小孔气体扩散电极的放电机理探索

借鉴植物叶片高效传输的机理,以包含规则排列的贯通直孔的镍片作为骨架材料,与自制催化剂组成小孔气体扩散电极,在锌空气电池体系下与常规泡沫镍电极的放电性能进行比较,并考察不同孔径的小孔气体扩散电极之间的放电特征。结果表明,小孔气体扩散电极相比泡沫镍电极存在更好的放电性能,降低了电极在大电流密度工作时的极化过电位。当电流密度在低于1 000 mA/cm2工作时,放电性能与孔径大小成线性关系,孔径为50μm时,放电效率最佳。总结了小孔气体电极相对泡沫镍气体扩散电极放电效率明显改善,并随着孔径变化放电性能呈现尺度效应,内部结构稳定,间歇放电性能变化较小。

Discharge mechanism of micro pore gas diffusion electrode

A kind of gas diffusion electrode was reported by making of nickel film as framework material with different pore sizes.Under the same test condition,the micro pore gas diffusion electrode was compared with nickel foam gas diffusion electrode in the discharge experiment in the zinc-air battery.The discharge polarization curves were drew between electrodes of different size.The results show that the micro pore gas diffusion electrode has a better performance than the nickel foam electrode,reducing the polarization potential under lager current density.The discharge performance has a linear relationship with pore size distribution when the working current density is lower than 1 000 mA/cm2 and exhibits best performance at the pore size about 50 μm.In summary,the discharge performance is improved significantly by changing the inner structure of gas diffusion electrode and shows scale effect with the pore size distribution of electrode.And the intermittent discharge shows little change for its good stability.