Accelerated Stress Tests Protocol Development for Industrial PEM Electrolyzer Stacks

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The deployment of NEL’s next-gen PEM water electrolyzer stacks and systems is very much dependent on our ability to evaluate the degradation of individual components and thereby predict 50000 hr. operability of the stack. In addition, Nel Hydrogen is constantly working to unveil degradation mechanisms from our long run (< 100.000 hours) fielded stacks, so that we can make the developing of accelerated stress tests (ASTs) less challenging. Typically, performance losses in PEM electrolyzer stacks are the result of electrode, membrane, and/or PTL degradation during different operation strategies. Here we accelerated the performance losses of electrodes used in PEM water electrolyzer stacks using an in-house developed voltage cycling protocol. Membrane degradation was also accelerated through cation-doped catalyst coated membranes and is assessed through ex-situ monitoring of fluoride emission rates during the stack operation. We also leveraged a fielded Nel Hydrogen legacy PEM stack that ran for over 50000 hr. and other R&D stacks that ran for intermediate life span of 5000 hr. at steady state. A correlation of the degradation mechanism to different cell components observed from that of the AST protocols is then here reported.