Rational Molecular Engineering of Amidonaphthoquinone Cathodes: Precise Hydrogen Bond and Size Control for...

Rational design of organic cathode materials with suppressed solubility is crucial yet challenging for achieving high-capacity and long-cycling rechargeable batteries. This study presents a facile synthesis strategy for three naphthoquinone derivatives (NQ1-NQ3) featuring tunable amide functionalities and molecular dimensions, followed by a systematic evaluation of their electrochemical performance in lithium-organic batteries (LOBs). The strategic incorporation of multiple amide motifs and molecular size expansion in NQ2 and NQ3 effectively enhances intermolecular interactions through hydrogen-bonding networks and π-π stacking, resulting in remarkable solubility suppression and superior cycling stability. Notably, the NQ3-based cathode demonstrates an intriguing structural evolution involving progressive particle pulverization during cycling, which facilitates intimate contact with conductive carbon additives and significantly improves electrode conductivity. These synergistic effects enable the best LOB performance of NQ3, such as a high specific capacity (224 mAh g^-1 at 0.1 A g^-1), good rate capability (162 mAh g^-1 at 2 A g^-1) and cycling stability, outperforming most reported organic cathode materials. This work provides molecular-level insights into suppressing dissolution through non-covalent interaction engineering for high performance LOBs.