Theory-guided design of one-dimensional π-d conjugated coordination polymer with multiple redox-active sites for advanced sodium-organic batteries

Conjugated coordination polymers (CCPs) have garnered significant interest for diverse applications due to their ability to extend electron delocalization domains and enhance material conductivity. However, the precise synthesis of CCPs with tailored properties remains challenging owing to their complex and often uncontrollable reaction dynamics. In this study, we report the successful synthesis of a one-dimensional (1D) CCP, termed Co-DHBQ, using 2,5-dihydroxy-1,4-benzoquinone (DHBQ) as the organic ligand and cobalt as the central metal atom, following systematic screening of potential ligands via DFT calculations. The resulting material exhibits π-d conjugation, a laminar structure, and multiple redox-active centers, leading to exceptional electron transport and sodium diffusion capabilities. When evaluated as a battery electrode, Co-DHBQ delivers a discharge specific capacity of 299 mAh g −1 after 400 cycles at 500 mA g −1 , demonstrating remarkable cycling stability. Notably, the material exhibits a synergistic interaction with the CMC binder, enabling outstanding rate performance, even after high-current cycling (5000 mA g −1 ), the capacity remains recoverable upon returning to lower current densities. These findings underscore the potential of CCPs in high-performance batteries and provide a pathway toward the commercialization of organic electrodes. The 1D π-d conjugated coordination polymer Co-DHBQ exhibits an ultra-high sodium storage capacity of 7-electron transfer and excellent rate performance due to its multiple redox active centers, π-d conjugation and laminar structure. Meanwhile, the binder CMC, like an snake, has an appropriate interaction with both the ligand and Co 2+ of Co-DHBQ, thus reducing the solubility of Co-DHBQ and enhancing its cycle life.