Polymer Electrolyte Fuel Cell (PEFC) is an environmentally friendly device that generates electricity with zero emissions. A constitutive part of PEFCs is the bipolar plate (BP), which offers mechanical support and distributes its reactant gases. In relation, manufacturing electrically conductive BPs at low cost is needed to position PEFC technology on the market. This work summarizes the processing methods of Epoxy-graphite based compounds in order to get better-synthetized samples. First, the applying of an epoxy-amine matrix composed of bisphenol A diglycidyl ether (DGEBA) and aliphatic triglycidyl ether epoxy resins cured with a polyether triamine is presented. Next, two different preparations to obtain high quality expanded graphite focuses on an appropriate graphite exfoliation were evaluated. Subsequently, three processes from graphite-resin compounds synthesis are detailed and analyzed based on Energy Dispersive X-ray Spectroscopy (EDS), Scanning Electron Microscopy (SEM), electrical conductivity tests, and particle size characterization. Besides, the effect of using different secondary fillers such as Carbon Black (CB), Graphite nanoplatelets (N99), and graphene (GR) is shown, concluding that the greater electrical conductivity is obtained using graphene in low percentages (0.5%), reaching 65.39 s.cm−1. Finally, a functional method of compression and extraction to avoid damage to the specimen is proposed.

The development of green energy conversion devices has been promising to face climate change and global warming challenges over the last few years. Energy applications require a confident performance prediction, especially in polymer electrolyte fuel cell (PEFC), to guarantee optimal operation. Several researchers have employed optimization algorithms (OAs) to identify operating parameters to improve the PEFC performance. In the current study, several nature-based OAs have been performed to compute the optimal parameters used to describe the polarization curves in a PEFC. Different relative humidity (RH) values, one of the most influential variables on PEFC performance, have been considered. To develop this study, experimental data have been collected from a lab-scale fuel cell test system establishing different RH percentages, from 18 to 100%. OAs like neural network algorithm (NNA), improved grey-wolf optimizer (I-GWO), ant lion optimizer (ALO), bird swarm algorithm (BSA), and multi-verse optimization (MVO) were evaluated and compared using statistical parameters as training error and time. Results gave enough information to conclude that NNA had better performance and showed better results over other highlighted OAs. Finally, it was found that sparsity and noise are more present at lower relative humidity values. At low RH, a PEFC operates under critical conditions, affecting the fitting on OAs.

Polymer Electrolyte Fuel Cells (PEFCs) have great potential as clean energy conversion devices. Therefore, studies are required to increase the understanding of a PEFC at real operating conditions. Two variables that significantly affect the performance are the temperature and the current load. In the present study, a fundamental constitutive part’s performance, e.g., the polymeric membrane (PM) Nafion 212, was evaluated by obtaining its proton conductivity. Also, the cell performance is evaluated considering its output power. Tests were performed in a temperature range of 40-90 °C in steps of 5 °C at a constant current of 50 A. The results show a direct correlation between the proton conductivity and the temperature, and for temperatures greater than 85 °C, the proton conductivity has a growth negligible. It was also found that the PEFC output power has an exponential trend with maximum performance at 75 °C with a power of 25.1 W and proton conductivity of 63 mS.cm−1. Besides, an analysis of the internal factors that impact the proton conductivity and the performance is presented. Finally, empirical correlations for proton conductivity and power output as a function of the temperature with an R-squared larger than 0.96 are proposed.

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