Effect Of Oxide Mingle With Electrochemical Properties On Mg₂Ni Hydrogen Storage Electrode Alloy

The Mg2Ni hydrogen storage alloy have attracted much attention with discharge capacity was up to 999mAh/g. However, due to alloy electrode was corrosive easily in alkaline electrolyte, leading to low electrode discharge capacity and cycle stability; besides adverse factors of its high costs and exact demands in preparation, storage and transportation, which hindered the large-scale applications of Mg2Ni hydrogen storage alloy. In order to improve electrochemical properties and reduce the cost of commercial application, the oxide (La2O3, CaO, Fe2O3) additive on Mg2Ni hydrogen storage alloy was attempted in this thesis, and some value results are given.Firstly, in order to explore the condition that have not protect gas such as argon in ball-milling pot and directly in the air, and to reduce the research cost.The effect of doping elements mingle with hydrogen storage alloy of electrochemical properties. In the same conditions, the metal powder(Al, Ni, Ti) and metal oxide(La203, CaO, Fe2O3) mingle with Mg2Ni hydrogen storage alloy. The researches show that the discharge capacity was sharp fall with metal simple substances and the maximum discharge capacity is creased with metal oxide.Secondly, the effect of ball-milling time and charge current and discharge current on the 5wt%La2O3-5wt%CaO-Mg2Ni hydrogen storage alloy. The researches show that the discharge capacity was fall and the capacity retention was increased with the ball-milling time was increased. And the alloy electrode with charge current of 100mA/g and discharge current of 60mA/g exhibits the best electrochemical properties.Finally, the effect of ball-milling time and the proportion of doping content on the La2O3-Fe2O3-Mg2Ni hydrogen storage alloy. The researches show that the same result that the discharge capacity decreased with ball-milling time increased. When alloy component ratio is 0.5:0.5:9, the initial maximum discharge capacity was only slightly lower, and after 6-8 cycles, alloy discharge capacity more than other doping ratio, and the capacity retention rate is the highest, the electrode potential is the widest platform, the electrochemical properties of the alloy was the best.