Investigation on the variation law of gas liquid solid three phase boundary in porous gas diffusion electrode.

ABSTRACT

The three-phase boundary length will change with the electrochemical reaction in the working process of the gas diffusion electrode. The process of porous media fluid interface movement is investigated by establishing the physical and mathematical model of the microporous electrode. Using a numerical simulation method, the electrode section electron micrographs are topologically gridded to investigate the micro flow phenomenon of the gas diffusion electrode in the zinc-air battery. By simulating the development process of the electrolyte interface in the porous electrode, the law for the variation of the total length of the three-phase boundary is observed. The results show that the total length of the three-phase boundary increases first and then shortens with the change of gas diffusion and electrolyte electrode movement. A similar trend is observed when the peak power is varied. A theoretical expression for that defines the changes in the length of the three-phase boundary is provided. Finally, we show that the topology and the grid method are feasible means that can be used to analyze electrochemical reactions in complex multiphase flows.