采用线性电位扫描(LSV)、电镜扫描(SEM)、交流阻抗(AC)及电感耦合等离子体原子发射光谱(ICP)测试技术研究了铅电极和不同铋含量的铅铋合金电极在硫酸溶液中氧化膜的生成情况。由恒电位0.9 V 20 m in后的线性电位扫描伏安曲线中PbO+PbO.PbSO4和PbSO4还原电量可知,铅(Ⅱ)氧化膜生成量在铋质量分数低于0.103%时不受铋含量的影响,但铋含量较高时,随铋含量增加而增长;由电阻与电位的关系曲线可知,铋含量较高时,随铋含量增加,氧化膜电阻减小,电导增强;在1.6 V恒电位20 m in后的线性电位扫描伏安曲线表明,铋对PbO2的生成影响规律与铅(Ⅱ)氧化膜的相同;电镜扫描显示,生成的氧化膜随铋含量增长,结构更加疏松;ICP分析表明,不同含量铅铋合金电极中铋溶出量,随铋含量增加而增加。
The stoichiometric alloy MlB5.0 and the hypo-stoichiometric alloy MlB4.85 were prepared by twin-roller rapid quenching process, and their structure and electrochemical properties were studied. The results of XRD show that both of the alloys have a typical single-phase hexagonal CaCus-type structure. The cell volume of the hylpo-stoichiometric alloy M1B4.85 is slightly larger than that of the stoichiometric alloy M1B5.0, although its lattice constant cla is smaller. Under 2 C discharging rate, i.e. 640 mA/g, the M1B4.85 has a discharge capacity of 320 mAh/g, which is higher than that of the M1Bs.o, 312 mAh/g. Nevertheless, the capacities of the M1B4.85 and the M1Bs.o decline 24.7% and 20.2% after 400 cycles, respectively. The relationship of electrochemical performances of the alloys with their structures is discussed.
