Surface film formation on graphite negative electrodes in rechargeable lithium batteries

The choice of solvent is quite important to obtain good protecting surface film on graphite negative electrodes in rechargeable lithium batteries. A s ubtle difference of the molecular structure of solvent greatly affects the easiness of surface film formation. In order to understand the solvent effe cts and to elucidate the mechanism of surface film formation, morphology ch anges of the basal plane of highly oriented pyrolytic graphite were studied using electrochemical scanning tunneling microscopy (EC-STM). In this arti cle, our recent results of EC-STM observation in different solvent systems are reviewed.