用含KBH_4碱液处理改善MINi_(3.7)Co_(0.6)Mn_(0.4)Al_(0.3)贮氢合金电极的动力学性能

IMPROVEMENT OF THE KINETIC PROPERTIES OF MINi3.7Co0.6Mn0.4Al0.3 HYDRIDE ELECTRODE BY TREATMENT OF AN ALKALINE SOLUTION CONTAINING POTAS SIUM BOROHYDRIDE

研究了用表面改性处理对ＭＩＮｉ３．７Ｃｏ０．６Ｍｎ０．４Ａｌ０．３贮氢合金电极动力学性能的影响．结果表明：用含 ＫＢＨ４碱液处理合金粉末可有效地提高氢化物电极的高倍率放电能力 ＨＲＤ，交换电流密度Ｉ０，极限电流密度ＩＬ和α相中氢的扩散系数Ｄ等各项动力学性能，而且ＫＢＨ４的浓度越高（＜０．０３ ｍｏｌ／Ｌ），动力学性能提高得也越大当碱液中所含 ＫＢＨ。浓度相同时氢在相中的扩散系数Ｄ的增加要小于交换电流密度Ｉ０的增加． ＫＢＨ４碱液处理对 ＭＩＮｉ３．７Ｃｏ０．６Ｍｎ０．４Ａｌ０．３贮氢合金电极动力学性能的改善导致合金电极的阴。

The effect of the powder of alloy electrode treated by 6 mols/L KOH solution containing y mosl/L KBH4 (y=0.0, 0.005, 0.01, 0.02, and 0.03) on the kinetic properties of electrode has been systematically studied. The results show that kinetic properties of electrode, including high rate dischargeablilty HRD, exchange current density I0s, limiting current density IL, diffusion coefficient of hydrogen in phase D have been improved markedly after treatmenst. Furthermore, the higher the concentration of KBH4, the better the kinetic properties are. The improvement of diffusion coefficient of hydrogen in or phase D. is lower than that of exchange current density IO when the concentration of KBH4 is constant. This improvement of kinetic properties leads to the decrease of overpotential of anodic and cathodic polarization.