保压时间对储氢合金电极电化学性能的影响

Effects of the Pressure-Holding Time on the Electrochemical Properties of Mm0.3Ml0.7Ni3.55Co0.75Mn0.4Al0.3 Metal Hydride Electrodes

摘要:

在不同保压时间下制备Mm0.3Ml0.7Ni3.55Co0.75Mn0.4Al0.3储氢合金电极，研究保压时间对合金电极的活化性能、最大放电容量、放电特性和循环稳定性的影响规律和机制。结果表明，保压时间对合金电极的活化性能基本无影响。合金电极的其它电化学性能随保压时间的增加均呈现出先变好后变坏的变化规律，保压时间为15 min时，合金展示了最佳的综合电化学性能，电化学性能的改善主要归因于合金电极的电荷转移速度加速和内阻减小

Abstract:

The Mm0.3Ml0.7Ni3.55Co0.75Mn0.4Al0.3 metal hydride electrodes were prepared at pressure-holding time of t (t=10, 15, 20 and 25 min). The effects of the pressure-holding time on the activation performance, maximum discharge capacity, discharge potential characteristic and cycle stability of the electrode were investigated. The mechanism of the effect of the pressure-holding time on the electrochemical properties of metal hydride electrodes was also discussed in detail. The results show that the pressure-holding time has no effect on the activation performance of the electrode basically, and the other electrochemical properties of the electrodes are improved firstly and then degenerated with increasing of pressure-holding time. The electrode at pressure-holding time of 15 min exhibits the best electrochemical properties. The improvements of the electrochemical properties are attributed to the increase of the charge-transfer reaction rate on the alloy and the decrease of the internal resistance of the electrodes