Bonding evolution in PbO@C composites for lead-carbon battery: Implications for HRPSoC performance

Abstract

Due to the huge density difference between lead and carbon, the strength of the bonding between lead and carbon materials plays a key role in lead-carbon batteries (LCBs). Here, the evolution and transformation of Pb and C bonding in the negative active materials (NAMs) were studied throughout the battery fabrication process of curing, formation and charge/discharge cycles. The results indicate PbC bond in the PbO@C composite is cleaved by chemical reactions during the curing and formation process. In addition, the graphitization degree of the carbon material decreased after charge/discharge cycles. Compared with the blank lead-acid battery, the initial capacity and high-rate partial state of charge (HRPSoC) cycle life of lead-carbon with PbO@C composite significantly increase. The previous sites of Pb and C after the transformation of lead and its compounds can still act as active sites for the reaction of NAMs in curing, formation and charge/discharge cycles. Meanwhile, the porous carbon material in PbO@C can act as a supporting skeleton and a 3D electroosmotic pump, which is beneficial for the interaction between the electrolyte and the negative electrode active substance, attributing to the boosted performance of lead-carbon battery. This work provides theoretical support for understanding the lead-carbon binding mechanism during the operation of lead-carbon batteries.