Construction of Fluorine- and Piperazine-Engineered Covalent Triazine Frameworks Towards Enhanced Dual-Ion Positive Electrode Performance

Organic positive electrodes featuring lightweight and tunable energy storage modes by molecular structure engineering have promising application prospects in dual-ion batteries. Herein, a series of highly porous covalent triazine frameworks (CTFs) were synthesized under ionothermal conditions using fluorinated aromatic nitrile monomers containing a piperazine ring. Fluorinated monomers can result in more defects in CTFs, leading to a higher surface area up to 2515 m(2) g(-1) and a higher N content of 11.34 wt % compared to the products from the non-fluorinated monomer. The high surface area and abundant redox sites of these CTFs afforded high specific capacities (up to 279 mAh g(-1) at 0.1 A g(-1)), excellent rate performance (89 mAh g(-1) at 5 A g(-1)), and durable cycling performance (92.3 % retention rate after 500 cycles at 2.0 A g(-1)) as dual-ion positive electrodes.

Automated summary

In this study, a highly porous covalent triazine framework material was synthesized through molecular structure engineering as a positive electrode material for dual-ion batteries. The material exhibited high specific surface area, high nitrogen content, and good cycling performance, indicating promising application prospects.