Electrochemical intercalation of lithium ions into polyparaphenylene in LiClO4-carbonates electrolytes

The electrochemical intercalation of unsolvated lithium cations into polyparaphenylene (PPP) has been carried out in a EC/PC (1/1 volume) mixture using LiClO4 as lithium salt. It leads to formation of saturated materials with composition Li-0.5(C6H4). Cyclic voltammetry and galvanostatic measurements reveal three successive phase transformations in the intercalation-deintercalation process. The irreversible side reactions which occur during the first PPP reduction, like decomposition of the electrolytes (EC and PC) and reduction of the binder (PVDF), are responsible for an important capacity loss that decreases rapidly in the following cycles, The cells exhibit finally a good reversibility. (C) 1997 Academic Press.