Porphyrin Integration Enhances Bipolar Redox Accessibility for High‐Rate Sodium‐Based Dual‐Ion Storage

ABSTRACT

Closing the gap between theoretical multielectron capacity and practical accessibility remains the central bottleneck for high‐energy organic batteries. Herein, we report a molecular design strategy that integrates a porphyrin motif into a sulfur‐rich conjugated polymer (BTTP) to align electronic structure, state‐dependent ion interactions, and electrochemical kinetics across the bipolar window. Despite possessing a lower theoretical capacity than its reference counterpart (BTB), BTTP achieves an exceptional theoretical capacity utilization of 94.2% (delivering 477 mAh g ⁻¹ at 0.5 A g ⁻¹ , compared to only 53.5% and 351 mAh g ⁻¹ for BTB). Electrokinetic analyses, including GITT and DRT, confirm accelerated apparent ion diffusion and reduced polarization limitations, enabling BTTP to retain 166 mAh g ⁻¹ at an ultrahigh current density of 20 A g ⁻¹ over 25 000 cycles. Operando/ex situ spectroscopy and theoretical calculations elucidate that the dual pyrrolic/imino nitrogen sites in porphyrin and the sulfur‐rich backbone cooperatively provide potential‐dependent coordination environments for PF ₆ ⁻ anions and Na ⁺ cations. This work suggests that molecular regulation of complementary ion‐interaction environments within multi‐active‐unit frameworks, rather than simply increasing the number of redox units, is important for enhancing rate capability and capacity utilization.