3. Results and discussion
3.1. Characterization of leady oxides
As shown in Fig. 3(b), the XRD patterns of self-synthesized leady oxides specimens indicate that they mainly comprise b-PbO and aPbO with little amount of Pb and Pb3O4. The SEM images of the selfsynthesized leady oxides are shown in Fig. 3(a). The micromorphology of the leady oxides can be perceived as a porous structure with ultrafine particles, which provide more contact areas for electrochemical reaction of the active materials, and benefits for the increase of capacity.
Other physicochemical characteristics of leady oxides are summarized in Table 2. It can be seen that the apparent density of selfsynthesized leady oxide is much lower than the traditional ballmilled leady oxide, which was provided by Wuhan Changguang Power Sources. Co. Ltd. The degree of oxidation (oxidizability) ranges from about 70 to 85 wt%. Owing to the porous structure shown in Fig. 3(a), the specific surface area of self-synthesized leady oxides is much higher. Therefore the self-synthesized leady oxides exhibit much higher water absorption value and acidabsorption value than traditional leady oxide and could show higher initial discharge capacity potentially.