Poly(N-vinylcarbazole) (PVK) as a high-potential organic polymer cathode for dual-intercalation Na-ion batteries

Poly( N -vinylcarbazole) (PVK) containing the electron-rich carbazole moiety is exploited as a high-potential and high-capacity organic polymer cathode for dual-intercalation Na-ion batteries, which exhibits redox potential in the range of 2.5–4.6 V (vs. Na + /Na) and theoretical specific capacity of ~138 mAh g −1 . After proper optimizations, PVK can deliver average discharge capacities of ~110 mAh g −1 for 100 cycles under a low current density (50 mA g −1 ) and ~62 mAh g −1 for 900 cycles under a high current density (0.5 A g −1 ) using 1 M NaPF 6 in ethylene carbonate (EC) and diethyl carbonate (DEC).