A Donor–Acceptor‐Donor‐type Organic Molecule as an Effective Electrode to Form Rapid Diffusion Pathway for High‐Performance Sodium‐Ion Batteries

Abstract

AbstractCarbonyl‐containing organic electrodes have been widely considered as ideal substitutes for traditional inorganic compounds in sodium‐ion batteries (SIBs) due to their excellent redox reversibility and structural tunability. However, constructing effective Na+ diffusion channels in these materials is very challenging. To address this issue, we design a new organic molecule, N,N’‐bis(3,4,5‐trimethoxyphenyl)‐1,4,5,8‐naphthalenediimide (NDI‐DTMA), containing a donor–acceptor–donor (D–A–D) structure. The D–A–D architecture significantly enhances π‐conjugation extent of single organic material while narrowing its bandgap, facilitating electron transportation along the NDI‐DTMA skeletons. Moreover, 3,4,5‐trimethoxyphenyl groups not only suppress dissolution issue but also enlarge the intermolecular planar spacing for Na+ mobility through constructing efficient transport channels. As an electrode material for SIBs, NDI‐DTMA achieves a reversible capacity of 200 mAh g−1 after 2000 cycles at 1 A g−1 owing to its fast Na+ kinetics. Through systematic investigation on the anomalous capacity increase and the dynamic evolution of solid electrolyte interphase (SEI), we have elucidated the fundamental mechanisms that the distinctive NDI‐DTMA architecture enables exceptional energy storage performance. This work pioneers a design paradigm of organic small molecules that simultaneously address low solubility, high conductivity, and rapid ion transport, thereby providing a transformative strategy for SIBs.