Performance of stainless steel 316L electrodes with modified surface to be use in alkaline water electrolyzers

•The mechanized straight-parallel electrodes increased the active area for about 50%•Current density increased, approximately 50% with the same applied voltage differences.•The heat released by the system with lower efficiency was higher (original electrodes)•The chemical pickling treatment did not present a benefit in the mechanized electrodes•The distance that presented the best performance was 6.1 mm.

In this experimental work the performance analysis of four different kinds of stainless steel 316L electrodes to be used in alkaline water electrolyzers for hydrogen production was carried out. The proposed electrodes were: electrodes in their original condition, electrodes with chemical pickling treatment, mechanized electrodes with straight-parallel topology and mechanized electrodes with straight-parallel topology and chemical pickling treatment. The study was repeated for two different spaces between electrodes: 5.3 and 6.1 mm. All the electrodes presented a better performance in the longer distance because in the shorter one the effect of bubble resistance was more notorious. The mechanized electrodes with straight-parallel topology presented the best performance for an increase in the active area of the electrode by approximately 50%, which allowed to increase the current density by an average of 50%. For an equal amount of hydrogen produced between the best and the worst system, the heat released was higher by the system with lower efficiency.