A π-conjugated organic compound with multiple active sites as a cathode material for high-rate aqueous zinc-ion batteries

Abstract

Aqueous zinc-ion batteries (AZIBs) have attracted much attention for owing to their environmental friendliness, low cost and high safety. Organic compounds have emerged as promising cathode materials for AZIBs due to their abundance of active sites, structural tunability and renewability. Here, a new π-conjugated compound with multiple active sites tris(3-amino-1,2,4-triazolyl) hexaazatriphenylenehexacarboxy triimide (TAT-HATTI) is prepared and evaluated firstly as a cathode material for AZIBs. The TAT-HATTI electrode displays a high discharge specific capacity (531 mAh g−1 at 0.05 A g−1), high-rate performance and better cycle stability (capacity retention of 78 % after 1000 cycles at 2 A g−1). The research results reveal that the electrode reaction mechanism involves insertion/extraction of Zn2+ and H+ ions. Impressively, the assembled flexible aqueous Zn//TAT-HATTI battery exhibits the higher volumetric energy density (4.4 mWh cm−3), high-rate capability, better cycle stability and superior flexibility, owning an application potential in wearable electronics.