Performance of nickel electrode for alkaline water electrolysis prepared by high pressure cold spray

• Published in: International journal of hydrogen energy 2020-11, Vol.45 (58), p.33007-33015
• Main Authors: Jiang, X.G., Zhang, Y.P., Song, C., Xie, Y.C., Liu, T.K., Deng, C.M., Zhang, N.N.
• Format: Article
• Language: English
• Subjects: Alkaline water electrolysis; HER; High pressure cold spray; Ni electrode; Tafel slope
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2020.09.022

To promote Ni electrode performance during water splitting, a novel coating process, High pressure cold spray, is applied to prepare electrodes from blended Ni + Al powder. By controlling Al fraction, electrodes are obtained with varied microstructure. SEM and EDX are implemented to check the micromorphology of electrodes. Linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) are performed to estimate the effect of Al addition on electrode performance. Resultantly, significant improvement of electrode performance is achieved by increasing the fraction of Al from 10 vol% to 20 vol%. The obtained coatings are found with numerous pores owing to the removal of Al during the activation. By applying electrochemical test, the HER of all samples are dominated by Volmer step, and sample N20A is found with the highest active surface area. Thus, sample N20A exhibits the highest electro-catalytic activity to HER of alkaline water electrolysis. [Display omitted] •Two types of porous electrodes are obtained with controlled porosity.•With 20 vol% Al addition the obtained electrode exhibits highly porous structure.•The highly porous electrode presents lower impedance and smaller capacitive phase.•The highly porous electrode is more active for HER of alkaline water splitting.