Electrochemical intercalation of cationic and anionic species from a lithium perchlorate-propylene carbonate system - a rocking-chair type of dual-intercalation system

The reductive and oxidative intercalation of ionic species of lithium perch lorate (LiClO4,) in propylene carbonate (PC) medium are carried out to deve lop a dual-intercalation battery system. Cyclic voltammetry (CV), potentios tatic transients (i-t), galvanostatic charging, thermogravimetry (TG) and d ifferential thermal analysis (DTA) are performed to establish the intercala tion behaviour of both lithium and perchlorate ionic species. A polypropyle ne graphite composite electrode material containing 20 wt.% polypropylene a s a binder is found to be a suitable host material for dual intercalation s tudies. The intercalation/de-intercalation efficiency (IDE) increases with increasing sweep rate and reaches up to 90% for Li+ and 65% for ClO4- ions at a sweep rate of 40 mV S-1. The formation of a passive film decreases the IDE during the first intercalation/de-intercalation cycle. The open-circui t potential for a battery assembly involving these two electrodes is in the range 3.8 to 4.0 V. (C) 1998 Elsevier Science S.A. All rights reserved.