论文部分内容阅读
采用机械合金化方法制备了Mg2Ni纳米材料。不同扫描速度/温度下的循环伏安测试结果表明:样品的氧化峰电位随扫描速度的加快而正移;室温下的吸氢性能显著增强,吸放氢速度随温度的升高而加快。X射线小角散射结果表明:该材料具有1～5nm以及5～10nm的粒度分布,较小的粒度使得吸放氢反应的活性位置增多和放氢的扩散路径减少,这可能是导致材料贮氢性能显著提高的原因。循环寿命的快速检测结果表明:Mg2Ni纳米贮氢合金电极的活性很好;经过200次循环后,其容量保持率为66%。在电极一侧涂覆环氧树脂后其电化学活性未受到明显影响,容量保持率优于未涂覆的电极;但阴极峰和阳极峰电流值显著下降,说明吸放氢反应的速率以及充放电程度有所降低。
Mg2Ni nanomaterials were prepared by mechanical alloying. Cyclic voltammetry at different scan rates / temperatures showed that the oxidation peak potential of the samples shifted positively with the increase of the scanning speed. The hydrogen absorption performance at room temperature was significantly enhanced, and the hydrogen evolution rate was accelerated with the increase of temperature. Small-angle X-ray scattering results show that the material has a particle size distribution of 1 ~ 5nm and 5 ~ 10nm. The smaller particle size increases the active site of hydrogen absorption and desorption and reduces the diffusion path of hydrogen releasing, which may be the result of the hydrogen storage property Reasons for significant improvement. The rapid test of cycle life shows that Mg2Ni nanocrystalline hydrogen storage alloy has good electrode activity. After 200 cycles, its capacity retention is 66%. The electrochemical activity of the epoxy resin coated on one side of the electrode was not significantly affected, and the capacity retention rate was better than that of the uncoated electrode. However, the peak current of the cathode and the anode decreased significantly, indicating the rate of hydrogen absorption and desorption The degree of discharge has been reduced.