Lead single atoms anchored on reduced graphene oxide as multifunctional additive for lead–carbon battery

Abstract

The application of lead–carbon batteries (LCBs) in hybrid electric vehicles and large-scale energy storage was limited by gradual sulfation and parasitic hydrogen evolution reaction (HER) of negative plates. Here, Pb single atoms anchored on reduced graphene oxide (PbSAs@rGO) were prepared through electrostatic adsorption and thermal reduction method, and confirmed by two aberration-corrected transmission electron microscopy (TEM and STEM) and synchrotron-based X-ray absorption fine structure spectroscopy (XAFS). By anchoring PbSAs on rGO surfaces where HER is prone to occur, the HER rate was greatly reduced. Moreover, PbSAs could serve as seeds to induce three-dimensional growth of Pb branches, which endows the NAM containing PbSAs@rGO additives with a specific surface areas (SSA) about 2.3 times than that of control one. The increased SSA can help to delay the sulfation of negative plate. Meanwhile, PbSAs can help enhance the affinity of rGO towards negative active material (NAM), which enable electrochemical reduction reaction proceeds at a higher rate. Thanks to the coordination of various functions from multifunctional additives, service life of LCBs under high-rate partial-state-of-charge (HRPSoC) have been extend from 3529 to 16,097 cycles, and from 4692 to 22,606 cycles, in 50% state of charge (SoC) and 75% SoC, respectively.