Efficient drainage design of cathode catalyst layer for pure oxygen proton exchange membrane fuel cells

Abstract

Abstract To promote the application of pure oxygen proton exchange membrane fuel cell (PEMFC) technology in unmanned underwater devices, it is crucial to effectively address the water management problem of the PEMFC. The membrane electrode assembly (MEA) serves as a key component for electrochemical reactions and mass transfer, and the physicochemical properties of the porous structure of the cathode catalyst layer (CCL) determine the efficient transport of reactants and products inside the electrode. In this paper, the effect of hydrophobic modification of polytetrafluoroethylene (PTFE) nanoparticles in the CCL on cell performance was investigated through comprehensive electrochemical tests and physical characterizations. The performance of the optimally modified MEA was significantly improved by 84.6% compared with that of the conventional MEA, which could be mainly attributed to less residual liquid inside the electrode by the hydrophobic modification of PTFE, further proven by electrochemical impedance spectroscopy (EIS) results. The optimization would significantly mitigate the flooding phenomenon in pure oxygen PEMFC and facilitate the continuity of the redox reaction in a highly efficient way.