Accelerating operating conditions for electrode degradation

Kurzfassung

Today, lifetime of fuel cells is a limiting factor for commercialization in most application fields. Depending on the different application fields the operating conditions strongly differ and consequently also the durability of fuel cells is changed significantly. For instance, in the residential application average life-times of about 8000 h have already been reported whereas the automobile applications with high dynamic operation reduces the life-time to about 1000 h in the recently demonstrated fuel car fleets. The degradation processes and rates – especially in the active electrochemical components, for example, the electrodes – depend strongly on the operating conditions. Vice versa, also the degradation effects change the local operating conditions and therefore the interactions are complex. In this presentation, the influence of water management, specifically of the liquid phase in the cell, and the degradation processes of electrodes will be reported which has been extensively studied. At high liquid water contents in the electrode the agglomeration of the catalyst, the decrease of the hydrophobicity, and carbon corrosion can be accelerated. In addition, other accelerating operating conditions known from literature and sometimes still speculative will be discussed.