Graphitic carbon nitride/carbon coating on negative plate extends lead-acid batteries cycle life

Lead acid batteries operate more efficiently by increasing hydrogen evolution overpotential. Battery performance is enhanced by adding graphitic carbon nitride (g-C₃N₄) and carbon black (CB). The CB-g-C₃N₄ composite material inhibited hydrogen gas evolution by increasing the overpotential of the reaction. The bilayer configuration of g-C₃N₄ stabilized nitrogen defect sites in a planar arrangement, introducing an additional energy barrier. The 25% and 50% g-C₃N₄ exhibited elevated overpotential relative to pure carbon material, as elucidated by density functional theory. The research revealed a high rate-partial state of charge (HR-PSoC) cycle life of 58,000 and 47,000 cycles for 25% g-C₃N₄ and 50% g-C₃N₄, respectively, at 50% depth of discharge. These findings present an innovative enhancement for lead-acid batteries, specifically for Idle-Stop-Go (ISG) cars, resulting in superior performance and durability.