Preparation And Electrochemical Properties Of Ti_1.4V_0.6Ni Compositen Materials

Ti1.4V0.6Ni with icosahedral phase has higher specific capacity(>270 m Ah g^-1)as negative electrode material of nickel metal-hydride battery.However,the cycle stability of this material is not very good.In this dissertation,Ti1.4V0.6Ni as main research object is investigated by doping Ti N?MoS2?La Y2Ni9.7Mn0.5Al0.3 with mechanical ball milling method,in order to improve electrochemical hydrogen storage performance.The specific research contents and results are as follows:(1)Preparation,microstructure and electrochemical properties of the Ti1.4V0.6Ni+x Ti N(x=1,2,3,4 wt%)composite materials.The results of Ti1.4V0.6Ni doping with3 wt%Ti N shows excellent cycle stability,higher discharge retention rate and good high-rate discharge performance.Compared with Ti1.4V0.6Ni material,S50 increases by20%.After 50 charge/discharge cycles,Ti N is still well dispersed on the surface of the material,which plays a role in inhibiting the degradation of the material.(2)Ti1.4V0.6Ni+x MoS2(x=5,10,15,20 wt%)composite is prepared as well.The structure and electrochemical properties of the composite are studied.The results show that the composite electrode with MoS2 increases electrochemical reaction rate and decrease charge transfer resistance than the bare one,as a result that MoS2 has high electro-catalytic activity and good conductivity.With adding MoS2,the high-rate discharge performance of Ti1.4V0.6Ni composite electrode is improved due to the ion concentration is adjusted on the surface of Ti1.4V0.6Ni materials.(3)Ti_1.4V_0.6Ni+x La Y₂Ni_9.7Mn_0.5Al_0.3(x=10,20,30 wt%)composite materials are prepared to study the microstructure and electrochemical properties of the materials.The maximum discharge capacity of Ti1.4V0.6Ni+30 wt%La Y2Ni9.7Mn0.5Al0.3composite alloy can reach 300 m Ah g^-1,which is about 15 Q11111%higher than that of the pure Ti1.4V0.6Ni electrode.