Ti_2Ni储氢合金的充放电特性及腐蚀行为

Charge/Discharge Performances and Corrosion Behaviors of Ti_2Ni Hydrogen Storage Alloy

通过球磨晶态Ti2Ni合金制备非晶态Ti2Ni合金,采用X射线衍射、充放电测试、阳极极化曲线对不同结构的Ti2Ni储氢合金的充放电特性及腐蚀行为进行研究。结果表明:晶态Ti2Ni合金的首次电化学充氢容量可达480mAh/g,但首次放氢量仅为充氢量的一半,合金内形成了大量不可逆氢化物相。随后的充放电循环中几乎没有不可逆相的形成。非晶相能够有效抑制充氢过程中不可逆相的形成,且充放氢使非晶合金间隙发生了弹性变形。此外,非晶结构使合金在碱性电解液中的自腐蚀电位升高、腐蚀电流降低,显著提高了合金的耐蚀能力。

An amorphous Ti2Ni alloy was prepared by ball milling of a crystalline Ti2Ni alloy.XRD,charge and discharge testing,and anodic polarization curve were carried out and investigated to study the charge/discharge performances and the corrosion behaviors of Ti2Ni hydrogen storage alloy with different structures.Results show that the crystalline alloy has a charge capacity of 480 mAh/g at first cycle,while its discharge capacity is only a half of the charge capacity.A large amount of irreversible hydride is formed in the bulk alloy.However,there is no evident formation of the irreversible hydride in the subsequent cycle.The amorphous phase can restrain the formation of the irreversible hydride.And a elastic deformation occurs during the hydrogen absorption/desorption process.Moreover,the amorphous structure makes the alloy corrosion potential increasing and the alloy corrosion current density decreasing,resulting in an significant improvement of corrosion resistance of the alloy.