Layered Copper-Anthraquinone Coordination Polymer Cathode Leveraging Dual-Redox Sites and Facilitated Ion Diffusion...

Organic electrode materials often face challenges of low electronic conductivity and high solubility in electrolytes. To address this, we synthesized Cu-DHAQ, a layered metal-organic coordination polymer using 1,4-dihydroxyanthraquinone (DHAQ) as the ligand and Cu²⁺ as the metal center. Coordination polymerization effectively suppresses DHAQ dissolution and enhances cycling stability. The extended π-conjugated framework promotes charge delocalization, improving conductivity, while the layered structure facilitates Li⁺ diffusion. Cu-DHAQ features dual redox-active centers (Cu²⁺/Cu⁺ and C═O/C─O^-), enabling a three-electron transfer reaction. Benefiting from these synergistic effects, the Cu-DHAQ cathode delivers a high discharge capacity of 260.5 mAh g^-1 with 81.2% retention after 100 cycles, and maintains 119.4 mAh g^-1 at 0.5 A g^-1. Furthermore, both coin and pouch full cells using Cu-DHAQ cathode and pre-lithiated hard carbon (Li-HC) anode were successfully demonstrated, highlighting its potential as a high-performance organic cathode material for lithium batteries.