非晶态MgNi+x%B储氢合金的制备及其电化学性能

Preparation and Electrochemical Characteristics of Amorphous MgNi+x%B Hydrogen Storage Alloys

采用机械合金化方法制备了非晶态MgNi+x%B(x=0,2,5,10)储氢合金材料。XRD结构分析表明,含B三元合金的非晶衍射峰的半高宽较宽。合金电极的放电容量随B含量的增加先增加后减小,MgNi+5%B合金电极的放电容量较MgNi合金电极提高了11.9%。合金电极的循环稳定性随B含量的增加而增加,MgNi+10%B合金电极的容量保持率S10较MgNi合金电极提高了67.76%。添加B改善了合金电极的动力学性能,MgNi+5%B合金电极的HRD400、I0和IL分别较MgNi合金电极提高了40.0%,351.5%和20.21%。

Amorphous MgNi＋x%B （x = 0,2,5,10） hydrogen storage alloys are prepared by mechanical alloying （MA） method. The structure of these alloys is examined by X-ray diffraction. Results show that the full width at half maximum （FWHM） of diffraction peaks of ternary alloys is increased. The discharge capacity of the alloy electrodes is firstly increased, and then is decreased with increasing the addition of B. Compared with MgNi alloy electrode, the discharge capacity of MgNi＋5%B alloy electrode is increased by 11.9 %. The electrochemical cycle stability of the alloy electrodes is increased with increasing boron additions compared with no boron additions, the cycle capacity retention rate S10 of the alloy with 10%B is increased by 67.76%. The kinetic properties of the alloy electrodes are improved by adding the boron. Compared with MgNi alloy electrode, the HRD400, 10 and ILof MgNi＋5%B alloy electrodes are increased by 40. 0%, 351.5% and 20.21%, respectively.