Structure and electrochemical properties of La_(1-x)Mg_(x)Ni_(2.8)Co_(0.4)Mn_(0.1)Al_(0.2)(x=0.25,0.30,0.33)hydrogen storage alloys  

作　　者：Si Li Huai-Ying Zhou Zhong-Min Wang Jian-Qiu Deng Qing-Rong Yao 

机构地区：[1]School of Material Science and Engineering,Guilin University of Electronic Technology,Guilin,541004,China

出　　处：《Rare Metals》2020年第12期1464-1468,共5页稀有金属（英文版）

基　　金：the National Natural Science Foundation of China(No.51261003);the Natural Foundation of Guangxi Province(Nos.2012GXNS FGA060002 and 2011GXNSFD018004)。

摘　　要：La_(1-x)Mg_(x)Ni_(2.8)Co_(0.4)Mn_(0.1)Al_(0.2)(x=0.25,0.30,0.33)alloys were prepared by induction melting followed by annealing treatments(1,073 K)for 10 h.The structure and electrochemical properties of La_(1-x)Mg_(x)Ni_(2.8)Co_(0.4)Mn_(0.1)Al_(0.2)(x=0.25,0.30,0.33)hydrogen storage alloys were investigated by X-ray powder diffraction(XRD)and electrochemical measurement methods.XRD results reveal that all the alloys mainly consist of LaNi5 phase and La2 Ni7 phase.The electrochemical experiments demonstrate that the substitution of Mg for La can increase the maximum discharge capacity and improve the high-rate dischargeability of the alloy electrodes.The high-rate dischargeability of alloy electrodes increases from 39.4%to63.1%with x increasing from 0.25 to 0.33 at discharge current density of 1,500 mA·g^(-1).However,the addition of Mg reduces the cycling stability of the electrodes.Furthermore,the results obtained from the electrochemical impedance spectroscopy and linear polarization measurements show that the hydriding kinetics on the hydrogen storage alloys are controlled by charge-transfer step.

关 键 词：Hydrogen storage alloy Electrochemical properties High-rate dischargeability Electrochemical impedance spectroscopy 

分 类 号：TG139.7[一般工业技术—材料科学与工程]