Enabling stable cycling performance with rice husk silica positive additive in lead-acid battery

Lead-acid battery has been widely used in stationary energy storages, such as photovoltaic application, grid service and uninterrupted power system due to the advantages of high safety, recyclability, and low cost. However, the low cyclic performance limits its further applications in emerging functions. One of the main failure modes is caused by the high polarization on the PbO2 positive plate. Herein, the rice husk silica with hierarchical porous structure was used as the positive additive for preventing from the high polarization of the PbO2 positive plate. Nitrogen adsorption-desorption isothermal and X-ray diffraction confirmed that the hierarchical porous rice husk silica enlarged the electrochemical surface area of the PbO2 positive plate, endowing a high rate of active material utilization and low polarization during the charging process. Compared with the blank plate, the PbO2 plate with rice husk silica showed improved Coulombic efficiency and a prolonged cycle life. These notable features verify that the porous rice husk silica is a cost-effective positive additive for sustained lead-acid batteries.