Extended conjugated carbonyl-containing polymer as a negative electrode material for Na-ion batteries

A novel vinyl polymer bearing an extended conjugated disodium dicarboxylate structure, specifically, the terphenyl side chain structure, which has a favorable electrochemical performance, has been synthesized and evaluated as an anode for sodium-ion batteries. The electrochemical performance was significantly improved over that of the vinyl polymer with disodium terephthalate. In particular, the discharge potential shifted by similar to 0.1 V to a lower potential at 0.28 V (vs. Na/Na+). Additionally, a specific capacity of 121 mAh g(-1) at 10 mA g(-1), which corresponds to an 88% theoretical capacity, was observed. Moreover, better rate performance was also achieved through the extended pi-conjugated system.