关键词: 储氢合金, 表面包覆, 铜, 循环伏安, 电位阶跃

Abstract: Negative electrode made from Cu microencapsulated hydrogen storage alloy was studied by using cyclic voltammetry method. The results showed that copper as a coating material was of a certain stability in 5 mol/L KOH solution within the range of charge and discharge voltage. But when expanding the sweep voltage, the CV curve showed a pair of distinct oxidation reduction current peaks of Cu 2O formation at E =-0.3 V and Cu 2O reduction at E =-0.6 V. With charging discharging cycles, copper is liable to be oxidized to Cu 2O and further oxidized into CuO 2- 2. When charged again, CuO 2- 2 anion is reduced and Cu is electrodeposited on the sufrace of electroce. In respond to this phenomenon, the electrodeposition process of CuO 2- 2 on the smooth Ni electrode was studied by constant potential step technique. The results showed that the deposition process of copper followed the two dimension instantaneous mechanism.

Key words: Hydrogen storage alloy, Microencapsulation, Copper, Cyclic voltammetry, Constant potential step technique, Electrodeposition