The charge–discharge characteristics of Li/poly(N-methylaniline) (PNMA) coin cells with an ethylenecarbonate–dimethylcarbonate mixture containing 1M LiClO4 as electrolyte are studied. The PNMA is modified from a p-doped polymer to a self-doped polymer by a simple sulfonation procedure and its performance in a rechargeable cell is evaluated. Parallel experiments on polyaniline and sulfonated polyaniline are also performed. The application of the low band-gap polymer polyisothianaphthene (PITN) in a non-aqueous rechargeable cell and also in a capacitor is studied.