Synergistic Molecular Modulation of ππ Stacking for High‐Performance Pitch‐Derived Hard Carbon Anodes

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Hard carbons (HCs) from low‐cost pitch are promising anodes for sodium‐ion batteries, yet their performance is limited by the strong tendency of constituent polycyclic aromatic hydrocarbons (PAHs) to form ordered, graphitizable stacks. Prevailing pre‐oxidations typically fail to sufficiently disrupt these intrinsic ππ interactions. Here, we report a synergistic molecular strategy that deconstructs this order. We combine a mild sulfonation with the introduction of meso‐tetra(4‐carboxyphenyl)porphyrin (TCPP), which binds to PAH surfaces via face‐on ππ stacking. This interaction disrupts molecular packing and enhances sulfonation efficiency, yielding a 6‐fold increase in sulfur incorporation. During pyrolysis, the modified precursor follows an altered kinetic pathway where sulfonic groups create a covalent network and TCPP acts as a pore former, collectively suppressing graphitization. The resulting HC features an expanded interlayer spacing (0.371 nm), maximized closed‐pore volume, and a highly disordered structure. The optimized anode delivers a high reversible capacity (310 mAh g −1 ), superior plateau capacity (209 mAh g −1 ), excellent rate capability (205 mAh g −1 at 2 A g −1 ), and stable cycling. A full cell with a Na 3 V 2 (PO 4 ) 3 (NVP) cathode achieves 104.3 mAh g −1 at 0.1 C. This work establishes a cooperative molecular‐modulation approach to tailor carbonization kinetics, providing a general design principle for high‐performance HCs.

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