【摘要】 采用电子探针(EPMA)、X射线衍射(XRD)和电化学测试研究了在6mol/LKOH电解液中添加Cu(OH)2对La2MgNi7.5Co1.5贮氢合金电极电化学性能的影响。结果表明,合金电极外表面上被镀上Cu膜,Cu膜的厚度和致密性随充放电循环次数的增加而增加,合金电极表面形成致密性Cu膜,可以有效地抑制电极内部贮氢合金的氧化,但对贮氢合金颗粒粉化的抑制作用不明显。在电解液中添加Cu(OH)2,增加了La2MgNi7.5Co1.5合金电极的活化次数,降低了该合金电极的高倍率放电性能,但对合金电极的最大电化学放电容量没有负面影响。此外,利用电沉积方法在电极表面镀Cu膜能够明显改善该合金电极的电化学循环稳定性。更多还原

【Abstract】 The influence of addition of Cu(OH)2 to 6 mol/L KOH alkaline electrolyte on electrochemical properties of La2MgNi7.5Co1.5 hydrogen storage alloy electrode was investigated by means of X-ray diffraction (XRD), electron probe X-Ray microanalysis (EPMA) and electrochemical measurements. EPMA micrographs and XRD patterns show, when the surface of the alloy electrode is plated by metal copper film, the thickness and compactness of Cu film increase with the increment of charge-discharge cycle number. The copper film of the alloy electrode surface can inhibit alloy particle oxidation in the electrode interior, but can not improve the anti-pulverization of the alloy. Addition of Cu(OH)2 to alkaline electrolyte lowers the activation property and high rate dischargeability of the La2MgNi7.5Co1.5 alloy electrode, but has no negative effect on the maximum discharge capacity. Moreover, it is very effective to improve the cyclic stability of the alloy electrode using electrodeposit Cu film on the alloy electrodes surface.更多还原