Proton Self‐Doped Polyaniline with High Electrochemical Activity for Aqueous Zinc‐Ion Batteries

Abstract Aqueous zinc‐ion batteries are promising energy storage devices due to their low cost, good ionic conductivity, and high safety. Conductive polyaniline is a promising cathode because of its redox activity, but because the neutral electrolyte protonates only weakly, it displays limited electrochemical activity. A polyaniline cathode is developed with proton self‐doping from manganese metal–organic frameworks (Mn–MOFs) that alleviates the deprotonation and electrochemical activity concerns arising during the charge/discharge process. The MOFs carboxyl group provides protons to prevent deprotonation and allows the polyaniline to reach a high zinc storage redox activity. The proton self‐doped polyaniline cathode has a superior specific capacity (273 mAh g −1 at 0.5 A g −1 ), a high rate property (154 mAh g −1 at 20 A g −1 ), and excellent cyclability retention (87% over 4000 cycles at 15 A g −1 ). This research provides fresh insight into the development of innovative polymers as cathode materials for high‐performance AZIBs.