Self-carbonization of soluble organic cathodes enables stable Na-ion batteries

Small-molecule organic cathodes in sodium-ion batteries (SIBs) face the challenge of dissolution. Herein, surface self-carbonization electrodes was proposed to overcome this bottleneck. As a proof concept, new soluble small-molecule compound [N,N′-bis(2-anthraquinone)]-1,4,5,8-naphthalenetetracarboxdiimide (NTCDI-DAQ) designed. Through precise control carbonization temperature and time under an inert gas atmosphere, carbon layer with thickness 30–40 nm successfully formed on NTCDI-DAQ particles, which eliminates dissolution without affecting electrochemical properties particles. After 10,000 cycles at 1 A g−1, NTCDI-DAQ@C exhibits excellent discharge capacity 155 mA h g−1 half cells. In full cells Na3Bi anode, can achieve peak 245 g−1cathode maintain ultra-stable 223 after 200 0.1 g−1. The cathode performance is one best among reported for SIBs. Moreover, outstanding integrated NTCDI-DAQ@C//Na3Bi SIBs comparable that state-of-the-art