▎ 摘　　要

Lead sulfate/graphene nano sheets (GNS) composites were fabricated by using a simple impregnation method. The composite was used as a negative active material for lead acid battery. Compared with pure lead sulfate electrodes, the composite electrodes display higher specific capacity and rechargeable performance under high charge and discharge rates. An average discharging specific capacity of PbSO4/GNS composites reaches 110, 94 and 69 mAh.g(-1) at current density of 100 mA.g(-1), 200 mA.g(-1) and 300 mA.g(-1), respectively. However, the average discharging capacity of PbSO4 only reaches 49, 5 and 0.5 mAh.g(-1) at the same condition. The electrochemical characteristic of the composites electrode was studied by cyclic voltammetry (CV) and battery tests. The cyclic voltammetry results show that capacitive effect and the hydrogen evolution of graphene nano sheets become more obvious with the increase in scanning rate resulting in 20% lower charging efficiency of PbSO4/GNS composites compared to lead sulfate. The battery charge-discharge curves confirm that graphene nano sheets improve the charging voltage about 0.1 V and can also help double the capacity of lead sulfate. The XRD and SEM results show that lead sulfate particles are well dispersed on the surface of graphene nano sheets instead of agglomerating.