α型和β型PbO_2正极的充放电性能比较

A Comparative Study of Charge-Discharge Behaviors of α-PbO_2 and β-PbO_2 Cathodes

利用化学合成法分别制得α-PbO2和β-PbO2样品,采用XRD、SEM表征与观察两种不同晶型的PbO2样品.由两种晶型PbO2粉末做成铅酸电池的活性正极,采用循环伏安、恒电流充放电以及电化学阻抗谱等电化学方法研究了其电化学性能.结果表明,α-PbO2电极的放电容量较低,β-PbO2电极的放电容量较高,两种晶型PbO2粉末按不同配比制成复合电极有利于提高铅酸电池正极的充放电性能.

The α-PbO2 and β-PbO2 powders were prepared using simple chemical synthetic methods, and their crystalline structures and surface morphologies were characterized with X-ray powder diffiaction spectroscopy （XRD） and scanning electron microscopy. Using the as-synthesized α-PbO2 and β-PbO2 powders as positive active materials,the electrochemical performance of the two PbO2 materials was investigated by means of cyclic voltammetry, galvanostatic charge-discharge tests and electrochemical impedance spectroscopy. The results indicate that the discharge capacity of α-PbO2 electrode is larger than that of β-PbO2. Moreover, the composite electrode made by α-PbO2 and β-PbO2 mixtures with different proportions are favorable for enhancing the charge-discharge cycle performance of PbO2 positive electrode.