Highly filled graphite polybenzoxazine composites for an application as bipolar plates in fuel cells

Abstract

Highly filled graphite polybenzoxazine composites as bipolar plate material for polymer electrolyte membrane fuel cell (PEMFC) are developed. At the maximum graphite content of 80 wt % (68 vol %), storage modulus was increased from 5.9 GPa of the neat polybenzoxazine matrix to 23 GPa in the composite. Glass transition temperatures (T g ) of the composites were ranging from 176 C to 195 C and the values substantially increased with increasing the graphite contents. Thermal conductivity as high as 10.2 W/ mK and electrical conductivity of 245 S cm 21 were obtained in the graphite filled polybenzoxazine at its maximum graphite loading. The obtained properties of the graphite filled polybenzoxazine composites exhibit most values exceed the United States department of energy requirements for PEMFC applications.

Highly filled graphene‐benzoxazine composites as bipolar plates in fuel cell applications

“…Those values reduced from 336 J/g of the neat polybenzoxazine to 330 J/g of molding compound containing 10 wt% of graphene and to the value as low as 133 J/g of the molding compound containing 60 wt% of graphene. This expected phenomenon was related to the decreasing amount of benzoxazine resin in the molding compounds [10]. Figure 1b exhibited the DSC thermograms of graphene-filled benzoxazine molding compound at 10 wt% of graphene loading cured at 200 C at various curing time.…”

“…Interestingly, the curing peak maximum of the molding compounds evidently shifted to lower temperature with higher amount of graphene loading. The positions of exothermic peaks of 10,20,30,40,50, and 60 wt% of graphene content in benzoxazine molding compound were 218, 212, 211, 209, 202, and 196 C, respectively. The results indicated that graphene might act as a catalyst for oxazine-ring opening reaction thus alleviated the curing condition in terms of energy consumption of the polymerization reaction.…”

“…5 and their actual densities were calculated according to Eq. 1 based on the reported densities of polybenzoxazine and graphene are 1.19 and 2.20 g/cm 3 , respectively [2,10].…”

“…The graphene-filled polybenzoxazine composites were prepared with graphene loadings of 0, 10,20,30,40,50 and 60 wt% to yield molding compounds. The graphene was firstly dried at 110 C for 24 h in an air-circulated oven until a constant weight was achieved and was then kept in a desiccator at room temperature.…”

Recent Progress on the Key Materials and Components for Proton Exchange Membrane Fuel Cells in Vehicle Applications

“…Machining is usually employed to fabricate the flow channels in the BPPs. Machining graphite into complex designs is highly expensive and time-consuming, and therefore makes it unpractical for the full scale commercialization of fuel cells [166,167].…”