表面处理对储氢合金电化学性能的影响研究

The Effect of Surface Treatment on Electrochemical Performance of Hydrogen Storage Alloy

通过电化学方法,研究了储氢合金碱化处理及碱液中加入KBH4对合金电极的电催化活性和高倍率放电性能的影响。结果表明:处理后合金颗粒分布均匀,表面变得粗糙。两种处理方法均增加了合金表面的电催化活性,降低了合金电极的极化电阻,从而提高了高倍率放电能力。尤其在900mA/g放电时,处理前合金电极不能放电,单一碱处理合金电极和加入还原剂碱处理合金电极仍具有较高的高倍率放电能力,分别为69.2%和83.4%。在单一碱溶液中加入还原剂KBH4处理后,合金电极的电化学性能明显高于单一碱处理合金电极。

The effects of alkaline treatment and alkaline solution containing KBH4 on the electrocatalysis activation and high rate dischargeability of hydrogen storage alloy electrode were investigated by electrochemical method. The results show that the surface of treated alloy becomes rough. The two ways all improve the high rate dischargeability because of the increase of exchange current density and the decrease of electrochemical impedance of metal hydride electrodes. Especially at a current rate of 900mA/g, the high rate dischargeability of 0.05mol/L KBH4 ＋6mol/L KOH alkaline treatment alloy electrode still remain a higher value of 83.4% relative to 6mol/L KOH alkaline treatment alloy electrode 69.2%, while the original one can not discharge. 0.05mol/L KBH4 ＋6mol/L KOH alkaline treatment can reduce some oxide film, increase the activation, and improve the performance of high rate dischargeability compared with 6mol/ L KOH alkaline treatment.