表面电镀镍pH值对La-Mg-Ni系贮氢电极的影响

研究了电镀pH值对表面镀镍的La-Mg-Ni系贮氢电极的影响.电镀后,电极表面被电镀的镍层覆盖.随着pH值的升高,电极的耐蚀性能和循环性能先减弱,后增强,比容量先降低,后提高;极化电阻减小,交换电流增加.当pH=4时,电极1C循环40次后的放电比容量为270 mAh/g,容量衰减率为11%.当pH=5时,极化电阻最小、交换电流最大,电极表面的电催化活性最好,合金中的氢扩散系数为9.69×10-10 cm2/s,电极的动力学性能最好.     

Effects of Mn content on microstructure and electrochemical properties of LaNi4.2-xCo0.6MnxAl0.2 （x=0-0.2） hydrogen storage alloys

The effects of Mn content on microstructure and electrochemical properties of LaNi4.2-xC%6MnxAl0.2 alloys were investigated systematically. The results of XRD analyses indicate that the substitution of Mn does not change the crystal structure, but along with the increase of Mn substitution quantity, the volume of the crystal increases and the ratio of axial to radial lattice parameters （a/c） first increases, then decreases. With the increase of Mn substitution quantity in LaNi4.2-xCo0.6Mnx Al0.2, the discharge capacity, charge efficiency, the self-discharge and high rate discharge capacity increase first and then decrease. The discharge capacity reaches the highest value of 367 mA.h/g （x=0.1） at 0.2C.     

锂离子电池正极材料LiFePO_4的研究进展

磷酸铁锂(LiFePO4)材料具有无毒性、成本低、热稳定性高、充放电平台平稳等优点,被认为是最有前景的锂离子电池正极材料。本文介绍了LiFePO4材料常用的制备方法及其改性方案,对磷酸铁锂今后的发展方向进行了展望。