MgNi-x%TiNi_(0.5)Mn_(0.5)(x=10,30,50)贮氢合金的制备与电化学性能  

Preparation and Electrochemical Properties of MgNi-x% TiNi_(0.5)Mn_(0.5) (x=10, 30, 50) Composite Alloys for Hydrogen Storage

作　　者：刘素琴[1] 陈东洋[1] 黄可龙[1] 仲晓玲[1] 

机构地区：[1]中南大学化学化工学院,长沙410083

出　　处：《化学学报》2009年第6期513-518,共6页Acta Chimica Sinica

摘　　要：用机械合金化法成功制备出MgNi和TiNi0.5Mn0.5合金,并将不同质量的TiNi0.5Mn0.5与MgNi合金球磨复合10 h制备MgNi-x%TiNi0.5Mn0.5(x=10,30,50)合金.XRD结果表明球磨后几种合金均为非晶体,TiNi0.5Mn0.5均匀分散到MgNi合金主相中;充放电结果表明MgNi-TiNi0.5Mn0.5复合合金的初始容量比纯MgNi合金(443.12 mAh/g)低,MgNi-10%TiNi0.5Mn0.5首次放电容量是394.46 mAh/g,但循环寿命有较大的改善,50次循环后容量保持在232.57 mAh/g,保持率达59%;动电位扫描结果表明复合后合金电极抗腐蚀能力提高;循环伏安法和电化学阻抗谱法研究结果表明:复合后电极表面的电化学催化性能增强,H原子在合金电极内部的扩散阻抗减小.t MgNi alloy and TiNi0.5Mn0.5 alloy were successfully synthesized by a mechanical alloying （MA） approach. The MgNi and TiNi0.5Mn0.5 alloys were mixed to prepare the MgNi-x% TiNi0.5Mn0.5 （x= 10, 30, 50） alloys by MA for 10 h. The XRD results suggested that the alloys have amorphous structures, and TiNi0.5Mn0.5 alloys have been dissolved in the main phase of the MgNi alloys. The discharge capacity and cycle life of the alloys were tested, showing that the cycle life of the alloys being doped became much better than that of the MgNi alloys. Especially, the discharge capacity ofMgNi-10% TiNi0.5Mn0.5 composition was 394.46 mAh/g, which was lower than that of the MgNi alloy （443.12 mAh/g）, and the discharge capacity was 232.57 mAh/g after 50 cycles with the capacity retention of 59%, potentiodynamic polarization curves showed that anti-corrosion performance of the electrodes became better; cyclic voltammetry （CV） and electrochemical impedance spectroscopy （EIS） tests showed that the electrode catalytic activity was improved significantly and the H atom diffusion impedance decreased after TiNi0.5Mn0.5 doping.

关 键 词：镁基贮氢合金 电化学性能 机械合金化 循环稳定性 

分 类 号：TG139.7[一般工业技术—材料科学与工程]