Poly(diphenylaminesulfonic acid sodium) as a cation-exchanging organic cathode for sodium batteries.

A Na-rich poly(diphenylaminesulfonic acid sodium) (PDS) is prepared by oxidative polymerization and tested as an organic Na-host cathode for Na-ion batteries. Due to the highly self-doped benzenesulfonic anions grafted on the polyaniline backbones, this redox-active polymer demonstrates a reversible capacity of 100 mAh g − 1 at an average potential of ~ 3.4 V, reaching its theoretical value of reversible 1 Na insertion/extraction reaction. In addition, this polymer cathode also exhibits considerable rate capability and cycling stability, possibly serving as a low cost and sustainable cathode of Na-ion batteries for widespread electric storage applications. [ABSTRACT FROM AUTHOR]