As one of the most promising candidates in alkaline secondary batteries,CoB amorphous alloy has high reversible discharge capacity,but it exhibits poor properties at low or high temperature,which needs urgent improvement for practical application.The rare earth-based La0.7Mg0.3Ni3.5 alloy (represented as LaMgNi) was prepared via induction melting and CoB amorphous alloy (represented as CoB) was synthesized via chemical reduction method.CoB-LaMgNi composite alloy was obtained by ball milling process.The effects of rare earth alloys on electrochemical properties of CoB alloy in wide temperature range were studied.The phase structure and surface morphology were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).Moreover,the electrochemical performance was characterized by charge-discharge test,potentiostatic step discharge,high-rate discharge ability (HRD),electrochemical impedance spectroscopy (EIS),linear polarization (LP) and anodic polarization (AP).The experimental results show that the electrochemical properties at wide temperature range are remarkably improved after the addition of LaMgNi alloy.%CoB类非晶合金具有较高的可逆放电容量,是碱性二次电池的理想负极材料,但是其高低温电化学性能亟待改善.采用化学还原法和感应熔炼法分别制备CoB类非晶合金(以CoB表示)和稀土基La07Mg.3Ni.5合金(以LaMgNi表示),再利用机械球磨法将所制得的LaMgNi合金和CoB合金进行充分混合,获得CoB-LaMgNi复合合金,研究了稀土基LaMgNi合金的添加对CoB合金的宽温区电化学性能的影响机制.采用×射线衍射(XRD)和扫描电子显微镜(SEM)分别对所制备的合金进行物相分析和表面形貌分析.合金电极的电化学性能利用恒电流充放电循环、恒电位阶跃放电、高倍率放电(HRD)、电化学交流阻抗(EIS)、线性极化(LP)、阳极极化(AP)等进行测试.实验结果表明,稀土基LaMgNi合金的添加可以显著改善CoB非晶合金的宽温区电化学充放电性能.
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