球磨表面包覆对镁基贮氢合金电化学性能的影响

Effect of surface coating by ball milling on cycle stability of Mg-based hydrogen storage electrodes

表面包覆是一种表面改性方法 ,对于提高贮氢合金表面活性 ,防止氧化和抑制容量衰退都有较积极的作用。探索了以球磨方法对二元非晶合金Mg5 0Ni5 0和三元非晶合金Mg( 5 0 -x)TixNi5 0 (x =5 ,10 ,15 )进行表面包覆的工艺及其对合金电极充放电循环稳定性的影响。结果表明 :Y ,Al,Ni等包覆元素皆可在一定程度上延缓非晶合金Mg5 0Ni5 0较快的循环容量衰退 ,而且Ni对Mg( 5 0 -x)TixNi5 0 (x =5 ,10 ,15 )

Surface coating is a kind of surface modification, which plays positive roles in improving the surface activation of hydrogen storage alloys, protecting alloys from oxidation and depressing the capacity degradation. The technology of coating on binary Mg50Ni50 and ternary Mg(50- x )Ti x Ni50( x =5, 10, 15), and its effect on alloys cycle stability were also reported. The research indicated that the coating of elemental Y, Al and Ni all retard the rapid capacity degradation of amorphous Mg50Ni50 to some degree, and the coating with Ni can effectively improve the cycle stability of Mg(50- x )Ti x Ni50( x = 5, 10, 15) electrodes. The mechanical alloying (MA) technology and the phase structure transformation during the process of MA were discussed.