International Journal of Hydrogen Energy, Vol.43, No.48, 21918-21927, 2018
Structural optimization of graphite for high-performance fluorinated ethylene-propylene composites as bipolar plates
This paper presents a novel method of structural optimization by using graphite particles ranging in size from 35 to 500 mu m to fabricate conductive fluorinated ethylene-propylene composites for high-temperature bipolar plates. To investigate the effects of dispersion and packing density, the large graphite particles were decorated with fluorinated ethylene-propylene powders by ball milling, and the master batch of well-dispersed small graphite particles and polymer master batch was mixed with large graphite particles. The resulting fluorinated ethylene-propylene/graphite composite bipolar plates, which contained 65 wt% graphite, exhibited high electrical conductivity of 550 S cm(-1). In particular, by modulating the electrical transportation paths between the large graphite particles with the well-dispersed fluorinated ethylene-propylene/ graphite master batch, the orientation and dispersion of the graphite particles in the matrix resulted in enhanced electrical conductivity and mechanical properties. The preparation of structurally optimized fluorinated ethylene-propylene/graphite composite bipolar plates with well-dispersed graphite particles of different sizes provides a robust and scalable strategy for realizing high-performance and large-area bipolar plates. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:Graphite;Fluorinated ethylene-propylene;Bipolar plate;Particle size;Twin-screw extruder;Compression molding