Ultra‐thin carbon/silicon carbide composite bipolar plate for advanced fuel cells

Abstract

AbstractThe first cut results on the development of ultra‐thin, low gas permeable, easily machineable, high electrical conductivity and high mechanical strength bipolar plate made up of carbon reinforced ceramic matrix are reported for the strategic application. Short carbon fiber reinforced silicon carbide matrix composite is fabricated by chopping continuous carbon fibers into discrete length, exfoliating and dispersing the exfoliated carbon fibers in silicon carbide powder and finally hot‐pressing to make the composite. Three compacts containing exfoliated carbon fiber contents of 20, 30, 50 vol. % in silicon carbide matrix are prepared and characterized for electrical, thermal, gas permeability, density, and mechanical properties. The composite plates with exfoliated carbon fiber vol. % of 50, offer excellent electrical conductivity, flexural and compressive strengths and gas permeability of 2.2 × 10‐7 cm‐3 cm‐2 s‐1. Carbon/silicon carbide plate shows 37.5 % and 4.7 % lower volume and weight, respectively on comparing with the best reported data of carbon/polymer composite plate. Competency of the material for bipolar plate fabrication is tested and found that the ceramic carbon composite may open up the new horizon for the fabrication of ultra‐thin bipolar plates for strategic applications.