Acta Phys. -Chim. Sin. ›› 1998, Vol. 14 ›› Issue (08): 742-746.doi: 10.3866/PKU.WHXB19980814

• ARTICLE • Previous Articles     Next Articles

Surface Treatments of Hydrogen Storage Alloy lmprove Charge-discharge Performances of Ni/MH Battery

Chen Wei-Xiang, Chen Yun, Pan Hong-Ge, Chen Chang-Pin   

  1. Department of Materials Science and Engineering,Zhejiang University,Hangzhou 310027
  • Received:1997-11-18 Revised:1998-04-07 Published:1998-08-15
  • Contact: Chen Wen-Xiang

Abstract:

The hydrogen storage alloys were treated by two kinds of surface cl1emical treatments to improve the activation property of MH electrodes and 1C charge/discharge characteristics of Ni/MH batteries. The first was the alloys were immersed in 6 mol•L-1 KOH solution at 80℃ for 8h, the second was the alloys were immersed in 6 mol•L-1 KOH solution containing 0.04 mol•L-1 KBH4 at 80 ℃ for 8h. The effects of chemical treatments on performances of MH electrodes were evaluated by discharge capacity, polarization and electrochemical impedance. Electron probe analyses for the surface composition of the alloy indicated that a Ni-rich surface layer with high electrochemical activity was formed on the alloy surface by preferential dissolution of Al.Ni/MH batteries employing treated alloys as negative electrode material have long cyclic life at 1Cand higher capacity over 1.2V.

Key words: Hydrogen storage alloy, Ni/MH battery, Surface chemical treatment, Cyclic life