An Insoluble Amino-Functionalized Hexaazatriphenylene as Stable Organic Cathode in Lithium-Ion Batteries

Abstract

Organic electrode materials have received increasing attention in rechargeable batteries due to their earth abundance and variable structures. However, the practical application of most organic electrode materials is limited by the high solubility in the electrolyte. Herein, an insoluble amino-functionalized hexaazatriphenylene (defined as HATN-[NH2]3) in the electrolyte is developed as stable organic cathode material for lithium-ion batteries (LIBs). The resultant HATN-[NH2]3 electrode achieves a high reversible capacity of 192.5 mAh g−1 at a current density of 0.05 A g−1. Remarkably, the electrode exhibits almost no capacity fade after 500 cycles at 0.5 A g−1. The high stability can be ascribed to insoluble property caused by hydrogen bonds between HATN-[NH2]3 molecules. Moreover, density functional theory calculations suggest that amino functionalization can reduce the band gap of HATN, in favor of improved conductivity and thus enhanced rate performance. This work offers a simple but efficient strategy to develop stable organic electrode materials in LIBs and beyond.