Tailoring π-Conjugated Systems: From π-π Stacking to High-Rate-Performance Organic Cathodes

Abstract

Summary Organic sodium-ion batteries (OSIBs) have numerous promising advantages for foreseeable large-scale applications, particularly including the convenience of performance optimization through molecular design. However, the reported organic cathodes still suffer from limited capacity, low cyclability, and poor rate performance. The tailoring of the π-conjugated system reported here can enhance the π-π intermolecular interactions, leading to insolubility, long-range layer-by-layer π-π stacking, fast-charge transport, and extraordinary stability and ionic conductivity (10−9 cm2 s−1). Consequently, the obtained cathodes delivered high electrochemical performance with high capacity (∼290 mAh g−1), superior fast-charge-discharge ability (∼160 and 100 mAh g−1 at 10 and 50 A g−1, respectively), and ultra-long cycle life (capacity as high as 97 mAh g−1 after 10,000 cycles at 50 A g−1).