Effect of low voltage limit on degradation mechanism during high‐frequency dynamic load in proton exchange membrane water electrolysis

Abstract

With regard to the hydrogen economy, setting the criteria for the durability evaluation of renewable energy-powered proton exchange membrane water electrolysis (PEMWE) systems is an important milestone. In this study, accelerated stress test (AST) protocols that simulate the fluctuating power supply of renewable energy were explored. The average load was varied by changing the low voltage limit (LVL = 1.4, 1.5, 1.7, and 1.9 V) with fixation of a high voltage limit of 2.2 V. AST protocols can accurately reflect the real solar profile with various loads and high ramp rates. Protocols with the LVL = 1.4 V and LVL = 1.5 V demonstrated opposite trends even with minimal difference in LVL, resulting in positive and negative degradation slopes, respectively. The positive degradation slope (meaning performance decrease) for LVL 1.4 V is attributed to the reversal current, resulting in degradation of the cathode catalyst, which is characteristic of the fuel cell operating mode. On the contrary, a slight performance increase was observed for LVL 1.5 V, presumably caused by the thinning of the membrane and the creation of a rougher surface in the anode/membrane interface. Meanwhile, protocols with higher LVL (LVL 1.7 V and LVL 1.9 V) showed significant mass transport loss observed at voltages larger than 1.8 V. This may be attributed to severe delamination of the catalyst/membrane and/or diffuse layer/catalyst interface, presumably due to the changes in bubble nucleation and the resulting stress. The findings suggest a rational guideline for establishing a unified AST protocol applicable to renewable energy-powered PEMWE systems, and subsequent material development strategies to minimize degradation processes.

Design and experimental set-up of hydrogen based microgrid: characterization of components and control system development

“…Once the communication with electrolyzer is successful, the station monitors in real time the following parameters: pressure, hydrogen flow rate production and its temperature, the power absorbed by the electrolytic cell, the temperature and conductivity of the water. In particular, the data regarding the cell voltage can be useful to study the degradation phenomena of the cell over time [10].…”

Standardizing OER Electrocatalyst Benchmarking in Aqueous Electrolytes: Comprehensive Guidelines for Accelerated Stress Tests and Backing Electrodes

“…However, the AST protocol remains an important parameter that requires a thorough evaluation as it can significantly impact the obtained stability metrics. Prior studies have examined the impact of the upper potential limit (UPL) of ASTs in half-cell tests and the effect of the lower voltage limit in membrane electrode assemblies (MEAs) . Both studies have highlighted the potential impact of these parameters on the degradation of the Ir performance.…”

“…Prior studies have examined the impact of the upper potential limit (UPL) of ASTs in half-cell tests 22 and the effect of the lower voltage limit in membrane electrode assemblies (MEAs). 23 Both studies have highlighted the potential impact of these parameters on the degradation of the Ir performance. However, additional research is required to gain a more comprehensive understanding of their effects.…”

Combination effect of flow channel configuration and anode GDL porosity on mass transfer and performance of PEM water electrolyzers

“…[1][2][3] Among various alternatives to produce hydrogen, the proton exchange membrane (PEM) electrolyzer has attracted lots of attention due to its high current density (1$5 A cm À2 ), high purity hydrogen production (99.999%), fast response, and safety due to non-corrosive electrolyte. 4,5 Despite these advantages, the large-scale application of the PEM electrolyzer at present is limited by the price and particularly durability. By applying appropriate methods to optimize the mass transfer of the electrolyzer, the performance can be improved, which helps to reduce the cost and improve the life time.…”