金属氢化物镍蓄电池储存稳定性研究

Study on the storage stability of nickel metal hydride battery

借助X射线衍射仪(XRD)和扫描电子显微镜法(SEM)对金属氢化物镍蓄电池在不同储存条件下性能的变化及影响进行了对比性研究,同时探讨了造成金属氢化物镍蓄电池在不同条件下储存期间性能下降的原因。结果表明:电池经不同条件储存后,电池的质量略微下降,内阻增加,开路电压变小,容量发生不可逆衰减,充电平台出现了不同程度的上升,其中50℃条件下储存的电池性能最差;经过XRD和SEM分析发现,在储存过程中,电池负极活性物质储氢合金粉发生了不同程度的粉化,正极活性物质球镍的结构也发生了不同程度的破坏。

The influence of different conditions on the properties of nickel metal hydride battery was studied by X-ray diffraction （XRD） and scanning electron microscope （SEM）, and the reasons for the performance reduction were discussed. The results show that there is a slight mass drop of the battery after being storaged under different conditions. Meantime, the inner resistance increases and the open-circuit voltage decreases. In addition, there is an irreversible capacity loss and elevation of charge platform. The worst performance was observed when the battery was stored at 50 ℃. The XRD pattern and SEM images indicate that the capacity degradation of nickel metal hydride batteries are caused by the defects and disorder in crystal structure of active mass in negative and positive electrodes.