Utility lead-carbon batteries in renewable energy storage applications require fast charge ability and long-term cycling stability, which introduces a fundamental problem that how to improve the electrode kinetics and cycling stability of lead-carbon electrode. Herein, we present an oxygen-deficient PbO decorated rice-husk-based hierarchical porous carbon (RHHPC@PbO1-x) composite as an effective additive of negative electrode in lead-carbon battery. The RHHPC@PbO1-x composite was prepared from a facile sol-gel/annealing method. The obtained RHHPC@PbO1-x composite and the lead-carbon electrode with RHHPC@PbO1-x additives were characterized by various physicochemical methods, such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and multiple electrochemical methods. The RHHPC@PbO1-x composite enhances the electrochemical active surface area and strengthens the structural stability of lead-carbon electrode, which improves the electrode kinetics and the cycling stability of lead-carbon negative electrode. As a result, the cycling life of a 2 V/4 Ah valve-regulated lead-carbon battery with RHHPC@PbO1-x composite additives exhibited a lifespan of 900 cycles (triple of the blank battery). Our work gives an insight for interphase and porosity tuning of lead-carbon additives used in lead-carbon battery. Based on the existing mature production facilities of lead-acid battery, it is promising for this RHHPC@PbO1-x additive to be used in commercial lead-carbon batteryies for renewable energy storage.