Precise synthesis of BN embedded perylene diimide oligomers for fast-charging and long-life potassium-organic batteries

Replacing the C 00000000 00000000 00000000 00000000 11111111 00000000 11111111 00000000 00000000 00000000 C bond with an isoelectronic BN unit is an effective strategy to tune the optoelectronic properties of polycyclic aromatic hydrocarbons (PAHs). However, precise control of the BN orientations in large PAH systems is still a synthetic challenge. Herein, we demonstrate a facile approach for the synthesis of BN embedded perylene diimide (PDI) nanoribbons, and the polarization orientations of the BN unit were precisely regulated in the two PDI trimers. These BN doped PDI oligomers show great potential as organic cathodes for potassium-ion batteries (PIBs). In particular, trans-PTCDI3BN exhibits great improvement in voltage potential, reversible capacities (ca. 130 mA h g-1), superior rate performance (19 s to 69% of the maximum capacity) and ultralong cyclic stability (nearly no capacity decay over 30 000 cycles), which are among those of state-of-the-art organic-based cathodes. Our synthetic approach stands as an effective way to access large PAHs with precisely controlled BN orientations, and the BN doping strategy provides useful insight into the development of organic electrode materials for secondary batteries. Three BN bridged PDI oligomers are synthesized and the BN orientations are precisely regulated in two trimers. All new compounds show great improvement in voltage potential, rate performance and cyclic stability in potassium-organic batteries.