1. Dr. Jatrawan Phumchusak And Miss. Somruthai Tunma
Preparation of Electrical Conductive ABS Composite for Bipolar Plates in PEM Fuel Cell
Dr. Jatrawan Phumchusak
And
Miss. Somruthai Tunma

2. conductive polymer composite bipolar plate
Aim to prepare the electrical
conductive polymer composite bipolar plate
in order to reduce the manufacturing cost
of PEMFC

3. Polymer Electrolyte Membrane Fuel Cell ; PEMFC
Introduction :
Polymer Electrolyte Membrane Fuel Cell ; PEMFC
clean and potential energy sorce
high production cost

4. Mass distribution in a 33 kW PEMFC stacks :

5. Bipolar Plate :

6. Classification of materials for BPs used in PEM fuel cell :
Non-metal : Non-porous graphite plates
Metals : Metal plates
Composites : - Metal based
- Carbon based :
- Thermoplastics
- Thermosets

7. Requirements for Bipolar Plates :
Electrical conductivity :
- DOE (the U.S.Department of Energy) > 100 S/cm
- F.N.Büchi ≥ 10 S/cm
(Development of a Bipolar Element for PE- fuel cell, demonstration in a 6 kW stack)
- B.W.Choi ≥ 2.5 S/cm (higher than gas diffusion electrode)
(J.Hydrogen energy 21 (1996))

8. The BPs have the following functions to perform :
To distribute the fuel and oxidant within the
cell.
To facilitate water management within the cell.
To separate individual cells in the stack.
To carry current away from the cell.
- To facilitate heat management.

9. Properties of BP :
Electrical conductivity : plate resistance  0.01 cm 2
Thermal conductivity : as high as possible
Hydrogen/gas permeability :  10-4 cm3/scm2
Corrosion resistance : corrosion rate  mA/cm2
Compressive strength :  22 lb/in2
Density :  5 gm/cm2

10. Bipolar plate :

11. Bipolar plate :

12. Methodology : ABS matrix Graphite powder Carbon black powder
Carbon fiber
2-rolls mixer
Measure the in-plane electrical resistance
by using the digital multimeter
Hot pressing machine

13. Result:
Table 1,2 : Electrical properties of ABS - Graphite composites.
ABS–Graphite Composites
Conductivity, 
S/cm
60 : 40
1.77  10-2
50 : 50
3.73  10-3
40 : 60
2.30  10-1
30 : 70
3.67
25 : 75
7.72
20 : 80
13.00
ABS–Graphite Composites
Conductivity, 
S/cm
60 : 40
8.40  10-3
50 : 50
5.00  10-2
40 : 60
2.10  10-1
30 : 70
2.11
Note : pure graphite
Note : mixed graphite

14. Note : CB – Carbon black , G - Graphite
Result :
Table 3 : Electrical properties of carbonaceous fillers - ABS composites.
ABS : CB : G
Conductivity, 
S/cm
25 : 5 : 70
8.16
25 : 10 : 65
9.28
30 : 20 : 50
12.95
Note : CB – Carbon black , G - Graphite

15. Table 4 : The effect of CF length : longer CF higher conductivity
ABS: CF : G Composites
Conductivity, 
S/cm
ABS : CF1 : G
40 : 20 : 40
0.10
ABS : CF2 : G
0.30
- CF1 length = 3 mm
- CF2 length = 5 mm
The effect of CF length :
longer CF higher conductivity

16. Discussion and Conclusion :
- Add carbon fiber to improve the conductivity of ABS composites.
- The effect of content and composition of fillers and the incorporation of fillers including the length of carbon fiber on the electrical properties of polymer composite were studied.

17. References:
(1) A. Hermann, T. Chaudhuri and P. Spagnol (2005), “Bipolar plates for PEM fuel cells : A review”, International Journal of Hydrogen Energy, 30,
(2) H-C. Kuan, C-C. M. Ma, K. H. Chen and S-M. Chen (2004), “Preparation, electrical, mechanical and thermal properties of composite bipolar plate for a fuel cell”, Journal of Power Sources, 134, 7-14.
(3) W. Thongruang, R. J. Spontak and C. M. Balik (2002), “Bridged double percolation in conductive polymer composites: an electrical conductivity, morphology and mechanical property study”, Polymer, 43,

18. Acknowledgement :
งานวิจัยนี้ ได้รับการสนับสนุนเงินทุนในการทำวิจัยบางส่วนจากสำนักงานนโยบายและแผนพลังงาน (สนพ.) ส่วนอนุรักษ์พลังงานและพลังงานหมุนเวียน ประเภทงานวิจัยที่เกี่ยวข้องกับพลังงานทดแทน ปีงบประมาณ 2548