Polydopamine‐Assisted Synergistic Regulation of Surface Chemistry and Pore Architecture in Petroleum Coke‐Derived Carbons for High‐Power Sodium‐Ion Batteries

ABSTRACT Petroleum coke (PC) is an attractive carbon precursor for sodium‐ion batteries (SIBs) due to its high carbon content and low cost. However, the intrinsic graphitization tendency at elevated temperatures hampers Na ion storage and diffusion, thereby substantially compromising its Na‐storage performance. Herein, an innovative polydopamine (PDA)‐assisted modification strategy is proposed to synergistically regulate the surface functionalization and closed pore architecture in petroleum coke‐derived carbon. The dopamine‐derived N‐doping carbon layer not only alters the surface chemistry of petroleum coke‐derived porous carbon, enriching Na‐affinitive sites, but also enables a controllable transformation from open pore to a closed‐pore structure. Consequently, the modified PDAC‐2 material featuring optimized closed‐pore structures and uniform nitrogen doping delivers a reversible Na‐storage capacity of 352.8 mAh g −1 and an initial Coulombic efficiency (ICE) of 81.3%, along with remarkable cycle and rate capability. When paired with commercial O3‐NaNi 1/3 Fe 1/3 Mn 1/3 O 2 cathode, the assembled O3‐NaNi 1/3 Fe 1/3 Mn 1/3 O 2 //PDAC‐2 sodium‐ion full cell achieves a power density of 5450 W kg −1 at the energy density of 45.4 Wh kg −1 based on the total mass of cathode and anode. This work provides a novel approach for the value‐added utilization of petroleum coke and opens new avenues for the development of high‐performance anode materials for SIBs.