Fabrication of electrically conductive polymer composites for bipolar plate by two-step compression molding technique

Authors

  • Kwi Chol Li,

    1. Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai, China
    2. Institute of Electronic Materials, Kim Il-sung University, Pyongyang, The Democratic People's Republic of Korea
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  • Kun Zhang,

    1. Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai, China
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  • Guozhang Wu

    Corresponding author
    • Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai, China
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Correspondence to: G. Wu (E-mail: wgz@ecust.edu.cn; wugz09@yahoo.cn)

ABSTRACT

Electrically conductive polymer composites for bipolar plate were fabricated by two-step compression molding technique. Raw materials consisted of natural graphite flakes (G), expanded graphite (EG), carbon black (CB), and phenol resin (PF). The G/EG/CB/PF composites were first compressed at a temperature lower than curing point (100°C) and then cured at a high temperature above curing point (150°C) and high pressure (10 MPa). Results showed that G and EG are oriented in the direction parallel to the composite plate surface. CB is dispersed not only in the phenol resin matrix but also in the packing and porous space of G and EG. The addition of EG and CB significantly increases number of the electrical channels and thus enhances the electrical conductivity of the composite. Under optimal conditions, electrical conductivity and flexural strength of the composite were 2.80 × 104 S/m and 55 MPa, respectively, suggesting that the dipolar plates prepared by two-step compression molding technique are adequate to meet the requirement of proton exchange membrane fuel cells. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2296–2302, 2013

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