锌空电池气体扩散电极浸液量对放电性能的影响

锌空电池气体扩散电极在存放和放电过程中,电解液会在毛细力的作用下不断浸入电极。电解液在气体扩散电极中的浸入量与分布情况决定了气体扩散电极中的化学反应活化区,从而影响放电性能。通过实验测量了气体扩散电极开始浸液的4天内浸液量与放电性能的关系,并借助拓扑网络数值模拟电解液浸入多孔介质的过程帮助理解该实验现象。结果表明,随着放电过程的进行,浸液量和分布情况不断变化;气体扩散电极放电性能变化主要分为3个阶段:浸液饱和度为39.4%时放电性能最佳;浸液开始2~24小时进行迅速,浸液饱和度达到81%,放电性能小幅下降;24小时之后浸液增速大幅减缓,放电功率随浸液量增加大幅下降。

On the Influence of Infusion Mass on Discharging Performance of Gas diffusion Electrode in Zinc-Air Battery

During storage and discharging process of zinc-air battery, electrolyte may penetrate into gas diffusion electrode ceaselessly due to capillary force. Chemical reaction activating area, thereby the discharging performance, is determined by infusion mass and distribution of electrolyte penetrated into gas diffusion electrode. Relationship between the infusion mass and discharging performance in 4 days after electrolyte penetration beginning was experimentally studied, and with the support of topology network, the process of electrolyte penetration into porous media was numerically simulated. Results indicate that along with the penetration process, the infusion mass and its distribution keep changing, the discharging performance of gas diffusion electrode can be divided into three stages: when infusion saturation degree reaches 39.4%, electrode presents the best discharging performance; from 2-24 hours after electrolyte penetration beginning, penetration develops quickly, when infusion saturation degree reaches 81%, discharging performance declines slightly; after 24 hours, penetration growth slow down sharply, and the discharge power dropped significantly with the increase of infusion.