1. University of South Carolina FCR Laboratory Dept. of Chemical Engineering EXPERIMENT STUDIES

2. University of South Carolina FCR Laboratory Dept. of Chemical Engineering

3. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Gas (H 2 ) out Gas (H 2 ) in Gas (Air) out Gas (Air) in End plate Current collector Gasket MEA Gasket Gas diffusion layer Graphite flow-channel block Single PEM Fuel Cell Assembly

4. University of South Carolina FCR Laboratory Dept. of Chemical Engineering

5. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Catalyst (Pt) e-e-e-e-e-e- HydrogenAir (Oxygen) - + - Anode 2H + + 2e - H2H2 Cathode O 2 + 4H + + 4e - 2H 2 O e-e- e-e- e-e-e-e-e-e- H+H+H+H+H+H+ Membrane + Schematic of fuel cell operation

6. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Schematic of water transport in PEM fuel cell Membrane Catalyst (Pt) H + (H 2 O) n drag H 2 O diffusion Humidifier Diffusion Layer Air H2H2 H 2 O, H 2 H 2 O, Air

7. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Anode & Cathode inlet humidity data

8. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Dry gas Humid gas DI water Schematic of the humidity chamber

9. University of South Carolina FCR Laboratory Dept. of Chemical Engineering

10. University of South Carolina FCR Laboratory Dept. of Chemical Engineering PEM Fuel Cells Test station and data acquisition

11. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Actual Serpentine Flow Field

12. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Flow Diagram

13. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Schematic of water collection set up

14. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Polarization curves for PEM fuel cell. ( T cell = 70 o C, pressure(A/C) = 2/2 atm, Low stoic.)

15. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Humidity effects on PEM fuel cell performance (70 o C cell temperature, P(A/C): 2/2 atm, flow rate (A/C): 76/319 cm 3 /min

16. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Cell temperature effects on the performance at 0.6 V ( T(A/C) = 75 o C/Bypass, pressure(A/C) = 1/1 atm, flow rate(A/C) = 66/277 cm 3 /min)

17. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Cell Temp. ( o C) Current density (A/cm 2 ) Anode Water Balance (g/hr) Cathode Water Balance (g/hr)Overall Water in at 75 o C Wate r out Max. water out at Cell Temp. Cross to Cathod e Water in w/o Hum. GenerationWater out Max. water out at Cell Temp. Cross from Anode % error cross-over water 550.471.18 0.67 0.380.510.001.562.012.690.4513 650.591.18 0.42 0.540.760.001.972.684.730.717.7 750.31*1.18 0.31 1.580.870.001.04*1.909.150.862.2 Water balance in PEM fuel Cell

18. University of South Carolina FCR Laboratory Dept. of Chemical Engineering T(A/C) ( o C) T Cell ( o C) Current density (A/cm 2 ) Flux of water (g/s-cm 2 ) Mole H 2 O /Moles H + 75/Bypass550.471.44*10 -5 0.16 75/Bypass650.592.14*10 -5 0.19 75/Bypass750.31*2.44*10 -5 0.43* Flux of water

19. University of South Carolina FCR Laboratory Dept. of Chemical Engineering

20. University of South Carolina FCR Laboratory Dept. of Chemical Engineering

21. University of South Carolina FCR Laboratory Dept. of Chemical Engineering End plate Current collector Gasket MEA Gasket Gas diffusion layer (E-Lat) Graphite flow-channel block Pressure sensitive film Bolt holes Bolts Schematic of PEM fuel cell with the pressure sensitive film

22. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Gasket TypeDiffusion LayerFilm TypeTorque (in-lb f /bolt) 100125150 Incompressibl e (7 mils) TORAY  (8 mils) Super Low234 psi261 psi302 psi CARBEL  -TORAY  (11 mils) Low1065 psi1247 psi1270 psi E-LAT  (20 mils) Low1214 psi1349 psi> 1400 psi Pressure inside fuel cell as measured by pressure sensitive film. (1 psi = 1 lb f /in 2, 1 mil = 2.54 x10 -5 m)

23. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Effect of torque on the cell polarization & power density with an E-LAT  (Tcell = 70 o C, T(A/C) = 85/75 o C, P(A/C) = 15/15 psig)

24. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Effect of torque on the cell polarization & power density with TORAY TM & CARBEL  (Tcell = 70 o C, T(A/C) = 85/75 o C, P(A/C) = 15/15 psig)

25. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Effect of torque on the cell polarization & power density with a TORAY TM (Tcell = 70 o C, T(A/C) = 85/75 o C, P(A/C) = 15/15 psig)

26. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Comparison of power densities for three diffusion layers at torque 125 in-lbf/bolt

27. University of South Carolina FCR Laboratory Dept. of Chemical Engineering

28. University of South Carolina FCR Laboratory Dept. of Chemical Engineering

29. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Effect of humidity & compression pressure on the cell polarization & power density at T cell = 50 o C

30. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Effect of humidity on the cell polarization for T cell = 50 o C and compression pressure 308 psi.

31. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Example water collection data for the anode side (Tcell = 50 o C, T(A/C) = 75/65 o C & compression pressure = 802 psi )

32. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Hum. temp. ( o C ) Current density (A/cm 2 ) 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 0.00170.03790.04990.07730.01060.03240.0022 75/65 0.86 0.022 7 0.032 4 -0.0097 0.00170.06820.04830.09860.01790.03140.0081 85/75 0.780.047 2 0.057 3 -0.0101 0.00170.11520.04390.14020.01890.02940.0088 95/85 0.75*0.119 8 0.167 4 -0.0475 0.00150.24740.04190.24120.04810.02750.0005 Water balance in PEM fuel cell (Cell voltage 0.5 V, cell temp. 50 o C, compression pressure 802 psi) (*Performance degrading at 95/85 o C requires data to be estimated using an average current).

33. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Hum. temp. ( o C ) Current density (A/cm 2 ) 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 0.00150.03610.04860.05680.02790.03100.0115 75/65 0.89 0.022 3 0.039 4 -0.0171 0.00140.06740.04970.07500.04220.03090.0251 85/75 0.850.050 4 0.060 2 -0.0098 0.00160.12420.04770.11330.05860.03100.0488 95/85 0.82*0.132 9 0.176 5 -0.0436 0.00160.27430.04610.21160.10880.03030.0651 Water balance in PEM fuel cell (Cell voltage 0.5 V, cell temp. 50 o C, compression pressure 308 psi) (*Performance degrading at 95/85 o C requires data to be estimated using an average current).

34. University of South Carolina FCR Laboratory Dept. of Chemical Engineering

35. University of South Carolina FCR Laboratory Dept. of Chemical Engineering - - + +

36. University of South Carolina FCR Laboratory Dept. of Chemical Engineering

37. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Schematic of Air Bleed System H 2 /CO/H 2 O (in) H 2 /CO 2 /H 2 O (out)O 2 /H 2 O (out) O  /H 2 O (in) Check valve Filter Flow meter Air

38. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Performance comparison between CARBEL CL TM and Single Side ELAT TM GDM for 500 ppm CO.

39. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Performance comparison between CARBEL CL TM and Single Side ELAT TM GDM for 3000 ppm CO.

40. University of South Carolina FCR Laboratory Dept. of Chemical Engineering (dashed lines) 3000 ppm CO/H 2 ; (solid lines) 500 ppm CO/H 2 ; (■) SSE w/ air bleed; (□) SSE w/o air bleed; (●) CARBEL CL w/ air bleed; (○) CARBEL CL w/o air bleed. Anode overpotentials (calculated by difference) due to CO poisoning for CARBEL CL TM and Single Side ELAT TM GDM at different conditions

41. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Transient performance with 50 and 500 ppm CO at 600 mA/cm 2 with CARBEL  CL GDM.

42. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Transient performance with 50 and 500 ppm CO at 600 mA/cm 2 during air-bleed with CARBEL  CL GDM.

43. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Transient performance with neat hydrogen and 3000 ppm CO at 600 mA/cm 2 with CARBEL  CL GDM.

44. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Transient performance with neat hydrogen and 3000 ppm CO at 600 mA/cm 2 during air-bleed withCARBEL  CL GDM.

45. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Transient performance with 50 and 3000 ppm CO at 600 mA/cm 2 with Single-Sided ELAT  GDM.

46. University of South Carolina FCR Laboratory Dept. of Chemical Engineering Transient performance with 50 and 3000 ppm CO at 600 mA/cm 2 during air-bleed with Single-Sided ELAT  GDM.

47. University of South Carolina FCR Laboratory Dept. of Chemical Engineering -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.

48. University of South Carolina FCR Laboratory Dept. of Chemical Engineering