The Study On RuO₂·xH₂O Promotes The Dynamic Response Of PEMFC

The proton exchange membrane fuel cell (PEMFC) possesses several highly advantageous features such as low operating temperature, quick startup, high energy density, and no pollution, which make PEMFC as the most promising and attractive candidate for electric vehicle power. However, the process of energy output of PEMFC is composed of electrochemical reaction, gas transfer, proton transfer and electron transmitting, which happens one after another. Instantaneous current makes the output voltage of fuel cell drop to zero even negative, which will effect the nature life of fuel cell seriously. The development of power assistance for PEM fuel cell is, therefore, of great interest.RuO₂·xH₂O is supercapacitor material, which owns higher power capacity and easier preparation technology. RuO₂·xH₂O is added into MEA by two methods: one is that RuO₂·xH₂O as a layer between the membrane and the catalyst layer and another is that Nafion membrane is soaked by RuO₂·xH₂O, which is done in this paper as a new method to resolve the dynamic response problem of PEMFC.Take the activeness of Pt to determine as the RuO₂·xH₂O level most amounts. According to charge-discharge experiment it ensures that the optimization of highest capacity.When Pt:Ru is 1:1, RuO₂·xH₂O doesn't destroy the activeness of Pt by cyclic voltammetry and single fuel cell performance. The dynamic response of voltage in different current and multi-potential steps chronoamperomertry result demonstrate that RuO₂·xH₂O as capacitive material cushions the voltage of fuel cell at current pulse loadings.The prepared membrane with RuO₂·xH₂O has carried on surface observation and the power spectrum analysis. It confirms that RuO₂·xH₂O exists and the disperser is even. The CV of the MEA with RuO₂·xH₂O shows that RuO₂·xH₂O doesn't destroy the activeness of Pt. The EIS of MEA shows that the resistance of the MEA decreases 0.1Ω. And the durability test shows that RuO₂·xH₂O improves the dynamic durability of the MEA.Also, fuel cell current loading in step by step mode show that RuO₂·xH₂O can buffer current instantaneous loading and decrease the gas starvation phenomena due to gas response rate lagging the loading rate in order to protect the fuel cell. Meanwhile, it shows that RuO₂·xH₂O could keep the voltage of PEMFC steady, when the loading current waves in a small range.