The H₂/air-fed proton exchange membrane fuel cell (PEMFC) has two major problems: cost and durability, which obstruct its pathway to commercialization. Cell reversal, which would create irreversible damage to the fuel cell and shorten its lifespan, is caused by reactant starvation, load change, low catalyst performance, and so on. This paper will summarize the causes, consequences, and mitigation strategies of cell reversal of PEMFC in detail. A description of potential change in the anode and cathode and the differences between local starvation and overall starvation are reviewed, which gives a framework for comprehending the origins of cell reversal. According to the root factor of cell starvation, i.e., fuel cells do not satisfy the requirements of electrons and protons of normal anode and cathode chemical reactions, we will introduce specific methods to mitigate or prevent fuel cell damage caused by cell reversal in the view of system management strategies and component material modifications. Based on a comprehensive understanding of cell reversal, it is beneficial to operate a fuel cell stack and extend its lifetime.

This dataset collects the long-term dynamic durability test data and the polarization characterization test data used in our research article [1]. The dynamic durability test and the polarization characterization test of a single proton exchange membrane fuel cell (PEMFC) are all performed on the Greenlight 20 test station. The European harmonized test protocol is adapted to construct the fuel cell dynamic load test cycle (FC-DLC) used in this work. The overall durability test is composed of 3076 FC-DLC cycles, around 1008 h. To access the degradation information of the test fuel cell, the polarization characterization tests are performed periodically during the durability test. In this work, the characterizations were performed at time: 0, 100, 200, 300, 400, 500, 600, 700, 800, 900, and 1000 h. During the test period, G20 test station records all measured data, includes the dynamic load durability test dataset and the polarization test dataset. The output voltage degradation trend as well as the polarization curves are plotted and described in this work. This dataset provides the possibilities to study the degradation phenomenon of fuel cell operating by dynamic load cycles, moreover, this dataset can be directly used to various prediction models build for fuel cells.

In this paper, the composition, function and structure of the catalyst layer (CL) of a proton exchange membrane fuel cell (PEMFC) are summarized. The hydrogen reduction reaction (HOR) and oxygen reduction reaction (ORR) processes and their mechanisms and the main interfaces of CL (PEM|CL and CL|MPL) are described briefly. The process of mass transfer (hydrogen, oxygen and water), proton and electron transfer in MEA are described in detail, including their influencing factors. The failure mechanism of CL (Pt particles, CL crack, CL flooding, etc.) and the degradation mechanism of the main components in CL are studied. On the basis of the existing problems, a structure optimization strategy for a high-performance CL is proposed. The commonly used preparation processes of CL are introduced. Based on the classical drying theory, the drying process of a wet CL is explained. Finally, the research direction and future challenges of CL are pointed out, hoping to provide a new perspective for the design and selection of CL materials and preparation equipment.