DataSheet1_High-current density alkaline electrolyzers: The role of Nafion binder content in the catalyst coatings and techno-economic analysis.pdf

We report high-current density operating alkaline (water) electrolyzers (AELs) based on platinum on Vulcan (Pt/C) cathodes and stainless-steel anodes. By optimizing the binder (Nafion ionomer) and Pt mass loading (mPt) content in the catalysts coating at the cathode side, the AEL can operate at the following (current density, voltage, energy efficiency -based on the hydrogen higher heating value-) conditions (1.0 A cm−2, 1.68 V, 87.8%) (2.0 A cm−2, 1.85 V, 79.9%) (7.0 A cm−2, 2.38 V, 62.3%). The optimal amount of binder content (25 wt%) also ensures stable AEL performances, as proved through dedicated intermittent (ON-OFF) accelerated stress tests and continuous operation at 1 A cm−2, for which a nearly zero average voltage increase rate was measured over 335 h. The designed AELs can therefore reach proton-exchange membrane electrolyzer-like performance, without relying on the use of scarce anode catalysts, namely, iridium. Contrary to common opinions, our preliminary techno-economic analysis shows that the Pt/C cathode-enabled high-current density operation of single cell AELs can also reduce substantially the impact of capital expenditures (CAPEX) on the overall cost of the green hydrogen, leading CAPEX to operating expenses (OPEX) cost ratio

本研究报告了基于钯碳（Pt/C）阴极和不锈钢阳极的高电流密度碱性（水）电解槽（AELs）。通过优化阴极侧催化剂涂层中的粘合剂（Nafion离子膜）和钯质量负载（mPt）含量，AEL可在以下条件下运行（电流密度、电压、基于氢气高热值的能量效率 - 1.0 A cm−2, 1.68 V, 87.8%; 2.0 A cm−2, 1.85 V, 79.9%; 7.0 A cm−2, 2.38 V, 62.3%）。最佳的粘合剂含量（25 wt%）同样确保了AEL的稳定性能，这通过专门的间歇式（ON-OFF）加速应力测试以及1 A cm−2连续运行得到证实，其中在335小时内平均电压增加率接近于零。因此，设计的AELs能够达到质子交换膜电解槽类性能，无需依赖于稀有阳极催化剂，即铱。与普遍观点相反，我们的初步技术经济分析显示，Pt/C阴极驱动的单电池AELs的高电流密度运行可显著降低对绿色氢气总体成本的资本支出（CAPEX）影响，从而将CAPEX与运营成本（OPEX）的成本比率降低。