Oxygen-functionalized defect engineering of carbon additives enable lead-carbon batteries with high cycling stability

摘要

Lead-acid batteries are potential candidates for large-scale energy storage because of their low cost, high safety, and high recyclability. However, lead-acid batteries fail prematurely under partial-state-of-charge conditions due to the severe sulfation of negative electrodes. Carbon-enhanced lead-carbon electrodes inhibit sulfation by boosting Pb deposition and PbSO4 dissolution processes. Nevertheless, the carbon additives show different af-finities to lead. Carbon additives with low affinity to lead result in inhomogeneous Pb deposition and a high rate of hydrogen evolution, which decreases the cycling stability of lead-carbon batteries. In this work, we improved the affinity of carbon to lead by introducing oxygen-functionalized defects onto a rice husk-derived hierarchical porous carbon (RHHPC). Compared with the original RHHPC, the oxidized RHHPC (ORC) boosts the redox reversibility for Pb deposition and dissolution by offering extra oxygen-functionalized defects, which enables the high cycling stability of the ORC lead-carbon battery. This work opens an avenue to enhance the redox reversibility and the cycling stability of lead-carbon batteries through defect engineering of carbon additives.