75/65 oC
0.9
0.5
Cell voltage (V)
0.4
308 psi
0.7
T(A/C) = 75/65 oC
802 psi
0.6
T(A/C)=95/85 oC
T(A/C)=65/55 oC
572 psi
802 psi
0.5
0.3
802 psi
0.2
T(A/C) = 75/65 oC
T(A/C)=95/85 oC
0.4
0.1
0.3
802 psi
308 psi
T(A/C)=65/55 oC
0.0
T(A/C) = 75/65 oC
0.2
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Current density (A/cm2)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Power density (W/cm 2)
0.8
Effect of humidity on the cell polarization for
Tcell = 50 oC and compression pressure 308 psi.
1.0
0.9
Cell voltage (V)
0.8
0.7
0.6
T(A/C)=65/55 oC
T(A/C)=75/65 oC
0.5
0.4
T(A/C)=95/85 oC
T(A/C)=85/75 oC
0.3
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
Current density (A/cm2)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Example water collection data for the anode side
(Tcell = 50 oC, T(A/C) = 75/65 oC & compression pressure = 802 psi )
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Water balance in PEM fuel cell
(Cell voltage 0.5 V, cell temp. 50 oC, compression pressure 802 psi)
Hum.
temp.
(oC)
Current
density
(A/cm2)
Anode water balance (g/min)
Cathode water balance (g/min)
Overall
accum.
(g/min)
Water
in
Water
out
Accum.
at
anode
Maximum
water out at
cell temp.
Water
in
Gen.
Water
out
Accum.
at
cathode
Maximum
water out at
cell temp.
65/55
0.89
0.012
4
0.020
8
-0.0084
0.0017
0.0379
0.0499
0.0773
0.0106
0.0324
0.0022
75/65
0.86
0.022
7
0.032
4
-0.0097
0.0017
0.0682
0.0483
0.0986
0.0179
0.0314
0.0081
85/75
0.78
0.047
2
0.057
3
-0.0101
0.0017
0.1152
0.0439
0.1402
0.0189
0.0294
0.0088
95/85
0.75*
0.119
8
0.167
4
-0.0475
0.0015
0.2474
0.0419
0.2412
0.0481
0.0275
0.0005
(*Performance degrading at 95/85 oC requires data to be estimated using an average current).
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Water balance in PEM fuel cell
(Cell voltage 0.5 V, cell temp. 50 oC, compression pressure 308 psi)
Hum.
temp.
(oC)
Current
density
(A/cm2)
Anode water balance (g/min)
Cathode water balance (g/min)
Overall
accum.
(g/min)
Water
in
Water
out
Accum
. at
anode
Maximum
water out at
cell temp.
Water
in
Gen.
Water
out
Accum.
at
cathode
Maximum
water out at
cell temp.
65/55
0.87
0.011
9
0.028
3
-0.0164
0.0015
0.0361
0.0486
0.0568
0.0279
0.0310
0.0115
75/65
0.89
0.022
3
0.039
4
-0.0171
0.0014
0.0674
0.0497
0.0750
0.0422
0.0309
0.0251
85/75
0.85
0.050
4
0.060
2
-0.0098
0.0016
0.1242
0.0477
0.1133
0.0586
0.0310
0.0488
95/85
0.82*
0.132
9
0.176
5
-0.0436
0.0016
0.2743
0.0461
0.2116
0.1088
0.0303
0.0651
(*Performance degrading at 95/85 oC requires data to be estimated using an average current).
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
+
+
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
-
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Schematic of Air Bleed System
Flow meter
Air
Filter
Check valve
H2 /CO2 /H2O (out)
FCR Laboratory
O2 /H2O (out)
Dept. of Chemical Engineering
University of South Carolina
Performance comparison between CARBEL CLTM and
Single Side ELATTM GDM for 500 ppm CO.
1.0
0.9
0.8
CARBEL CL
Cell voltage (V)
0.7
Neat H2
0.6
0.5
0.4
Single Side ELAT
Single Side ELAT
w/o air bleed
air bleed (5 %)
0.3
CARBEL CL
Single Side ELAT
w/o air bleed
Neat H2
CARBEL CL
air bleed (5 %)
0.2
0.1
0.0
0
200
400
600
800
1000
1200
1400
1600
1800
Current density (mA/cm2)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Performance comparison between CARBEL CLTM and
Single Side ELATTM GDM for 3000 ppm CO.
1.0
0.9
0.8
CARBEL CL
Neat H2
Cell voltage (V)
0.7
SSE
0.6
air bleed (15 %)
0.5
0.4
CARBEL CL
SSE
w/o air bleed
w/o air bleed
0.3
CARBEL CL
SSE
air bleed (15 %)
Neat H2
0.2
0.1
0.0
0
200
400
600
800
1000
1200
1400
1600
1800
Current density (mA/cm2)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Anode overpotentials (calculated by difference) due to CO poisoning for
CARBEL CLTM and Single Side ELATTM GDM at different conditions
0.5
Anode Overvoltage (EH2 - EH2/CO)
0.4
0.3
0.2
0.1
0.0
101
2
3
4
5
6 7 8
102
2
3
4
5
6 7 8
103
2
3
4
5
6 7 8
104
Current density (mA/cm2)
(dashed lines) 3000 ppm CO/H2; (solid lines) 500 ppm CO/H2;
(■) SSE w/ air bleed; (□) SSE w/o air bleed; (●) CARBEL CL w/ air bleed; (○) CARBEL CL w/o air bleed.
