Nine-Electron Transfer of Binder Synergistic π-d Conjugated Coordination Polymers as High-Performance Lithium Storage Materials

Angew Chem Int Ed Engl. 2023 Jan 23;62(4):e202215864. doi: 10.1002/anie.202215864. Epub 2022 Dec 16.

Abstract

To solve the problems such as the dissolution and the poor conductivity of organic small molecule electrode materials, we construct π-d conjugated coordination polymer Ni-DHBQ with multiple redox-active centers as lithium storage materials. It exhibits an ultra-high capacity of 9-electron transfers, while the π-d conjugation and the laminar structure inside the crystal ensure fast electron transport and lithium ion diffusion, resulting in excellent rate performance (505.6 mAh g-1 at 1 A g-1 after 300 cycles). The interaction of Ni-DHBQ with the binder CMC synergistically inhibits its dissolution and anchors the Ni atoms, thus exhibiting excellent cycling stability (650.7 mAh g-1 at 0.1 A g-1 after 100 cycles). This work provides insight into the mechanism of lithium storage in π-d conjugated coordination polymers and the synergistic effect of CMC, which will contribute to the molecular design and commercial application of organic electrode materials.

Keywords: Coordination Polymers; Electrode Materials; Lithium-Ion Batteries; Nine-Electron Transfer; Synergistic Effect.