Significantly improved high-rate partial-state-of-charge performance of lead-acid batteries induced by trace amount of graphene oxide nanosheets

Abstract

• Trace amount of GONs is incorporated into the NAMs of LABs through a novel and simple way. • The NAMs containing 2 ppm GONs presents a spongy-like structure composed of porous Pb sticks. • Sulfation is suppressed due to the acceleration of the redox reaction between Pb and PbSO 4 . • The HRPSoC cycling life of the simulated cell increased by more than 1.4 times to 29,971 cycles. • The hydrogen generation almost has not any improvement because of the trace GONs content. In this work, trace amount of graphene oxide nanosheets (GONs) is incorporated into the negative active materials (NAMs) of lead-acid batteries (LABs) using an innovative and simple way. The effect of GONs on the morphologies, structures and compositions of the synthesized GONs-containing NAMs are investigated. It is observed that after formation, the NAMs containing 2 ppm GONs presents a spongy-like structure comprised of one-dimensional (1D) porous Pb sticks. Such a 1D structure of Pb sticks provides fast electron transport channel, while the pores on Pb sticks and the voids among Pb sticks facilitate electrolyte transportation. Therefore, accumulation of PbSO 4 crystals is greatly suppressed. Several electrochemical methods such as cyclic voltammetry and electrochemical impedance spectroscopy are used to understand the enhancement mechanism. It is found that the high-rate partial-state-of-charge (HRPSoC) cycling life of the simulated cell is increased by more than 1.4 times from 21,305 to 29,971 cycles. Although the electrochemical performance of NAMs is significantly improved, the hydrogen generation does not have any promotion because of the trace GONs content. The results demonstrate that our method is of great convenient and ultra-low cost with feasibility in large-scale application in LABs industry. Significantly improvement on the electrochemical performance of NAMs by incorporation of trace amount of GONs.