Electrolysis Visualization and Performance Evaluation Platform for Commercial-Sized Alkaline Water Electrolyzer

Alkaline water electrolysis (AWE) is promising for large-scale commercial production of green hydrogen, but large overpotential hinders their promotion. In order to reduce energy consumption, structure design of bipolar plate is crucial, which calls for a deep understanding of the flow behavior such as flow distribution and product bubble motion inside of the electrolyzers, thus requiring electrolysis visualization and evaluation. But due to challenge of structure design and proper sealing performance, related system/devices for commercial-sized electrolyzer are rare. In the present work, we construct an electrolytic visualization and performance testing system by using 3D computer aided design. Using precision CNC machining of transparent electrolyzer, the internal flow of different structures can be visualized, and the performance of the electrolyzer can be tested simultaneously. Based on the system, two common structured electrolyzer design are investigated, namely concave and convex bipolar plate (CCBP) and metal mesh support electrolyzer. The results indicate that a better flow uniformity is crucial for lower overpotential and the inferior performance of mesh structured electrolyzer at large current density results from bubble impediment in the mesh structure. The current platform can be applied as a general tool for convenient multi-phase investigation and performance evaluation of different structure design components during water electrolysis at a low cost.