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Transient performance with 50 and 500 ppm CO at 600 mA/cm2 with
CARBEL CL GDM.
0.8
-0.323
0.7
(V/min) -0.332 -0.417 -0.400 -0.417 -0.400
Cell voltage (V)
0.6
0.5
0.4
Neat H2
50 ppm CO/H2 (Base)
0.056 0.051 0.053 0.053 0.059
0.056
Base Base Base Base Base
Base
Neat H2
0.3
500 ppm CO/H2 for 5 min.
0.2
0.1
0.0
0
1
2
3
4
5
6
7
Time (hr)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
8
Transient performance with 50 and 500 ppm CO at 600 mA/cm2
during air-bleed with CARBEL CL GDM.
0.9
0.8
500 ppm CO/H2 for 5 min.
Cell voltage (V)
Neat H2
50 ppm CO/H2 (Base)
Base
Base
500 ppm CO/H2 for 5 min.
Base
Base
Base
Base
Neat H2
Base
0.7
Air bleeding (5%)
0.6
0.5
0.4
0
1
2
3
4
5
6
7
8
Time (hr)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Transient performance with neat hydrogen and 3000 ppm CO at
600 mA/cm2 with CARBEL CL GDM.
0.8
0.7
0.6
Cell voltage (V)
- 0.971
0.5
-1.410
-1.413
-1.437
-1.437
(V/min)
0.088
0.4
0.3
-1.437
0.092
0.099
0.096
0.094
0.098
(V/min)
Neat H 2 (Base)
Base
Base
Base
Base
Base
Neat H 2 (Base)
0.2
3000 ppm CO/H2 for 5 min.
3000 ppm CO/H2 for 5 min.
0.1
0.0
0
1
2
3
4
Time (hr)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
5
Transient performance with neat hydrogen and 3000 ppm CO at
600 mA/cm2 during air-bleed withCARBEL CL GDM.
0.9
0.8
Air bleeding (15 %)
Cell voltage (V)
0.7
0.6
-0.115
0.5
-0.134
-0.125
-0.128
-0.134
-0.127
(V/min)
0.4
Neat H2
0.341
0.323
0.357
0.323
0.358
Neat H2
Neat H2
Neat H2
Neat H2
Neat H2
0.334
Neat H2
0.3
3000 ppm CO/H2 for 5 min.
0.2
3000 ppm CO/H2 for 5 min.
0.1
0
1
2
3
4
5
Time (hr)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
Transient performance with 50 and 3000 ppm CO at
600 mA/cm2 with Single-Sided ELAT GDM.
0.8
-0.729
0.7
(V/min)
-0.738
-0.746
-0.742
-0.752
-0.796
Cell voltage (V)
0.6
0.5
0.4
0.075
0.069
0.073
0.070
0.076
0.067
Base
Base
Base
Base
Base
Base
0.3
Neat H2 50 ppm CO/H2 (Base)
Neat H2
0.2
3000 ppm CO/H2 for 5 min.
3000 ppm CO/H2 for 5 min.
0.1
0.0
0
1
2
3
4
5
Time (hr)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
6
Transient performance with 50 and 3000 ppm CO at
600 mA/cm2 during air-bleed with Single-Sided ELAT GDM.
0.9
Air bleeding (15 %)
0.8
-0.109
(V/min) -0.173 -0.171 -0.174 -0.168 -0.179
Cell voltage (V)
0.7
0.6
0.5
0.4
Neat H2
50 ppm CO/H2 (Base)
0.186
0.196 0.180
0.192
0.188
Base
Base
Base
Base
Base
0.181
50 ppm CO/H2 (Base)
Neat H2
0.3
0.2
3000 ppm CO/H2
3000 ppm CO/H2
for 5 min.
for 5 min.
0.1
0
1
2
3
4
5
6
7
Time (hr)
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
8
-Humidification Effect:
The results show how the current changed with inlet humidity & cell temperature
-Clamp Torque Effect:
Optimal compression pressure obtained.
This optimum was explained in terms of changes in the porosity & conductivity.
-Interaction between compression pressure & humidity:
The performance at the higher compression pressure is sensitive with changing
humidity condition.
Water balance data show the water transports during the fuel cell operation.
-CO poisoning on the catalyst:
The results show the CO effect on the performance of PEM Fuel cell.
-The experiment data provided in useful to verify mathematical model and their
prediction for PEM Fuel cell performance.
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina
FCR Laboratory
Dept. of Chemical Engineering
University of South Carolina