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

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

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

Mass distribution in a 33 kW PEMFC stacks :

Bipolar Plate :

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

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))

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.

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  0.016 mA/cm2 Compressive strength :  22 lb/in2 Density :  5 gm/cm2

Bipolar plate :

Bipolar plate :

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

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

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

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

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.

References: (1) A. Hermann, T. Chaudhuri and P. Spagnol (2005), “Bipolar plates for PEM fuel cells : A review”, International Journal of Hydrogen Energy, 30, 1297-1302. (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, 3717-3725.

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