Insight into the Double Redox-Active Centers of Porphyrin-Anhydride-Based Polymer Cathode for Dual-Ion Organic Batteries

Organic cathode materials have garnered extensive application in energy storage systems, owing to their cost-effectiveness, environmental compatibility, and sustainable renewability. However, the high solubility of these materials in electrolytes and their inherently low conductivity have limited their electrochemical performance. Herein, this work presents an effective strategy to assemble the hyper-cross-linked polymer (CuTPP-PMDA-HCP) by integrating copper tetraphenylporphyrin with pyromellitic dianhydride. CuTPP-PMDA-HCP not only mitigates the dissolution of organic species into the electrolyte but also enhances its overall conductivity. As expected, CuTPP-PMDA-HCP exhibits a remarkable reversible capacity of 266.5 mA h g^–1 at 0.2 A g^–1, excellent cycle rate capability, and robust cycling performance (101 mA h g^–1 after 1200 cycles at 5 A g^–1). Meanwhile, the mechanism of the CuTPP-PMDA-HCP cathode serving as double redox-active centers for hosting both anions (PF₆^–) and cations (Li⁺) in typical dual-ion organic batteries is investigated by comprehensive experimental analysis and density functional theory calculations. Our findings offer a promising approach for developing high-performance and cost-effective organic cathodes for energy storage applications.