老化
质子交换膜燃料电池
汽车工业
材料科学
复合材料
加速老化
降级(电信)
汽车工程
化学工程
核工程
法律工程学
燃料电池
电气工程
医学
航空航天工程
工程类
内科学
作者
Elena Colombo,Andrea Baricci,Andrea Bisello,Laure Guétaz,Andrea Casalegno
标识
DOI:10.1016/j.jpowsour.2022.232246
摘要
A long-term dynamic load cycle is performed on state-of-the-art membrane electrode assemblies, aiming to evaluate the degradation mechanisms of Polymer Electrolyte Membrane Fuel Cell under real-world automotive operations. The load cycle, adapted from the stack protocol defined in H2020 ID-FAST European project, includes load, pressure and temperatures cycling. Events that recover the temporary decay are included, specifically procedures classified in short-stops, cold-soaks, long-stops. Operando voltage and current distribution are measured through a segmented hardware, combined to local in-situ electrochemical characterization. Investigation is supported by scanning and transmission electron microscopy analysis, performed at different locations along-the-flow-field. Reversible degradation weights from few to 20 mV and changes local current distribution, mostly at air-inlet, since the dry-out of ionomer. Cycle efficiency decreases of 3%–9%: the largest irreversible performance losses are observed at air-inlet, while middle-region is the least impacted. Cathode catalyst layer and membrane are the most aged components: platinum active surface area drops in 200–400 h, because of electrochemical Ostwald ripening mechanism, and stabilizes around 62%–67% of initial value. Polymer membranes report ageing compatible with mechanical stress that causes localized thinning, increasing hydrogen crossover. Decay of ionomer in the catalyst layer is discussed, which would consistently explain alterations of mass transport resistance. • MEAs degradation study of 1000 h of realistic load cycle on segmented hardware. • Irreversible and heterogeneous degradation of cathode catalyst layer and membrane. • ECSA drops to 62%–67% of initial value. • Air-inlet performance drop is 20 ÷ 90% higher than average at high current density. • Best performant MEA under ageing shows ∼3% of energy efficiency loss.
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