Lifetime Prediction of a Polymer Electrolyte Membrane Fuel Cell under Automotive Load Cycling Using a Physically-Based Catalyst Degradation Model

Manik Mayur,Pascal Schott,Wolfgang Bessler,Mathias Gerard

doi:10.3390/en11082054

Abstract

One of the bottlenecks hindering the usage of polymer electrolyte membrane fuel cell technology in automotive applications is the highly load-sensitive degradation of the cell components. The cell failure cases reported in the literature show localized cell component degradation, mainly caused by flow-field dependent non-uniform distribution of reactants. The existing methodologies for diagnostics of localized cell failure are either invasive or require sophisticated and expensive apparatus. In this study, with the help of a multiscale simulation framework, a single polymer electrolyte membrane fuel cell (PEMFC) model is exposed to a standardized drive cycle provided by a system model of a fuel cell car. A 2D multiphysics model of the PEMFC is used to investigate catalyst degradation due to spatio-temporal variations in the fuel cell state variables under the highly transient load cycles. A three-step (extraction, oxidation, and dissolution) model of platinum loss in the cathode catalyst layer is used to investigate the cell performance degradation due to the consequent reduction in the electro-chemical active surface area (ECSA). By using a time-upscaling methodology, we present a comparative prediction of cell end-of-life (EOL) under different driving behavior of New European Driving Cycle (NEDC) and Worldwide Harmonized Light Vehicles Test Cycle (WLTC).

Highlights

Fuel cell durability is currently the biggest bottleneck in the commercialization of fuel cell electric vehicles
This paper focuses on the role of different automobile induced load cycles on Pt dissolution and its effect on durability of a polymer electrolyte membrane fuel cell (PEMFC)
Pt dissolution cathode a Pt particle radius nm andFigure keeping air humidity in cathode, Figure 5awith shows that the c at and forincreases a Pt particle of radius

Summary

Introduction

Fuel cell durability is currently the biggest bottleneck in the commercialization of fuel cell electric vehicles. In a highly transient loading environment such as an automobile, a fuel cell does undergo potential cycling and cycling of various internal state variables such as temperature, pressure and humidity. Such a cyclic operation leads to multiple degrading side reactions, eventually rendering the fuel cell unable to provide the requested power demand or fail catastrophically. The commonly used platinum (Pt)-based catalysts are state of the art due to their low overpotentials and high catalytic activities for hydrogen oxidation reaction (HOR) and oxidation reduction reactions (ORR) [1,2], but the downside is that they are expensive and prone to high rates of degradation. In order to predict fuel cell durability or propose effective mitigation strategies, one needs to focus on degradation mechanisms leading to Pt loss, including the search for lifetime-extending operating strategies

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