A sulfonated polyaniline with high density and high rate Na-storage performances as a flexible organic cathode for sodium ion batteries

A Na-rich cathode is developed by grafting the electron-withdrawing -SO3Na group on polyaniline chains. Due to the immobile doping and effective activation of the sulfonate group, this polymer demonstrates a high capacity (133 mA h g(-1)) and excellent cyclability through a cation-exchange reaction, offering a low cost and sustainable cathode for SIBs.