Poly[bis(2-aminophenyloxy)disulfide]: A polyaniline derivative containing disulfide bonds as a cathode material for lithium battery

A new conductive polyaniline derivative containing disulfide bonds, poly[bis(2-aminophenyloxy)disulfide] (PAPOD), has been proposed as a high energy-storage material. PAPOD has been synthesized using a moderate oxidant ferric chloride and characterized by elemental analysis, X-ray photoelectron spectroscopy (XPS), FT-IR, FT-Raman, and UV–vis spectroscopy. The cyclic voltammograms of this polymer show that the intramolecular self-catalysis occurs between the conductive main-chain polyaniline (doping/undoping processes of the π-conjugated system) and side-chain disulfide bonds (scission/reformation processes of the S–S bonds) in PAPOD. Because the redox reaction of conductive main-chain polyaniline occurs in the same potential range as that of the side-chain disulfide bonds of this polymer, the Li/PAPOD test cell displays a charge capacity of 230 mAh g−1-cathode and an energy density of 460 mWh g−1-cathode, which is about 2–3 times higher than those of inorganic intercalation compounds.