Carbonyl Bridge Based p-pi Conjugated Polymers as High-performance Electrodes of Organic Lithium-ion Batteries.

Organic redox compounds have shown promising potential as electrode materials for lithium-ion batteries. Polymerization is an effective and feasible method to prevent rapid capacity decay. However, present conjugated polymers and non-conjugated polymers have their own limitations to constructing stable and high-performance electrodes. Herein we report a novel polyimide NDI-O which is connected by carbonyl bridges. The NDI-O is the p-pi conjugated polymer that exhibits a high energy density of 542 W h kg(-1) at 0.1C (1C=257 mA g(-1)) and ultrahigh power density of 14000 W kg(-1) due to its intriguing electronic properties. The combination of molecular electrostatic potential calculations and ex situ technologies reveals the lithium-ion storage mechanism during charge and discharge process. The orbital distribution calculations and electrochemical impedance spectroscopy tests have been shown to verify the excellent kinetic properties of NDI-O. This work expands the scope of polymers applied for LIBs and provides new methods to construct high-performance electrode materials for sustainable batteries.