Synthesis of Nafion-reduced graphene oxide/polyaniline as novel positive electrode additives for high performance lead-acid batteries

Abstract

Graphite oxide (GO) has rich oxygen-containing functional groups and active site, which can significantly improve the utilization of its active substances as a positive electrode additive for lead-acid batteries. However, during the charging and discharging cycle, some GO is oxidized and decomposed, resulting in a weakened electrical connection between the positive active material particles and a decrease in battery performance. To enhance the functionality and efficacy of GO, this study initially synthesized a precursor of Nafion-reduced graphene oxide/polyaniline (NGP). Subsequently, layered NGP (HNGP) composite materials were prepared using polystyrene spheres as sacrificial templates. These HNGP composites were employed as additives for the positive electrodes of lead-acid batteries. The rate performance tests conducted at 0.05, 0.1, 0.2, 0.5, and 1 C revealed that the discharge specific capacities of the control sample and the positive electrode of the lead-acid battery incorporating the novel additive were 104.76, 77.28, 74.59, 64.23, 51.22 mAh g−1 and 187.37, 168.56, 117.44, 95.65, 83.78 mAh g−1, respectively. The remarkable conductivity and intricate porous structure of HNGP expedite the migration of positive electrode electrons and the diffusion of ions in the electrolyte within the electrode plate, thereby augmenting reaction kinetics and substantially elevating the discharge capacity and rate performance of the battery.