Acenaphthenequinone: From a Dissolving Cathode to a Cycling‐Stable Cathode via Molecular Engineering

Comprehensive Summary Quinone‐based cathode materials demonstrate considerable prospect for lithium‐ion batteries (LIBs) due to their cost‐effectiveness, excellent electrochemical reversibility and good chemical stability. Notably, acenaphthoquinone (ANQ), as a readily available quinone unit, has not been reported as a viable cathode material for LIBs. In fact, ANQ is a distinctive and compelling quinone unit because of its stable structure and high theoretical specific capacity, yet the severe dissolution in electrolytes hinders its application. To address this issue, 1,4‐bis(1,2‐acenaphthoquinonyl)benzene (BAB) is designed by expanding the molecular size, while 2,5‐bis(1,2‐acenaphthoquinonyl)pyrazine (BAP) is further engineered based on BAB's structure to improve planarity. They manifest significantly suppressed solubilities owing to the enhanced intermolecular forces, with BAP exhibiting an even more pronounced reduction. As a result, the BAP cathode demonstrates exceptional electrochemical performance including a high specific capacity of 220.9 mAh·g −1 at 0.2 C, and remarkable cycling stability, with 84.4% capacity retention over long‐cycling of 1000 times at 2 C, marking the first successful accomplishment of stable cycling in ANQ‐derived electrode materials. These results validate the effectiveness of our molecular engineering strategy and this work focusing on ANQ fills a critical gap in the current landscape of quinone organic electrode materials.