Oxidized indanthrone as a cost-effective and high-performance organic cathode material for rechargeable lithium batteries

Despite the numerous reports on organic cathode materials for rechargeable batteries, it is a huge challenge to simultaneously satisfy energy density and cycling stability, mainly due to the dissolution in aprotic electrolytes. Herein, we report a novel small molecular organic cathode material (SMOCM), namely oxidized indanthrone (oIDT), synthesized via a simple oxidation of industrially available indanthrone (IDT). Benefiting from the extensive aromatic nucleus and oxidation of unfavorable dihydropyrazine moiety to useful pyrazine, it achieves superior comprehensive electrochemical performance to other SMOCMs for lithium batteries so far reported, including a high energy density (273 mAh g–1 × 2.45 = 668 Wh kg–1) and excellent capactiy retension under high current rate (75% @ 2000 mA g–1) or after long-term cycling (76% @ 1000th cycle). Additionally, the investigation also provides insightful mechanism understandings on the redox reaction and electrode evolution of SMOCMs.