Multifunctional perfluorooctanoic acid as electrolyte additive enables high-performance lead–carbon battery

Abstract

Lead–carbon batteries (LCBs) have shown potential in mitigating the irreversible sulfation commonly seen in lead-acid batteries. However, the application of LCBs is limited by issues such as hydrogen evolution side reactions (HER) and suboptimal long-term cycling performance. In this study, perfluorooctanoic acid (PFOA) is selected as a multifunctional additive to improve battery performance through economical electrolyte modification. Battery and electrochemical tests demonstrate that PFOA promotes uniform lead sulfate nucleation, reduces charge transfer resistance at the electrode–electrolyte interface, and strengthens the hydrogen bonding network. The overall performance of LCBs is significantly improved due to a synergistic effect between activated carbon and PFOA, effectively inhibiting sulfation, preventing hydrogen evolution, and maintaining the lead–carbon connection structure. With the addition of PFOA, the cycle life under high-rate partial state of charge (HRPSoC) and capacity retention at 80% depth of discharge (DOD) increase by 213.9% and 49.3%, respectively.