Magnetic field Pre-polarization enhances the efficiency of alkaline water electrolysis for hydrogen production

Water electrolysis can become a promising mean to produce clean hydrogen. Improving the efficiency of water electrolysis is of great significance for accelerating the development of large-scale hydrogen production equipment and low-carbon economy. This paper presents a novel method for enhancing the alkaline water electrolysis (AWE) efficiency by Magnetic Field Pre-polarization (MFPP), which is easily matched to high-power industrial AWE system. Firstly, compactly-assembled structure and energy consumption of industrial AWE electrolyzer are analyzed. Secondly, the MFPP method was proposed to enhance the efficiency of AWE. The structure parameters of MFPP equipment are optimized by simulation and the physical model is designed. Finally, a system-level equipment was developed to evaluate the effect of MFPP on the performance of the alkaline water electrolysis (AWE) system. Repeatability measurement, I-V characteristic analysis and error statistics were carried out under different working conditions. The effectiveness of MFPP method has been proved on industrial electrolyzer (with 22 cells). Compared with the electrolysis voltage of 40 V-42 V@22_cell, the efficiency improvement is more significant when the voltage is in the range of 42–46 V@22_cell. Under the 0.75 T MFPP, the maximum hydrogen production efficiency increased by 9.2 %. The mean absolute deviation (MAD) of test results is less than 1.88 (with a proportion of 0.11 %) and the mean squared error (MSE) is less than 0.49.