Effect of Chemical Copper Microencapsulation on High Rate Discharge Performance of Hydrogen Storage Alloy Electrode
XU Jian-yi WANG Rui-fen LI Xia WANG Qing-chun ZHANG Guo-fang ZHANG Yin
Rare Earth School, Inner Mongolia University of Science and Technology Rare Earth School, Inner Mongolia University of Science and Technology School of Rare Earth, Inner Mongolia University of Science and Technology School of Rare Earth, Inner Mongolia University of Science and Technology School of Rare Earth, Inner Mongolia University of Science and Technology Material and Metallurgical School, Inner Mongolia University of Science & Technology
Abstract：Taking A2B7-type hydrogen storage alloy La1.5Mg0.5Ni6.5Co0.5 as an investigation object, the kinetic properties of the alloy electrode with copper coating by the different chroma of vitriol and without it were studied. The high rate discharge performance of hydride electrode was analyzed from the point of kinetic view. The results showed that the exchange current density I0 of hydride electrode coated by Cu increased obviously with increasing chroma of vitriol. The limiting current density IL of the alloy electrodes increased from 2166.01 mA/g [C(H2SO4)=0.025 mol/L] to 2681.93 mA/g [C(H2SO4)＝0.1 mol/L]. The diffusion coefficient, Dα, of hydrogen in α-phase of hydride electrode was improved with increasing chroma of vitriol. All of the above indicate that the Cu surface microencapsulation can effectively improve the kinetic performance of hydrogen absorption and releasing process of hydride electrode1. The improvement of high-rate discharge ability can be ascribed to the effects of the charge-transfer on the alloy surface and hydrogen diffusion rate in the bulk of alloy.
2010, Vol. 10 
