Analysis and experimental investigation on passive direct methanol fuel cell current collectors with taper cylindrical openings

Analysis of buoyancy effect on the evaluation of carbon dioxide gas from passive direct methanol fuel cell current collectors’ (CCs’) openings is carried out. Two types of setups are chosen for the analysis, one with taper cylindrical openings and the other with uniform cylindrical openings. The analysis shows that buoyancy is more effective in taper cylindrical openings due to the accommodation of a larger bubble volume compared to that bubble volume in a uniform cylindrical opening. In this experimental study, SS‐316L has been selected as the CC material. During the experiment, it is observed that the CO2 is getting expelled more easily. The best power density (PD) obtained using taper cylindrical openings at a methanol concentration of 3 M is 7.056 mW cm−2, whereas it is 5.219 mW cm−2 in the case of uniform cylindrical openings at the same 3‐M methanol concentration. Hence, the taper cylindrical openings are found to perform better at 3‐M concentration than cylindrical openings by 35.19% at its best PD point and further, the weight of the CCs is also reduced leading to gravitational PD improvement. Analysis of charge density over the tapered surface is also carried out.