Conjugated diketone-linked polyimide cathode material for organic lithium-ion batteries

Aromatic polyimides have been considered promising organic cathode materials for lithium-ion batteries (LIBs) due to their excellent solvent resistance, superior electrochemical capability and highly designable structure. However, the inferior intrinsic conductivity and limited redox-active sites lead to their suboptimal comprehensive electrochemical performance and restrict their applications in LIBs. Herein, a novel conjugated diketone-based polyimide (PTN) cathode material with multiple carbonyl redox sites is proposed and prepared for LIBs. The integration of electron-withdrawing pi-conjugated diketone with naphthimide can effectively regulate the electronic structure and elevate the working potential of the polyimide-based cathode, and improve its comprehensive electrochemical performance. The PTN-based cathode delivers a high specific capacity of 213.4 mAh g(-1), excellent cycling stability (97.3% capacity retention after 2000 cycles at 2000 mA g(-1)) and high rate performance (78.2% capacity retention at 2000 mA g(-1) vs. 50 mA g(-1)), high gravimetric energy density (380 Wh kg(-1)) at a high power density (4417 W kg(-1)) simultaneously. This comprehensive electrochemical performance is among the best results of reported polyimide cathode materials and suggests that PTN has great potential in energy storage applications.

Automated summary

PTN, a conjugated diketone-based polyimide cathode material with multiple carbonyl redox sites, shows high specific capacity, excellent cycling stability, high rate performance, high gravimetric energy density, and high power density, indicating great potential in energy storage applications.