Precious-Metal-Free Coating for PEM Electrolyzer Bipolar Plates

Bipolar plate is an important and expensive component in PEM electrolyzer stacks. Titanium based bipolar plate is the preferred material for industrial use. But titanium plate has the hydrogen embrittle risk and high interface contact resistance with other components in the stack, especially after long term operation. Precious metal coatings, such as gold and platinum, are used on titanium plates to meet the application requirements. But the precious metal costs are very high. The proposed project plans to demonstrate a novel, low cost, precious metal free coating technology on titanium bipolar plate for PEM electrolyzer bipolar plates. It uses high quality carbon particles and titanium alloy particles as the coating material and uses a reliable bonding structure to hold particles through the operation lifetime (>10 years) of PEM electrolyzer stack for clean hydrogen generation. In Phase I of the project, the particle materials will be selected. The coating process will be tailored to produce the desired coating structure on titanium plate surface. The coated titanium plate performance will be demonstrated by ex-situ and in-situ tests. Their performance will be characterized to meet the targets and the manufacture cost analysis will be conducted to ensure the low cost production in large volume. The success of the project will benefit the cost reduction of PEM electrolyzers to meet DOEĺs clean hydrogen production cost of $1/kg by 2031. The manufacturing process of the proposed technology is well developed in the US, making it possible to rapidly scale up the production to meet the market demands, and create green energy jobs in the US.