Optimal operating parameters for advanced alkaline water electrolysis

Advanced zero-gap alkaline electrolyzers can be operated at a significantly higher current density than traditional electrolyzers. We have investigated how their performance is influenced by diaphragm thickness, temperature and pressure. For this semi-empirical current-voltage model has been developed based on experimental data of 20 Nm3/h electrolyzer. The was extrapolated to thinner thicknesses temperatures showing that nominal 1.8 A cm?2 possible with 0.1 mm 100 °C. However, these operating parameters also lead increased gas crossover, which limits the ability operate low loads. crossover developed, shows mainly driven diffusive transport hydrogen, caused high local supersaturation surface. To enable minimum load 10% pressure should kept below 8 bara.