论文部分内容阅读
在Ar气保护下用悬浮熔炼制备La0.7Pr0.15Nd0.05Mg0.3N i3.3-xCo0.2A l0.1(Co0.75Mn0.25)x(x=0.0,0.2,0.4,0.6)合金,系统研究了Co和Mn对合金储氢性能和电化学性能的影响。XRD相分析表明,合金相主要由(La,Pr)(N i,Co)5,LaMg2N i9,(La,Nd)2N i7和LaN i3相组成;添加Co和Mn后合金中(La,Pr)(N i,Co)5,(La,Nd)2N i7和LaN i3相晶胞体积增加,LaMg2N i9相晶胞体积变小。合金放氢PCT曲线测试表明,随着合金中Co和Mn含量的增加,合金吸氢量先减小后增加,放氢平台压下降,合金氢化物稳定性增加。合金电极电化学性能测试表明,添加Co和Mn使合金电极放电容量减小,容量保持率S100从53.2%(x=0.0)增加到63.0%(x=0.6),合金电极的电循环稳定性增强,高倍率放电性能HRD1500先增加后减小。此外,合金电极的极化电阻先减小后增加,交换电流密度、循环伏安特性阳极峰电流密度和极限电流密度先增加后减小,合金内氢原子扩散系数先增加后减小,表明添加适量的Co和Mn可以提高合金电极的电化学动力学性能。
La0.7Pr0.15Nd0.05Mg0.3N i3.3-xCo0.2A l0.1 (Co0.75Mn0.25) x (x = 0.0,0.2,0.4,0.6) alloy was prepared by suspension melting under Ar gas protection. The system The effects of Co and Mn on the hydrogen storage and electrochemical properties of the alloys were investigated. XRD analysis showed that the alloy phase mainly consisted of (La, Pr) (Ni, Co) 5, LaMg2Ni9, (La, Nd) 2Ni7 and LaNi3. (Ni, Co) 5, (La, Nd) 2Ni7 and LaNi3 phase cells increased, and the volume of LaMg2Ni9 phase cells became smaller. The PCT curve of the hydrogen release from the alloy shows that with the increase of Co and Mn content in the alloy, the amount of hydrogen absorption in the alloy first decreases and then increases, and the platen pressure drops and the stability of the alloy hydride increases. The electrochemical performance of the alloy electrode showed that the discharge capacity of the alloy electrode decreased with the addition of Co and Mn, and the capacity retention S100 increased from 53.2% (x = 0.0) to 63.0% (x = 0.6). The electrocatalytic stability of the alloy electrode was enhanced , High-rate discharge performance HRD1500 first increase and then decrease. In addition, the polarization resistance of the alloy electrode first decreases and then increases. The exchange current density and the cyclic voltammetry anodic peak current density and limiting current density first increase and then decrease, and the diffusion coefficient of hydrogen atoms in the alloy first increases and then decreases, indicating that the addition The proper amount of Co and Mn can improve the electrochemical kinetics of the alloy electrode.