Study of charge compensation during the redox process of self-doped polyaniline in aqueous media

One of the most important problems associated with use of polyaniline as a cathode material in rechargeable lithium batteries is related to energy den sity degradation due to the predomination of anion participation in the cha rge compensation process. This work describes the synthesis of a self-doped polyaniline, poly-(aniline-co-N-propanesulfonic acid-aniline), and evaluat es its properties in aqueous acid solutions, with special attention to the increase of proton participation in the electroneutralization mechanism. Th e characterization was carried out using elemental analysis, FTIR and UV-vi s spectroscopies. Electrochemical properties were investigated with the ele ctrochemical quartz crystal microbalance and cyclic voltammetry. The result s obtained show that proton participation was increased for the redox proce ss of poly-(aniline-co- N-propanesulfonic-acid-aniline)in relation to polya niline.