Novel core–shell structure of a lead-activated carbon (Pb@AC) for advanced lead–acid battery systems

To enhance the power and energy densities of advanced lead–acid batteries (Ad-LAB), a novel core–shell structure of lead-activated carbon (Pb@AC) was prepared and used as a negative electrode active material. The AC could be formed as a shell around a core of Pb nanoparticles. The active core–shell structures were synthesized using a simple chemical process to overcome the limitations in the negative Pb electrode, specifically the large crystallization of lead sulfate (PbSO₄) that leads to a short cycle life. The key role of the carbon material in the negative electrode is to enhance the electrochemical performances and decrease the formation of PbSO₄. The X-ray diffraction study reveals that the formation of lead oxide was prevented by the AC during the synthetic process. The novel core–shell structure of Pb@AC was confirmed through transmission electron microscopy. In order to obtain high-performance Ad-LAB, a high surface area of the AC is necessary to provide a super capacitive effect in the negative electrode. The unit cell performance of the as-prepared active materials exhibits significant increased discharge capacity at 1C rate. The unit cell with the Pb@AC negative electrode has a capacity per unit volume of 0.0165 Ah/cc. Hence, the low cost of AC and the simple synthetic core–shell structure of Pb@AC make this material a promising negative electrode active material for Ad-LAB applications.