Membrane chemical degradation long-term durability

Besides performance, durability is another important concern of fuel cells. To evaluate fuel cell durability, two modes, steady-state (continuous running) and shutdown-restart cycling, are often used. In the steady-state mode, a fuel cell is operated continuously at a fixed current density to measure the voltage decay. Quite different durability data from a few hundred hours to nearly twenty thousand hours have been reported in the literature [2,28,47,55-58]. In principle, the durability is affected by many factors such as the chemical stability and conductivity stability of PEMs and the stability of catalyst layer. Oono and coworkers [56] studied the long-term cell degradation mechanism with a PA-doped PBI membrane (DL is unavailable from the literature). The H2/air fuel cell was continuously tested at 150°C at 0.2 A cm" without external humidification. They found that the fuel cell exhibited extremely... 

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