Selection of thermoplastic polymers for use as bipolar plates in direct methanol fuel cell applications

Abstract

The use of polymers in direct methanol fuel cells (DMFCs) would reduce their density and cost, thereby enhancing their commercialization. This work aims to select the most appropriate materials among seven thermoplastic polymers (ABS, CPE, CPE+, Nylon, PC, PLA and TPU 95A) for use as bipolar plates (BPs) for different applications of DMFCs. For that purpose, four multi-criteria decision-making (MCDM) methods (TOPSIS, COPRAS, SAW and AHP) are applied to resolve the problems of material selection. In addition, long-term experiments with these polymers have been carried out in a simulated environment that reproduces the conditions inside DMFCs in order to collect reliable data on the behaviour of the materials during the selection process. According to the results of the experiments, PLA is not an appropriate material for DMFCs because of its extreme degradation in a short period of time. On the contrary, ABS, CPE+ and PC exhibit promising properties, but identifying the proper material for a concrete application with confidence evidently requires the use of MCDM methods. By applying such methods, it is concluded that ABS is the preferred material for stationary and small portable DMFC applications whereas PC is the most appropriate material for DMFCs on board UAVs. Keywords: Direct methanol fuel cell, Material selection, Multi-criteria decision-making, 3D printing