The influence of replacing Al with B on phase structures and electrochemical properties of AB5 type hydrogen storage alloys was studied. The result shows: CeCo4B -the second phase of hydrogen storage alloys is found after mixing with B, which reduces the electrochemical capacity of hydrogen storage alloys; With the increase of B, diffusion coefficients of hydrogen and exchange current density go up remarkably, while at the same time the polarization resistance decreases, which leads to the improvement of high-rate capability and low-temperature performance of alloys.
A series of low-Co type hydrogen storage alloys are prepared by vacuum induction melting.Through X-ray diffraction(XRD) and electrochemistry,systematical study and analysis is made of the electrochemical performances(maximum discharge capacity,high-rate capability and recycle stability),the microstructure and kinetic characteristics of hydrogen storage alloys.
研究了用B掺杂替代A1对AB5型稀土贮氢合金相结构和电化学性能的影响.对M1Ni3.55Co0.75Mn0.4Al0.3-xBx(x=0,0.1,0.2,0.3)合金的研究结果表明:掺B后贮氢合金出现了CeCo4B第二相,导致贮氢合金的电化学容量下降;随B含量的增加和A1含量的减少,氢的扩散系数明显上升,合金的极化电阻减小,合金的高倍率放电性能和低温性能得到明显改善.
