Carbonyl Bridge-Based p-π 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 nonconjugated 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 a p-π conjugated polymer that exhibits a high gravimetric energy density of 542 W h kg and an ultrahigh power density of 14,000 W kg due to its intriguing electronic properties. The combination of molecular electrostatic potential calculations and ex situ technologies reveals the lithium-ion storage mechanism during the charge and discharge processes. 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.