PEM Fuel Cell Materials: Costs, Performance and Durability

Abstract

Glossary Bipolar plate Forms the connection between MEAs in a fuel cell stack. The bipolar plate includes the gas flow channels and may also include cooling channels. Bipolar plates are also called flow plates. Degradation The gradual loss of performance. Irreversible degradation is due to change of materials properties. Reversible degradation can be caused by non-optimal operating conditions. Quantitatively, the degradation can be expressed as a voltage decay rate. Durability The capability of the fuel cell to operate in the operating window with limited loss of performance. Lifetime The number of hours that a fuel cell can be operated in the operating window with a pre-defined performance loss relative to the initial performance. MEA Membrane electrode assembly is the result of joining two electrodes and the electrolytic membrane together. Usually, the gas diffusion media are considered to be part of the MEA. Operating window The range of conditions in which the PEMFC can be stably operated. Within this operating window, performance can still depend on the conditions, but irreversible performance loss is limited. The operating window includes the modes of operation, such as start/stop events and load cycling. PEMFC Proton exchange membrane fuel cell. The operating temperature is around 80 C. Cold start, below 0 C, is possible. For transport applications, the PEMFC is the fuel cell of choice.