干荷电式锌空气电池锌电极添加剂的研究

Study on additives for porous zinc electrode of the dry-charged zinc-air cell

为了提高金属锌电极在干荷电式锌电池中的利用率和改善电池的电性能,采用辊压法制备了以乙炔黑和羧甲基纤维素钠(CMC)混合物为添加剂的多孔锌电极。通过恒流放电测试、阳极极化曲线测试、交流阻抗测试和扫描电镜分析等方法对锌电极的电性能进行了分析研究。结果表明,添加了乙炔黑和羧甲基纤维素钠混合物的多孔锌电极在75mA/g的放电电流密度下,其放电比容量从原来的362mAh/g提高到了566mAh/g;加入这些添加剂,降低了电极的电荷迁移阻抗,而且使得锌电极表面的钝化产物变得细小,保持了电极多孔性质,延迟了锌的钝化。

Conductive agent acetylene black and water-absorbent sodium carboxymethyl cellulose were added to zinc electrode of dry-charged zinc-air cell to increase capacity utilization of zinc electrode and improve the cell performance, The effects of the additives were also studied by discharge test, anode polarization, AC impedance and SEM. The results show that the discharge capacity of zinc electrode increases from 362 mAh/g to 566 mAh/g at moderate discharge rate of 75 mA/g. The AC impedance measurement indicates that the additives decrease the charge transfer resistance. And the SEM shows the additives make the discharged production on the zinc electrode much smaller and keeps crude porous structure intact. The passivation of zinc has been postponed.