多孔电极三相界面形态的研究

Research on the Three-phase Boundary Shape of the Porous Electrode

研究了多孔气体电极在电池反应中形成的三相界面的形态及其变化规律。传统的电极多采用部分浸没的使用方式 ,不利于观察。笔者通过改变传统的电极安装方式 ,将电极在纵向的距离加大 ,可以任意调节电极纵向高度 ,有利于观察三相界面的形成形态。通过锌空气电池实验 ,总结了三相界面形态的形成以及随着反应时间的变化规律 ,并对三相界面形态的变化使电极内电解液的电导发生变化进而影响电池内电阻进行了理论分析 。

The shape and variation rule of the three-phase boundary of the porous electrode used in batteries and fuel cells are studied. The traditional porous electrode is always partly immersed into the electrolyte, which is difficult to observe the shape and variation of the three-phase boundary. This work changes the traditional usage mode of the electrode to make the observation of the three-phase boundary be easy. The longitudinal height of the electrode can be enlarged and modulated andomly by this new usage mode. The establishment and the variation rule of the three-phase boundary shape as the reaction goes on are summarized by the experiment of the zinc-air battery. This paper theoretically analyses that the variation of the boundary can cause the variation of the electrical conduction of the electrolyte in the porous electrode and affect the internal resistance. It is also illustrated how the wetting property and pore structure of the porous electrode affect the three-phase boundary shape through the experiment.