Lead-acid batteries and lead–carbon hybrid systems: A review

Lead-acid systems dominate the global market owing to simple technology, easy fabrication, availability, and mature recycling processes. However, the sulfation of negative lead electrodes in lead-acid batteries limits its performance to less than 1000 cycles in heavy-duty applications. Incorporating activated carbons, carbon nanotubes, graphite, and other allotropes of carbon and compositing carbon with metal oxides into the negative active material significantly improves the overall health of lead-acid batteries. Carbons play a vital role in advancing the properties of lead-acid batteries for various applications, including deep depth of discharge cycling, partial state-of-charge, and high-rate partial state-of-charge cycling. Therefore, lead-carbon hybrid batteries and supercapacitor systems have been developed to enhance energy-power density and cycle life. This review article provides an overview of lead-acid batteries and their lead-carbon systems, benefits, limitations, mitigation strategies, and mechanisms and provides an outlook.