An all-organic symmetric battery base on a triquinoxalinylene derivative with different redox voltage active sites and large conjugation system

Organic materials are considered to have broad application prospects in energy storage system due to their strong designability and abundant resources. Here, we report a triquinoxalinylene derivative tribenzoquinoxaline-5, 10-dione (3BQ) containing high redox potential functional groups (C=O, C=N) and a large number of low redox potential functional group (unsaturated carbon). This paper use 3BQ as cathode and anode to assemble all-organic symmetric batteries. Since 3BQ has denser active sites and larger conjuated system than Triquinoxalinylene (3Q), the 3BQ cathode has an initial capacity of 506 mAh g-1 (Ctheo = 515 mAh g-1) at 0.2 C, the capacity of 3BQ and 3Q cathodes are 210 and 107 mAh g-1 after 300 cycles at 1 C. The large conjugated system and planar structure of 3BQ inhibits its dissolution in electrolyte and accelerates the charge transfer rate, bringing good cycle stability and rate performance for batteries. The all-organic symmetric batteries assembled with pre-lithiated 3BQ and pristine 3BQ deliver an initial capacity of 483 mAh g-1 at 0.2 C, a capacity of 172 mAh g-1 after 300 cycles and an energy density of 301 Wh kg−1. This work provides a strategy for the development of high-performance LIBs using organic materials as cathode and anode.